This PDF file contains the front matter associated with SPIE Proceedings Volume 12976, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

High performance infrared lens used in aerospace optical remote sensing systems have great benefit in resource exploration, pollution monitoring etc. However the high technical threshold of manufacture, the production and launch cost due to the heavy infrared optical materials, and the long period of alignment have restricted its use especially for civil and commercial aerospace. Here we present a realization of aerospace infrared lens for mass production. An unique opto-mechanical structure design has been implemented in order to meet the requirements of the mass production of space infrared lens. Some high effective, low cost processing technology are used both for optical and mechanical parts. The produced lenses have the biggest diameter of 300mm and the best RMS of λ/50(λ=632.8nm). A smart alignment based on an online device with lens alignment and image quality measurement reduces the period from 30 days to 7 days. With the well assembled infrared lens, the space camera has a system wavefront of 0.1λRMS (λ=3.39μm) and the MTF of 0.38(@25lp/mm).

Large deviation aspherical element refers to an optical element with large asphericity and sharp curvature changes. It plays an important role in constructing modern optical system. However, widely used passive smoothing technology cannot meet the need of producing smooth large deviation aspherical element. Thus, an active smoothing technology was creatively used in the current research, aiming to reduce the mid-spatial frequency (MSF) error of the surface of large deviation aspherical element. To reach the objective, an off-axis smoothly-processing model was constructed. It offers important information about the degree of coincidence between grinding lap and large deviation aspherical element. Finite element analysis was also conducted to examine the relationships among material, thickness, and structure of grinding lap during the active smoothing process, and to obtain optimal active smoothing parameters. Finally, a complete processing process for large deviation aspheric elements was constructed and used for machining experiments. The result suggested that the off-axis smoothly-processing model has high accuracy, and the smoothing technology in this paper is effective to decrease the MSF error of the surface of large deviation aspherical element.

The Solar Upper Transition Region Imager (SUTRI) is an extreme ultraviolet solar imaging telescope that focuses on dynamically observing the solar transition region within a narrow band at 46.5nm. This paper describes the optical parameters, optomechanical structural design, finite element simulation, and on-ground environmental testing. To satisfy the narrow band requirement, the telescope employs multilayers coated on Ritchey-Chrétien optics and filters mounted at the front aperture and ahead of the focal plane. The primary and secondary mirrors are glued to invar frames that provide peripheral support. The telescope contains three mechanisms, which are a focus mechanism, a filter wheel, and a front door. In addition, this paper carried out finite element simulation of modal analysis, optical performance and structural strength. These simulations verified that the opto-mechanical system design is feasible. Finally, the telescope successfully underwent a series of on-ground environmental testing and was subsequently launched carried by SATech-01 satellite in July 2022.

Select the initial structure of the optical system. On this basis, the initial structural parameters of the optical system are calculated, and the initial structure of the optical system is determined, and the optical performance of the initial structure is analyzed. The essence of the optimization of the optical system is the correction of aberration. Therefore, the optimization parameters are determined to optimize the design of the optical system and verify whether it can meet the imaging requirements.

Aspheric diffractive lens (ADL) has been widely used in wavefront shaping and infrared field as it can realize optical system aberration elimination and chromatic aberration correction. However, the fabrication of high-precision glass ADL is a challenge. In this paper, A manufacturing method is proposed for high-precision aspheric diffraction mold (ADM), including mold substrate and plating selection, plating layer heat treatment, and single-point diamond turning (SPDT) process. The mold is pre-compensated to improve the molding accuracy based on the simulation-predicted form error of glass ADL. Based on the machined high-precision ADM, an ADL with an aspheric form accuracy of 0.2133 μm, a diffraction zone with a form accuracy PV of 22.5- 95 nm, and a surface roughness Sa of 2.813 nm was fabricated using a multi-step heating and annealing molding process.

Numerical simulation of glass molding and research on material viscoelastic have become increasingly important with the deepening of glass molding research for optical devices. In this study, we developed an accurate and efficient numerical simulation method for the glass aspherical lens molding process. According to the FEM simulation results of aspheric lens molding, gas trapping occurred in the molding of preforms of size 5 mm, which was consistent with the experimental results. The molded lens was tested by profilometer and a gas trapping area of about 3 microns deep and hundreds of microns wide existed at the top of the lens, which was also consistent with the FEM analysis results. The consistency of the FEM predicted results with the experimental results illustrated that the Coupled Eulerian-Lagrangian (CEL) method can be used for the prediction of the gas trapping phenomenon in aspheric lens molding. This study provides a reference for the numerical simulation and process optimization of the glass molding of optical device

At present, the object detection algorithm based on deep learning has gradually replaced the traditional object detection algorithm and become the main research algorithm in object detection and other tasks. For target detection under infrared conditions, the characteristics of infrared heat map will affect the ability of target detection and extraction, resulting in the impact of detection accuracy and speed. In order to solve the problem of low detection accuracy of YOLOv5 in industrial infrared scenes, this paper improved its network model structure, added NAM attention mechanism, and improved the feature pyramid network in the model. In this paper, all experimental results are summarized: the improved YOLOv5 network model not only has better detection accuracy but also improves detection speed, which can better meet the requirements of infrared heat map defect target detection.

In order to realize the observation ability of a space camera with the field of view angle greater than 120 degrees and the imaging spectrum covering 350nm~ 12500nm, the design and verification of a scanning system with large field of view and multichannel were carried out. Firstly, according to the performance indicators of the camera, the structure form of the overall scanning and imaging system was determined. Two motors were used to drive the telescope system and the half-angle mirror to rotate in the same phase respectively, and by imaging with four refractive relay optical systems in different spectral bands, the camera could achieve a wide field of view imaging covering the ultraviolet to long wavelength infrared spectral range. Secondly, based on the scanning form, the optical parameters and the system structure were designed in detail. Finally, the system was alignment, and the performance of the system were measured in experiment. The wavefront aberration of each field of view in the telescope system was better than 0.047λ (λ= 632.8nm). The scan following accuracy of the half-angle mirror was better than 10″, with a deviation of 0.01mm from the scanning axis position of the telescope system. All field of view MTF_avg of the four channels were better than 0.42, meeting the indicator requirements. The results show that the design of this scanning system with large field of view and multichannel is reasonable and feasible, and has important reference value for the development of related systems.

A novel subaperture stitching method based on monoscopic deflectometry in single point diamond turning is introduced in this study for measuring large-aperture optical surfaces. This method not only solves the phase position deviation between subapertures, but also eliminates the system calibration error. The objective optimization is achieved by utilizing the gradient deviation and form deviation at the overlapped areas of adjacent subapertures. To achieve full-aperture measurement of the SUT, the global gradient is integrated to reconstruct the SUT. Experimental validation confirms the feasibility of the method.

The thermal deformation of silica glass reflectors employed in high-power laser systems has emerged as a critical issue, imposing limitations on the scalability of lasers to achieve high average power and high beam quality. Water-cooling is the most effective and commonly employed method for reducing thermal deformation. However, it is challenging to create embedded microchannels for water-cooling in silica glass by conventional processing methods. In this study, we demonstrate a novel method for fabricating silica glass microchannel reflectors by combining glass slurry UV-curing with 3D printing of polymeric microchannels. The glass slurry consists of SiO₂ nanoparticles and organic resins, which can be UV-cured and subsequently transformed into fused silica glass through heat treatment. During the UV-curing process, the 3D printed polymeric microchannel structure is embedded within the glass slurry. Subsequently, in the heat treatment process, the polymeric microchannel structure is removed, leaving behind the corresponding hollow cavity. The photocurable resin used for printing microchannels is optimized to ensure a crack-free sample. The sintered sample shows an isotropic shrinkage of 28%. Microchannel structures with different shapes are created. The water tightness of the fabricated reflectors is validated by injecting red ink into the microchannels.

This paper presents a roll-to-plate hot embossing process (R2PHEP) for precision manufacturing of optical microstructures on polymethylmethacrylate (PMMA) surface. The viscoelasticity of PMMA at embossing temperature is described by the General Maxwell model. The finite element numerical simulations of R2PHEP are carried out to optimize the process parameters, including mold temperature, roller radial displacement, and mold feed rate. The optimized parameters are used in the R2PHEP to fabricate the desired optical microstructures. The results show that R2PHEP is capable of precision manufacturing of complex and high precision optical microstructures on PMMA surfaces, making it a promising technology for efficient preparation of optical microstructure components.

A VIPA-based spectrograph with ultra-high resolution and wide band was designed and built by the astronomical photonics team in NIAOT. The fiber-fed spectrograph is compact (W × D × H: 350 mm × 350 mm × 150 mm) and designed to operate without temperature control measures. The spectrograph also provides a fast and accurate measurement of linewidths. Here we report the performances of the VIPA spectrograph, such as the spectral resolution and coverage, the precision of linewidth measurements, the stability with ambient temperature and data acquisition rate, etc.

Temporary sources and explosive celestial bodies in the universe can only be observed through their high-energy radiation, for example X-rays. The multilayer nested Wolter-I type focusing mirror is widely used in X-ray astronomical telescopes. The electroforming replication process can achieve batch high-precision production of Wolter-I type focusing mirrors, with the process flow of mold ultra-precision turning, ultra-smooth, coating, electroforming, and demolding. The fabrication of molds accounts for a large proportion in the process, and the molds accuracy and surface quality directly determine the optical performance of the mirrors. We built the DRL2000 ultra-precision lathe for mold turning of mission EP (Einstein Probe) and eXTP (enhanced X-ray Timing and Polarimetry mission). The swing straightness error of the guide rail was separated and compensated through trial cutting and reverse measurement methods to achieve a turning generatrix accuracy of peak-to-valley (PV)<0.2μm. An in-situ measurement device has been built based on the ultra-precision lathe. After adjustment the system measurement error can be controlled within 0.1μm. The corresponding spiral measurement path and coaxiality error separation method were studied and verified through experiments. An offline measurement device was built and based on it, an optical lever measurement method was preliminarily validated. Finally, a division method of medium-low frequency error and medium-high frequency error was proposed.

The focal plane of remote sensor is an important part in the development of remote sensor. At present, the single detector module can not meet the requirements of linear array due to the influence of detector material, processing technology, detector scale, resolution, spectral band number and other indicators. Therefore, in order to meet the need of large field of view of remote sensing camera, it is necessary to arrange the detectors in a certain way, and form a long pixel to meet the field of view. This paper presents the characteristics of various common stitching methods and summarizes the application of various stitching methods in remote sensors.

Surface-enhanced Raman spectroscopy provides a highly sensitive and non-destructive technique for surface analysis. In this paper, we developed a high-performance and transparent surface-enhanced Raman spectroscopy (SERS) sensing device which can be used as non-destructive and non-invasive analytical technique. The SERS device is composed of sandwiched transparent plasmonic flowers (STPF), which is a two-layer structure with the analyte placed between the two layers. The top layer is a quartz chip with arrays of Ag plasmonic flowers and the bottom layer is Ag thin film on silicon surface. The plasmonic flowers array provides “hot spots” while allowing laser and Raman scattering light to pass through the top layer for excitation and acquisition of Raman spectra from the backside. Ag flower arrays were prepared using a combination of near-field exposure and ion beam etching. Where the individual petals were spaced uniformly between each other and between the flower centers. We performed SERS detection of the fluorescent dye R6G using STPF. The STPF had a strong Raman enhancement effect with an enhancement factor of up to 10⁷. Furthermore, the SERS device has good uniformity and repeatability with an RSD (relative standard deviation) of 9.23%. In summary, we have created transparent, sensitive and reproducible SERS device.

With the development of 6G communication technology, satellite Internet will become an important means of achieving global network coverage and high-speed network transmission. The non-uniform distribution of ground equipment and the high-speed mobile characteristics of non-geostationary orbit (NGSO) satellites have created obstacles to the provision of services from satellites to the ground. Reasonable resource management in the multibeam satellite technology system can effectively guarantee that the service demand of ground users can be responded to in time and the resource utilisation rate of users can be improved as much as possible. In this paper, the multibeam satellite system is sorted out from the overall point of view. We also discuss the current work of Artificial Intelligence (AI) in the multibeam satellite processing process to illustrate the key role played by AI in it. Finally, we discuss potential open issues with the aim of providing some insights into the development of multibeam satellite communication systems and their application in AI techniques.

EMFF (Electromagnetic Formation Flying) is a novel concept of controlling magnetic moments to create interaction electromagnetic forces and torques between different satellites in a formation which enables the life-span of the mission independent of the fuel available on board. This great advantage comes at the cost of coupled and nonlinear translational dynamics of the relative motions, especially for multisatellites formation. The control for EMFF becomes a very challenging problem because the translational dynamic of each satellite is coupled to that of every other satellite in the formation since changing the magnetic moment strength on one satellite affects every other satellite in the formation with a non-zero magnetic dipole. This paper presents a consistency control law for EMFF that enables formation reconfiguration and maintenance with electromagnetic force, at the same time avoids any potential collision. Closedloop numerical simulation shows the feasibility and reliability of the control scheme described for EMFF.

This paper proposes a frige phase-shifting technique based on the diffusion model. Phase-shifting interferometry is a commonly used method in white-light interferometric measurements, where phase shift values used as known quantities for analyzing the fringes. However, when the measurement environment introduces significant disturbances, the quality of recorded fringe patterns at different time intervals for phase shifting decreases, making it difficult to perform real-time measurements and in-line inspections in highly interfered processing environments. Additionally, the phase shift error introduced by the lead zirconate titanate (Pb[Zr_x Ti_1−x]O₃ or PZT) phase shifter easily deviates the phase shift values from their ideal values. The implemented virtual phase shifter in this study utilizes a diffusion model, which allows for the input of a raw, noise-contaminated fringe pattern and produces a noise-free fringe pattern after phase shifting. Experimental results demonstrate that our method can generate clear fringe patterns and accurately restore phase information even when the signal-to-noise ratio is 0.5 dB. The residual Peak-to-Valley (PV) and Root Mean Square Error (RMSE) values compared to the true phase are 0.8867 rad and 0.0779 rad, respectively.

When a high-power laser beam is incident on water, the rapid heat transfer process triggers ionization of the water in the active region, resulting in an explosion as well as outward propagating shock waves. Here, the formation, propagation, and interaction of underwater shock waves induced by nanosecond laser pulses were experimentally investigated. By fitting the theoretical model (Sedov-Taylor expansion model) to the experimental results, we quantified the effective energy carried by the shock wave during propagation. Numerical simulations with an analytic model using the distance between adjacent breakdown locations as input obtain the shock wave emission images at different time delays and provide insights into experimentally not accessible shock wave parameters. An empirical model is used to describe the pressure behind the shock wave. The results show the near-acoustic propagation behavior of the shock waves at longer time delays. On top of that, we compared the effect of the distance between adjacent excitation positions on the shock wave emission process. The shock wave parameters in the far field are more accurate and easier to perform. Furthermore, utilizing multipoint excitation offers a flexible approach to delve deeper into the physical mechanisms that cause optical tissue damage in nanosecond laser surgery, leading to a better comprehension of the subject.

With the rapid development of IoT, more and more sensors are deployed in areas that lack infrastructure such as marine areas. We propose a new ISE-IoT scenario by combining the transmission of IoT data from the ocean via vessels, aircraft or LEO satellites, and use LEO satellite networks to fuse with DTN to fully exploit the advantages of both, and design a new high-performance routing protocol with low latency, low packet loss, and low overhead called DHOR. DHOR is able to carry data through the mobile characteristics of vessels and aircraft carry data and set the transmission threshold according to the remaining data survival time, and when the threshold is reached, the data is efficiently transmitted to the destination through LEO satellite intervention. The simulation experimental results are consistent with the ideal results and reflect the effectiveness of the routing algorithm.

With the development of computing capability onboard, satellite-terrestrial integrated network presents characteristics such as large scale, complex topology, and heterogeneous and diverse resources, making it difficult to accurately adapt to the resource requirements of different services. This article analyses the diverse and heterogeneous computing and networking resources in satellite-terrestrial integrated network, and presents an intelligent resource management and control architecture. This architecture aims to achieve intelligent collaborative management of multi-dimensional and multi-domain computing and networking resources in space and ground, and to provide resources for diverse scenarios as needed. Based on the proposed architecture, a knowledge space-based resource management mechanism is proposed to achieve deep integration of computing, data, algorithms, and networks, and to improve the effectiveness of resource orchestration. Meanwhile, a highly dynamic end-to-end network slicing management mechanism is presented to adapt to the differentiated needs and to provide on-demand network services for users. Finally, the experimental results showed that a dynamic deployment policy for the satellite-terrestrial integrated network can be generated in just 1.3 seconds using the greedy algorithm to meet the computing and networking resource requirements of the service scenario on a scale of 20 satellites, which verified the rationality and effectiveness of the intelligent resource management architecture.

A Ku/K band dual-band circularly polarised wide-angle scanning phased array antenna is presented. The upper layer of the Ku antenna unit radiates using a patch antenna, and the lower layer is fed by a dual port with equal amplitude and phase difference of 90°using a 3dB bridge with a stripline structure, generating two circularly polarised waves of equal amplitude and opposite rotation; The K-band circularly polarised antenna unit uses a square patch in the upper layer for radiation, and a metal probe structure in the lower layer to transmit electromagnetic energy to the patch antenna, fed by a dual-port feed with an equal amplitude phase difference of for the 3dB bridge of the stripline structure. By optimising the antenna array arrangement, the gate flap is reduced and the antenna gain is increased. The simulation results show that S11 is less than -10dB at both Ku-band (12.25Ghz-12.75Ghz) and K-band (17.7Ghz-21.2Ghz) and the 3dB axial ratio bandwidth reachesrange. The antenna unit is used to form a 1*5 antenna array to verify the antenna performance, and the simulation results show that the antenna array can cover a range of ±60°beam scanning.

With the increasing capabilities of satellites and the growing demand for emergency response, traditional centralized or distributed planning approaches are insufficient for collaborative planning of batch arrival emergency tasks (BAETs) due to communication surge and cyclic problem-solving issues. This paper addresses the challenge of coordinating BAETs in a distributed satellite environment. To overcome the issues of communication surge and cyclic problem-solving caused by batch arrivals, a Two-Layer Tabu Search-Based Distributed Collaboration Method (TLTSD) is proposed. TLTSD combines traditional auction-based self-organized collaboration method with tabu search approach, where the Master satellite acts as an auctioneer and the Servant satellites act as bidders, each maintaining their own tabu list to avoid cyclic optimal solutions during subsequent negotiations. Through numerical experiments, TLTSD is proven effective in reducing communication times and enhancing coordination performance.

EP satellite is a scientific exploration satellite for time-domain astronomy and high-energy astrophysics, its function is to carry out high-energy transitory celestial body survey with the highest sensitivity in the soft x-ray band. EP will be equipped with two groups of x-rays focusing mirrors (each group contains 54 Wolter-I mirrors). An x-ray focusing mirror is used to collect x-ray radiation in the universe, and is the core component of an x-ray astronomical satellite observation payload. The current x-ray focusing mirrors are derived from the Wolter-I reflector, and the light is focused through the inner surface. The inner reflection surface is an optical free-form surface connected by parabolic and hyperbolic surfaces. Many conventional measurement methods are not applicable and difficult to measure. High precision contact measurement is easy to scratch the mirror surface, Therefore, non-contact measurement must be used. In this paper, we develop two non-contact surface precision measurement devices are developed to solve the problem of difficult measurement of the inner reflection surface of the x-ray focusing mirror. One is a rapid measurement device based on the principle of optical star measurement method, The other is to measure the mirror inner surface by a single point scan measurement, the optical triangulation method is selected as the principle of the measurement device. We then verified the measurement accuracy of the mirrors with a precision visible light test system. In order to further verify the measurement accuracy of the focusing mirrors, x-ray testing of the focusing mirror was carried out at the 100-meter vacuum x-ray calibration facility of the Institute of High Energy Physics, Chinese Academy of Sciences. The x-ray measurement results are better than the project index requirements.

The utilization of sub-aperture processing technology in optical component manufacturing introduces mid-spatial frequency errors that significantly impact the imaging quality of optical systems. Effectively mitigating these mid-spatial frequency errors has consistently presented a challenging focal point within the realm of optical component manufacturing, with complexity arising in the endeavor to eliminate mid-spatial frequency errors in aspheric optical components. To address this intricate task, this study adopts a smoothing polishing process for a series of comprehensive experiments. Initially, the configuration and composition of the smoothing polishing tool are elucidated, providing a clear understanding of its structural intricacies. Subsequently, an in-depth analysis of the underlying theory governing the smoothing process is undertaken. This theoretical foundation sets the stage for the subsequent execution of multiple smoothing experiments, carried out with a deliberately chosen set of smoothing process parameters. The insights derived from these experiments illuminate the distinct characteristics of the smoothing process. The outcomes of these experiments hold significant implications for refining the smoothing process of aspheric optical components. The empirical findings serve as a valuable guide in enhancing the precision and efficacy of the smoothing procedure, thus contributing to the improvement of optical component manufacturing and the broader field of precision optics.

The fabrication of three-dimensional (3D) wrinkle architectures has garnered extensive attention from both the academic and industrial sectors. Ultrafast laser 3D nanoprinting allows for the fabrication of intricate 3D wrinkle architectures, offering precise control over fine morphological characteristics. The temperature modulation induced by the ultrafast laser along the scanning path triggers a volume change in a thermal-responsive polymer, resulting in the surface instability of printed voxel lines. The printing process involves an external field coupling effect of photopolymerization, photothermal interaction, responsive deformation, and substrate adhesion. Based on recent theoretical studies on swell-induced surface instability, we simplified the layered polymerized structures as a plane film attached to an underlying substrate and focused on the essential physical features that determine the instability patterns, including mismatch strain, mechanical properties, and adhesion energy. Various modes of surface instability patterns in solid and hollow units are categorized, and an analysis model that accounts for diverse surface instability patterns in solid and hollow microgel units is constructed. The proposed analysis model not only improves the understanding of 3D nano-wrinkled structures but also paves the way for extending wrinkle applications.

The micro-structure of materials has a crucial role in the macro properties of materials. In order to study the potential application of turning the proper machining properties of polymer materials through influencing the micro-structure, this paper makes use of the easy-controlled magnetic field to assist the polymerization process of the polymer composites. The preliminary results show the connection between the micro-structure and macro properties of polymer composites and the possibility of modifying the polymer by turning the micro-structure of the polymer.

Based on the requirements of rapid and low cost construction for large-scale satellite constellation construction, combined with the characteristics of high-speed, small size and low power consumption of space laser communication, satellite to ground and satellite to satellite full link laser communication constellation is designed, the communication system and wavelength were analyzed and selected, and key technologies for space-based laser transmission were proposed to address issues such as weather impact, rapid acquisition, and high-precision pointing in satellite to ground laser link communication, providing reference for large-scale satellite constellation design.

As a key subsystem of step and scan projection lithographic machines, the three-degree-of-freedom leveling and focusing stage always fails to achieve ultra-precision motion because its control system cannot achieve complete decoupling. Taking up this challenge, in this paper we propose a complete decoupling control method containing static decoupling and dynamic decoupling based on nonlinear active disturbance rejection control (ADRC) for the stage. First, by setting virtual control variables, the three-input three-output coupled system is transformed into three nearly independent single-input singleoutput systems. Then, the nonlinear ADRC is utilized to solve the residual coupling caused by coupling model inaccuracies. Finally, the simulation results show that the proposed control method has better robustness and disturbance rejection ability than feedforward compensation PID control and linear ADRC.

SiCp/Al composites are suitable for manufacturing optical devices in various harsh environments such as mirrors, lenses, etc., and have broad application prospects in optics. The effective surface removal of the SiCp/Al composite is difficult due to irregular SiC-reinforced particles inside, resulting in the surface quality not being ideal. Therefore, it is necessary to study the removal mechanism of SiCp/Al composite materials. In this study, a statistical analysis based method was introduced to establish a particle random distribution model for SiCp/Al composite materials with a volume fraction of 30%. The removal mechanism of the composite material was revealed through a combination of simulation and experiments. In this study, the Sa20nm mirror was obtained by setting reasonable parameters. This study can provide a reference value for the removal mechanism and processing research of SiCp/Al composites.

Nowadays, lots of vision devices have set in the industry process. The vision detect results from the devices have higher requirements for data storage and network transmission. Unattended vision detection technology has become the key research directions of multispectral optoelectronic devices. However, it has different needs about the architecture of the 5G network and how to design the system with unattended work for petrochemical industry. So it is quit necessary to find a root to study optoelectronic device using 5G network, in order to get the real-time transmission of results, and edge processing. This paper introduces the architecture unattended inspection system for petrochemical industry 5G network, composition system of multispectral optoelectronic devices. Finally, we have developed a use case of unattended vision inspection architecture based on 5G network structure. And also we have analysis the related applications in the petrochemical industry application scenario.

The low orbit satellite network has features such as high-speed information transmission and on-planet routing exchange, in which the satellite-ground feeder link (the link between the satellite in the space segment and the gateway station in the ground segment) realising high-speed bidirectional communication between the satellite and the gateway station on the ground, and performing important functions such as user access to the terrestrial network and control and monitoring of the satellite by the ground management and control center. In fact, the satellites in the low orbit constellation move at high speed relative to the ground, and the feeder link from the low orbit satellites to the gateway station has a lot of mobile switching, so it is necessary to solve the routing addressing problem between the gateway station and the satellites under the conditions of dynamic switching of the feeder link in the low orbit satellite network, which is the need to design the link table between the satellites and the gateway station at the engineering level. However, the complex configuration of low-orbit giant communication constellations, the large number of satellites and the suddenness of working modes have brought great challenges to the generation of link strategies for the constellation satellites and the ground gateway stations at the system level. In order to solve the problem of efficiently generating link building strategies for giant constellations and many gateway stations, this paper proposes a dynamic and autonomous link table building algorithm based on maximum matching of bipartite graphs. First, a low-orbit constellation model and an access model of low-orbit constellations and gateway stations are established based on orbital dynamics, then a dynamic autonomous generation algorithm based on maximum matching of bipartite graphs is designed to balance the system load, and finally simulations a re performed to validate the algorithm in typical application scenarios. The simulation results show that the dynamic autonomous chain building strategy based on maximum matching of bipartite graph for giant constellation feeder catching and following proposed in this paper is universal, which can improve the autonomous operation capability of the system a nd reduce the operation cost of the system.

Various applications of microlens arrays in optical measurement, optical sensors, digital displays, optical communications and other fields have attracted widespread attention, among which it is always difficult to directly machine those convex microlens array made of brittle materials. Polyhedral microlens array is relatively easy to be generated; however, there are few researches found on the design of polyhedral lenses. In this paper, the method of meridional plane integral is proposed for the design of polyhedral microlens array. For a square aperture microlens array that fits the detector pixel shape, the method firstly determines the limit of its light boundary conditions on the vector height and then analyzes each meridional plane to form the final optimal design result using the multi-surface integral. The results show a better focusing effect under multiple fields of view, with a central 0-degree field of view where the spot is focused to within 17% and an edge 5-degree field of view where the same degree of focus is obtained. Meanwhile, the filling factor is theoretically 100%. The research is helpful for new design of microlens arrays considering the manufacturing capability.

Digital fringe projection (DFP) measurement technology has been widely used in research and industry due to its characteristics of fast measurement speed and easy implementation. However, when measuring objects with large surface undulations, the depth of field limitations of the camera and projector will cause part of the object to be measured to be in a state of defocus, which will reduce the measurement accuracy. This paper presents a novel method to discriminate the portion of an image that is defocused due to depth-of-field limitations and to eliminate the error caused by defocus in the phase diagram. The proposed approach first discriminates the defocused pixels in the image based on the modulation information, and then recovers the defocused regions by the information fusion method. The information fusion fixes the erroneous phase information by fusing the valid phase of the neighboring focused region with the phase of the defocused region obtained through kernel density estimation by means of the Kalman filter algorithm. Simulation and experimental results show that this method can effectively eliminate the errors caused by the depth-of-field limitation in the phase map, and can feasibly extend the depth of field of the digital fringe projection system without projecting additional images.

With the advances in scientific foundations and technological implementations, modern industrial design requires more details of object such as 3D information. Most of the optical 3D metrology focus on the spatial distribution of the light field, while weakening its temporal characteristics, which makes additional information lost or causes errors in somewhere. Here, we propose a new approach based on the temporal modulated radiation, actively introduce time perturbation and mine the hidden information in the temporal domain intensity fluctuations of the light field. A temporal cross-correlation function is used to calculate and characterize the related physical quantities of temporal light field, modeling the mapping relationship between the phase gradient of the modulated wave and the gradient of the object surface, and the feasibility of the model is verified by numerical simulation based on ray-tracing method. The proposed approach expands a new perceptive for optical metrology, provides a bridge for the integration of various technologies.

Fresnel lenses have become the mostly used concentrator in concentration photovoltaics (CPV) due to its thinness and high concentration. Typical Fresnel lens design principle requires the focal length much greater than its diameter, posing potential spatial confinement to CPV configuration. In this paper, a CPV with concentration ratio of 245 at 3.5 mm from the center of the lens is designed, featured with a double-sided circular Fresnel lens (20 × 20). For traditional PMMAbased Fresnel lens, a long focal-length is required to avoid the concentration efficiency loss on the edge of the grooves due to total reflection. To overcome the limitation, a theoretical model of double-sided Fresnel lens is proposed. In this model, groove parameters of the rear surface are carefully tuned to pair the refracted light from the front surface in order to achieve desired ray deviation. Uniform radiation and an angle tolerance for incline illumination of 6 degrees is also taken into account to ensure the overall performance of the concentrator. The design shortens the axial working distance between the concentrator and the photovoltaic cell, in order to create a more compact CPV module or satisfy some spatial-confined CPV applications.

To achieve high-resolution intensity images, Fourier ptychography (FP) has been used in microscopic for decades, and is suitable for macroscopic area. Aberration is important for the quality of reconstruction during aperture scanning and phase recovery in the FP process. In the field of macroscopic imaging, due to the defocus in the 3D scene, cameras can only capture blurry images by direct photography. To overcome the limitation, we design an FP iteration method with the depth of defocus to improve the recovery for the high-resolution images. The initial scene comprises two layers of data: the intensity information and the depth map. The spectral distribution and optical transfer function are acquired via Fourier transform. This is followed by an iterative process of reconstruction: a low-resolution image is taken at each aperture, combined with depth-induced defocus aberrations, and then substituted into optical transfer function calculations to simulate intensity measurements from camera sensing. Each scan corresponds to a specific area with limited bandwidth in Fourier space, and multiple iterations are used for phase recovery to reconstruct a high-resolution image. Compared to the traditional method, the defocus elimination FP algorithm for macroscopic imaging enhances the resolution and contrast of the reconstruction, enabling a wider range of measurable scenarios.

In order to solve the problem of high efficiency manufacturing and delivery of large-scale low earth orbit (LEO) constellation satellites, firstly, through investigation and analysis of the system composition, large-scale manufacturing solutions, and advanced manufacturing technology applications of typical LEO constellations such as GlobalStar, Iridium and OneWeb. On this basis, the key technologies involved in the large-scale manufacturing of LEO constellations, such as design for manufacturability, efficient testing and verification, additive manufacturing, virtual reality/augmented reality, and digital twin, were summarized. Finally, development suggestions for the large-scale manufacturing technology of LEO constellations were proposed from aspects such as innovating satellite design modes and methods, optimizing development processes and enhancing production capacity, building a satellite mass production quality control system and strengthening cost control at all levels

In this paper, the spatial positioning technology of off-axis optical elements is studied for the installation and positioning requirements of the off-axis mirror and the anomalous off-axis ellipsoid mirror in an optical system. In this paper, the assembly coordinate system is established according to the global coordinate system of space optical system. The key optical parameters of the optical system are accurately measured and controlled by the theodolite, laser tracker, interferometer and other instruments, so as to realize the precise positioning of the special-shaped off-axis optical element. Secondly, the optical characteristics of the system are analyzed by computer aided setting technology, and the optical misalignment is calculated according to the system wave aberration detection results. Thirdly, the attitude of optical element is adjusted precisely according to the amount of optical misalignment. After many iterations calculation and precision adjustment, the optical index requirements are finally achieved. The spatial positioning method of large size anomalous off-axis optical elements proposed in this paper provides an effective method for the spatial positioning and system assembly of anomalous off-axis optical elements in large aperture optical systems.

Three-dimensional reconstruction of highly reflective surfaces has always been an important and difficult problem in structured light technology. In this paper, a novel method by combining optimal exposure with the adjustment of the intensity of projection fringes by deep learning is proposed a single frame method is used to extract the overexposed region in the optimal exposure time series for composite projection. By using the statistical histogram of the number of overexposed pixels of the measured object under different projection conditions, and combining with the proportion of pixels in the image that are not exposed, the optimal exposure time series is calculated and the overexposed area is automatically extracted. The single-frame composite high dynamic image is obtained by adjusting the projection intensity through absolute coordinates, which improves the single-frame high dynamic range technique for highly reflective surfaces. Several simulations and experiments were conducted. The experimental results show that the proposed method can effectively improve the 3D reconstruction accuracy of the highly reflective surface, and the number of effective pixels in the point cloud can reach more than 98%.

Low-earth orbit megaconstellations have been developing rapidly in recent years and can provide Internet access services with wide coverage, low latency, and large capacity. Most of the existing megaconstellations are deployed in a phased, layer-by-layer manner. This has led to the discussion of single-layer constellations and the lack of research and analysis on the characteristics of multilayer constellations. To this end, the ground coverage characteristics of the multilayer low earth orbit megaconstellations and the dynamics of the intersatellite links between the layers are analyzed. The simulation results show that the coverage capability between 60° north and south latitude is significantly improved after adding the polar orbit satellite layer, and the polar coverage is further enhanced. At the same time, the establishment of interlayer intersatellite links is feasible. Although the range of interlayer links distance varies significantly and fulltime coverage is difficult to achieve due to the short link duration, the number of satellites on which interlayer links can be established is abundant. In addition, the interlayer links change periodically and predictably.

Ship detection plays a critical role in maritime safety and surveillance. Targets in high-resolution remote sensing imagery frequently have complex textures and shapes due to the rapid advancement of remote sensing satellite technology. These features can be efficiently captured and accurately detected by deep learning models. Due to the complicated harbor environment, a variety of ship types, and a huge volume of ships, ship detection based on high-resolution remote sensing photos is still a difficult problem when compared to generic object detection. For the purpose of detecting ships in high resolution remote sensing photos, this research suggests the EBENet method. In order to increase the model's precision, the entire method employs the lightweight network EfficientNet as the YOLOv5 backbone network and integrates the BiFPN and ECA attention mechanisms. The attention mechanism module helps the model to focus more on critical features, boosting the accuracy of ship detection, while the bi-directional feature pyramid network module integrates multiscale features to enhance the precision of object recognition. Additionally, research was done utilizing publicly accessible optical remote sensing image datasets to classify different ship types into three groups: Cargo ship, Warship, and Civilian ship. Comparative tests using the YOLOv5 technique were conducted. The experimental findings show that in ship detecting tasks, EBENet beats the YOLOv5 algorithm, with a mAP50 of 93.6% and FPS of 104.189, performs better in reducing missed detections and false alarms while retaining high detection efficiency. Therefore, EBENet hence has potential for use in a variety of maritime monitoring and safety duties.

The microstructured surfaces are playing an important role in industry. Measuring these surfaces quickly and accurately can provide significant quantitative results for machining process. However, traditional measurement methods and systems cannot meet the requirements of high precision machining. Measured samples are often moved several times in order to achieve the desired result. To address these limitations, a smart measurement system based on deep learning algorithm is established. The whole measurement system is portable and can be employed in many works situation. This smart measurement can offer an effective way of capturing high resolution images. To enhance the accuracy and efficiency of data processing, a deep learning model is applied in this system. This model can be employed to generate disparity after the input of high-resolution images. After the information fusion of disparity and the depth, which is obtained from the depth estimation module, the microstructured surfaces can be reconstructed accurately. This system is inputted with the synthetic data and experimental results show that the measurement uncertainty could reach at a sub-micrometer level.

A linear model is adopted herein that expresses the ptychographic iterative engine (PIE) as a system of linear equations between the object and probe in the frequency domain. And using this linear model, the unique solution of the complex object can be directly determined without the additional iterative calculation. Simultaneously, based on this linear model, the effect of the detector photoelectric parameters on PIE can be characterized by the existence of the unique solution. A series of investigative simulations have been implemented that discuss the effect of the reconstruction with different photoelectric parameters (such as target surface width and pixel size) for PIE. This mathematical model provides a direct method to obtain the underlying physics of PIE and can also be used to predict the accuracy and error in PIE applications with imperfect detector photoelectric parameters.

Starlink plans to provide faster Internet services in most parts of the world, as a space fast Internet communication plan of SpaceX in the United States. However, according to the overall design of the current Starlink system, Starlink satellites may adopt modular development ideas in the future, aiming at the feasibility and potential of Starlink satellite constellations carrying remote sensing payloads, this paper collects and sorts out the development of Starlink satellite constellations and the orbital parameters of some domestic remote sensing satellites and constellations, and proves the feasibility of Starlink satellites carrying remote sensing payloads through comparison between parameters. Secondly, this paper uses STK to simulate and model the Starlink satellite constellation, and at the same time adds available remote sensing sensors to the satellite, and concludes that at least 60 satellites are required for single-orbit Earth observation of the Starlink constellation to achieve the uninterrupted effect, and an imaging simulation is carried out on a building or object on land, and the visibility and sensor coverage effect of the satellite to the target are displayed in two-dimensional and three-dimensional forms. STK's display analysis function was used to visualize the detailed data report results, and finally the potential of Starlink satellite constellation to carry remote sensing payloads was analyzed.

Edge computing has become indispensable in the context of wireless network communication, particularly in scenarios with strained computing resource such as remote areas or areas where ground communication disruptions are prevalent. It significantly enhances the service quality of ground terminal devices. This paper proposes a Space-Air-Ground Integrated Network(SAGIN) edge computing model. However, the limited computational resources pose challenges to crucial aspects such as edge server deployment, edge server computing resource allocation, and offloading strategies in such scenarios, becoming pivotal in boosting network service capabilities. To address this, we explore different deep reinforcement learning algorithms to train the model towards optimizing system objectives. Among them, the Soft-Actor-Critic (SAC) deep reinforcement learning algorithm demonstrates superior applicability to such model problems, improving training effectiveness by approximately 18% compared to the DDPG algorithm (calculated using average reward value). The edge computing offloading technique also serves as a crucial foundation for future edge computing cross-domain interconnections and distributed task collaboration.

Accurate parameter estimation of space target attitude and size with inverse synthetic aperture radar (ISAR) image is a tough task, which plays an important role in analyzing and monitoring space awareness situation. Key point extraction is one of the crucial procedures for parameter estimation. Cross-polarization ISAR data works well in edge structure reservation. Moreover, considering the characteristics of ISAR image, U-net model, which performs well in sample-background-image segmentation, is more suitable for key point extraction. Therefore, a joint estimation method for space target attitude and size is proposed in this work based on polarimetric ISAR images and modified U-net model. The main contribution falls on two parts. Firstly, key point extraction procedure is conducted with modified U-net model, the architecture and loss function of which are modified according to the characteristics of polarimetric ISAR images. Secondly, the attitude and size parameter of space target are jointly estimated based on the extracted key points and ISAR projection relationship. Compared with comparative method, the superiority of the proposed method is validated using simulated data. Quantitatively, the mean estimation error of attitude parameter is 0.88° and that of size parameter is 0.12%.

With the advances in precision manufacturing, optical metrology has played a vital role in inspecting for processing quality. Chromatic confocal displacement sensor (CCDS) is broadly used in optical detection field, which can achieve submicrometer- level resolution and precision. Although CCDS has many advantages, its measurement uncertainty is easily influenced by various factors when detecting distance. Measurement uncertainty is associated with measurement results, which characterizes the dispersion of the values that could reasonably be attributed to the measurand ^[1]. The uncertainty is low when the measurement result is stable and of high quality. This paper provides a systematic analysis on the measurement uncertainty evaluation of CCDS. Firstly, we briefly introduce CCDS’s principle and the algorithm of uncertainty calculation. Then, main sources of uncertainty when measuring distance are analyzed utilizing a commercial CCDS. Three sets of experiments are conducted: different colors, different angles ranging from -20°to 20°, and different roughness. And they were all carried out with different measuring distances ranging from 0.500mm to 11.500mm. Individual standard uncertainty is evaluated for each source based on GUM method ^[2]. For different colors’ surfaces, the trends of values’ distributions are similar. And the maximum is about 0.013μm, appearing at about 3.600mm. For different measuring angles, the distributions are almost symmetrical, but the symmetry is weakening as the distance increases from 0.500mm to 9.000mm. The values are low for different roughness’s surfaces, ranging from 0.003μm to 0.006μm. Finally, the implications of measurement uncertainty caused by these factors are discussed, providing guidance for future experiments and applications.

In order to analyze the influence of servo drives on the dynamic performance of multi-axis coordinated ultra-precision machine tools, this study employs Simulink modeling and simulation of the control system for a domestic ultra-precision machine tool with gas-static spindle, followed by conducting position control experiments. The dynamic response of the spindle under different drives in ultra-precision machine tools is modeled based on the dynamic characteristic equation of the spindle motor. Waveforms of current, torque, and speed response of the spindle motor under different drives are simulated and analyzed. Control laws between the controlled object and the drive system are derived from the analysis of simulation data. Based on this, a dynamic performance testing platform for the spindle in ultra-precision machine tools is established, with the repeatability of positioning accuracy as the dynamic performance parameter. The linear correlation analysis between the experimental data of repeatability of positioning accuracy and the simulation results is conducted to quantitatively evaluate their correlation. Finally, it is determined that the gas-static spindle under the control of a linear amplifier exhibits the best dynamic performance. Moreover, as the PWM frequency increases under the control of PWM-type drives at 100 kHz, 50 kHz, and 16 kHz, the dynamic performance of the spindle also improves. This study provides reference for the selection of drives in the design and selection stage of control systems for ultra-precision machine tools.

In ultrasonic infrared thermography, ultrasonic waves are used to generate heat in a target being tested. The heat causes temperature variations in the target, which can be captured by an infrared camera. By analyzing the thermal patterns, it is possible to identify defects in the target. We propose a two-stage automatic defect recognition method using temporal signals from ultrasonic infrared thermography. First, the temperature rise thermogram is segmented using Otsu’s method to remove most of the noise signals. Second, the heat variation signals are extracted based on the temperature rise thermogram sequences. Then, a deep learning model, termed temporal signal defect identification network (TSDI-Net), is designed to accomplish automatic recognition of defect signals. The TSDI-Net consists of a time-space feature module, a hybrid two stream feature module, a global average pooling module, fully connected layers and a Softmax output layer. To verify the effectiveness of the proposed TSDI-Net, five models in the literature, ACN-LSTM, MACNN, OS-CNN, ResCNN, and XceptionTime, were selected for comparison. Ultrasonic infrared thermography image sequences from 153 components are divided into a training set, a validation set, and a test set with ratios of 75%, 10%, and 15%. Results show that the proposed method outperforms the existing defect recognition deep learning models.

In recent years, with the development of infrared technology, the radiation value of targets can be quantitatively detected through radiation parameter calibration, making it possible for infrared payloads to determine the type of target based on the radiation value, greatly improving the detection ability of infrared payloads. To ensure the quantitative detection accuracy, it is necessary to calibrate the radiation parameters of the infrared load, accurately grasp the inversion coefficient of the infrared load, and ensure the inversion accuracy of the detection data. This article focuses on the urgent need for on orbit radiation calibration of infrared payloads, and conducts research on on orbit calibration sources based on memes technology. Through experimental verification, the on orbit calibration source, as the standard source for on orbit calibration of loads, can provide a stable infrared radiation and has the characteristics of wide temperature range and multiple calibration points, meeting the calibration requirements during the operation of infrared loads. The on orbit calibration source can serve as a spatial quantity reference to provide high quantitative calibration for infrared remote sensing payloads, laying a solid technical foundation for the next step of space infrared payloads and future development of China's infrared satellites.

In semiconductor manufacturing, wafer defect inspection is critical, both in front-end and back-end processes. Despite the presence of conventional techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), and others for inspecting wafer surface defects, these techniques are not sufficient to meet the urgent demands of in-line inspection for wafer fabs. This paper introduces a new method to fast inspect wafer defects utilizing dark-field scattering in conjunction with time delay integration (TDI). In addition, a wafer surface defect extraction algorithm is designed for this method. The comparison of the postprocessing results with images captured by digital microscopy shows that the algorithm can effectively reduce the influence of column fixed pattern noise (CFPN) on the subsequent defect enhancement and can extract the defect signal from the background noise. This method provides a more targeted reference for wafer surface defect inspection and has important application potential in semiconductor manufacturing.

With the development of the new generation of broadband satellite communication systems, which represented by satellite internet, exhibit the demand for flexible switching of access and feeder links to save onboard beam resources, as well as the demand for special users to access onboard payloads through dedicated channels. To meet these demands, the paper proposes a multibeam access link and feeder link integrated spaceborne communication system. This article conducts three integrated designs: the integrated design of the system protocol, the integrated design of the onboard antenna, and the integrated design of the onboard processor. It also describes two key processes: beam mode switching and data diversion of the onboard gNB (Next generation node B). The designed communication system has three advantages. Firstly, it achieves dynamic multiplexing of satellite beam resources. Secondly, it achieves efficient utilization of onboard equipment. And thirdly, it achieves flexible and secure networking for specific types of users.

The design method of free-form lens is very liberal , which can simplify the optical components and support structures required in the system and make the overall optical space more compact. So the free-form surface has a wide range of applications in imaging and non-imaging optics. In this paper, a improved optimization method for designing of free-form lens for light-emitting diode (LED) light distribution was proposed. Based on the lens matching curve obtained by weighted superposition, feedback optimization method was used to further improve the optimization possibility of lens. The weight factors of each surface are optimized by particle swarm optimization algorithm to minimize the evaluation function based on illuminance uniformity of the target surface. The illuminance uniformity on the target plane is optimized from 72.8% to 91.7% start form initial structure. The results show that the proposed algorithm has the advantages of high optimization efficiency and good optimization effect.

In night vision technology, due to the passive technology's unidirectional and high concealment advantages, it has been paid attention to, among which the low light level night vision instrument has obtained rapid development. With the improvement of the performance of low light level night vision instrument, it is very important to test the index of high resolution and wide field of view to ensure the comprehensive performance of night vision instrument. In China, in the development of low-light night vision instrument, many standard equipment in the laboratory are used to piece together, or the equipment developed is a general low-light test equipment, and a special and standard low-light night vision instrument tester has not been developed. In this study, a comprehensive measurement method of night vision is proposed. Through the design of resolution, contrast test module, field of view Angle test module and data acquisition system, a complete and multi-functional test system is formed, in which the system aperture is greater than 110mm, the resolution test range is 0.06~2.6mrad, and the field of view Angle measurement range is ±25°. The light source brightness ranges from 1.6×10^-5 to 5×10^-3 cd/cm². Through the docking verification with the night vision instrument, the low light level night vision instrument tester has realized the accurate measurement of the low light level night vision instrument's resolution, field Angle, contrast and other indicators, which provides a guarantee for the performance of the low light level night vision instrument.

Optomechanical system assembly is a complex process and serves as the final stage in implementing a system, playing a crucial role in determining the performance indicators of the Optomechanical system. The performance of the Optomechanical system is mainly affected by two factors: surface shape errors of optical elements and alignment errors of components, both of which are related to the assembly process. Stress is one of the main causes of surface shape errors in optical elements. During assembly, the coupling stress can cause changes in the shape of optical elements. These changes may result in surface shape deviations from the design requirements, thereby affecting the system's performance. Alignment errors of parts and components can cause assembly errors such as misalignment, tilt, and optical spacing in the optical system. These errors can have adverse effects on the optical performance of the system. The Optomechanical system assembly errors mainly include component-level assembly errors and system-level assembly errors. To accurately analyze and estimate the assembly errors of the Optomechanical system, a small displacement torsor theory and the technique of spatial pose transformation matrix have been used to construct an error analysis model for the Optomechanical system. These models can assist engineers in predicting and controlling assembly errors, improving the performance of the Optomechanical system, and guiding the design and production of the Optomechanical system.

The key challenge in fabricating large departure aspheric surfaces is how to control the mid spatial frequency (MSF) errors. There are many ways to suppress the MSF errors such as changing the polishing path of the tool, using a smaller polishing tool spot, and modifying polishing parameters. Smoothing is a convenient and efficient way to directly correct MSF errors. During the smoothing process, the best-fit sphere is usually used to model the aspheric surfaces. It has a few impacts on the final quality of surfaces, but with the increase of the departure of aspheric surfaces, the curvature of large departure aspheric surfaces changes rapidly in some areas leading to the final quality not meeting the expectations since the pitch pad completely not fits with the surface in smoothing polishing. To solve this problem, an improved control with a threeaxis linked computerized numerical control machine is proposed. This method is based on matching the direction between the polishing force and the normal of surface and making the contact area between the pad and surface in the position we expect. Two large departure aspheric surfaces with the same shape were used to verify. The surface MSF errors using the unimproved method reduced from 56nm to 27nm for 9h smoothing while the surface MSF errors using the improved method reduced from 81nm to 17nm for 8h smoothing. The convergence of the improved method increased by 27%.

The transmitted wavefront mid-spatial-frequency(MSF) errors of spherical lens has a great influence on the quality of the transmitted beam. Aiming at the problems of poor convergence precision and low convergence efficiency in mid-spatial frequency errors polishing of large square spherical lenses, this paper proposes a mid-spatial-frequency errors correction technology by using full-aperture rigid polishing combined with numerically controlled sub-aperture smooth polishing. In the full-aperture polishing stage, the surface shape distribution that is conducive to subsequent sub-aperture polishing is obtained through radius compensation technology to reduce the sudden change of surface shape in the corner area of the component. The more rigid polishing pad is used to smooth the whole surface then, so that the component has better MSF errors condition before the sub-aperture high-precision surface correction. In the stage of small tool CNC polishing, the transmission structure and mass distribution of the polishing disc are optimized, and the ideal transmission characteristics and size parameters of the polishing disc are obtained through mechanical simulation analysis to reduce the overturning moment of the polishing disc when the direction changes suddenly. This optimization also improves the pressure distribution of the polishing interface. Stability, a flexible polishing disc combined with a high dispersion polishing slurry is used to correct the surface errors. The concentration of the polishing slurry is optimized and the supply method is well changed. So when the surface shape errors convergence process is more efficient and controllable, it will not cause the deterioration of the MSF errors. The smooth tool is applied in the last stage with reducing the temperature change of the polishing interface. All these measures are aimed to increase the stability of smooth polishing and to achieve high-efficiency, high-precision and stable convergence of MSF errors. The experimental verification was carried out on four square spherical lenses with a size of 440mm×440mm. The final PSD1:RMS values have all reached within 1.8nm. Additionally the overall processing time has been greatly shortened.

Laser-induced graphene (LIG) is a novel strategy for preparing graphene by taking advantage of the sufficient photothermal and photochemical reactions to develop nanomaterials with good physical and chemical properties. Recently, considerable research is devoted to efficiently prepare graphene antimicrobial devices taking advantage of the size and shape customizability of laser processing. However, the relationship between quantification of reduction rate and graphene nanostructure porosity has not been systematically studied. Hence, in this paper we applied a simple and efficient method to prepare graphene antibacterial paper by in situ reduction of polyimide in one step by exploiting the absorption of laser photon energy by the chemical bonds in the precursor material. And we further clarified the antibacterial mechanism of laser-induced graphene paper (LIGP) with the aim of achieving better antimicrobial performance by microstructure modulation through laser processing parameters. Microscopic analyses and colony counting assay were employed to demonstrate the antibacterial effect of graphene. Notably, LIGP at 1.0W laser power (LIGP-1.0W) exhibits the most significant bactericidal rate (94.1% for E. coli and 97.5% for S. aureus) attributed to its extremely high specific surface area (SSA, 189.3 m2 /g), the unique tunable nonporous structure increases extensive contact area with bacteria to provide more sites for capturing bacteria, which was further verified by oxidative stress-related mechanism. The prepared LIGP device can be used to prevent aluminum biocorrosion on material surface and used as antibacterial devices which can be customized to match diverse application scenarios.

The white light interferometry technique can measure the three-dimensional topography of ultra-precise complex surface with sub-nanometer resolution and precision, and has been widely concerned by academia and industry since it was proposed. The measurement range of white light interferometry technology is usually limited by the size of the optical field of view of the system, and the surface of the measured object can only be measured within the limited range of the camera's single imaging. In order to obtain the microscopic surface topography with a larger field of view, it is usually necessary to conduct stitching measurement. In this paper, a measurement method of aperture stitching of white light interferometry based on feature extraction is presented. The first step is subaperture partitioning and data preprocessing. The second step is feature extraction. The feature points are extracted by the Speeded-Up Robust Features (SURF) algorithm. The third step is to identify and filter wrong match points in the feature extraction algorithm using the Random Sample Consensus (RANSAC) algorithm. The fourth step is to use the improved Iterative Closest Point (ICP) algorithm to accurately register the point cloud, and perform data fusion in the overlapping region to complete the reconstruction of the microscopic three-dimensional surface topography. This method is used to measure the microstructure of quartz vibratory beam accelerometer. The experimental results show that the proposed algorithm has a faster speed than the traditional algorithm while maintaining high precision.

Currently, high-resolution mask is mainly fabricated by electron-beam lithography (EBL), with which the resist heating by the electron-beam is unavoidable. It has been reported that the local temperature can berise up to 300 °C when a photomask is fabricated by a variable shaped beam (VSB) EBL¹, which may cause significant critical dimension (CD) variation if the heating effect is uncorrected. However, the heating effect in mask fabrication with Gaussian beam EBL has been rarely studied. It is important to understand the heating effect in the fabrication process of high-resolution photomask, so that necessary correction can be made to reduce the CD variation. In this paper, we report our study of resist heating in mask fabrication with Gaussian EBL system. A software TEMPATION (Temperature Simulation) was used for the simulation. In the simulation, the EBL system gaussian beam system with energy of 125 keV and current of 1 nA and 10 nA. Quartz and sapphire with thickness of 6.35 mm were used as substrates for the mask and simulated separately. Both the quartz and sapphire substrates were coated with 40 nm Cr and 100 nm e-beam resist. The simulations have shown that the temperature rise is about 2 °C for thequartz substrate and 0.6 °C for the sapphire substrates. The temperature rise by the Gaussian beam EBL is much lower than that of VSB reported (300 °C) due to the much lower beam current of the Gaussian beam than that of a VSB system.

The primary mirror system is the key component of the high-precision optical system, and the surface accuracy of the primary mirror determines the imaging quality of the whole system. When the lightweight mirror is affected by its own weight, support mode, load and temperature, the surface shape accuracy of the primary mirror will be changed, and the assembly mode of the primary mirror is an important factor to ensure the surface shape accuracy of the primary mirror. There are usually three types of assembly modes for the primary mirror: peripheral support, central support and back support.

In this paper, the supporting mode of 650mm lightweight mirror is studied, and the surface shape of the mirror is analyzed under two supporting modes (center support and back support) when the elevation of the mirror is between 0 ° and 60 °, which is affected by its own weight. Firstly, the primary mirror is modeled based on CAD; then, the CAE mesh is generated according to the CAD model with different support modes, and the structural deformation of the primary mirror under different working conditions is obtained by solving the structure of the primary mirror under different working conditions; finally, the mesh data of CAE analysis is extracted, and the mesh data is subjected to polynomial fitting to obtain the deformation of the secondary mirror in different working conditions and States.

Based on the method of simulation analysis, this paper adopts a variety of simulation tools, including CAD, CAE, multidisciplinary fitting analysis software and so on. The deformation of the primary mirror under different working conditions and different support modes is obtained. When the 650 mm lightweight mirror is supported on the back, the surface shape change does not exceed RMS 0. 01 λ at different elevation angles. For the center support, the surface shape change is RMS 0. 004 λ to RMS 0. 12 λ in the elevation angle range of 0 ° to 60 °. This supporting mode has a great influence on the surface shape. Based on the simulation analysis data, the back support is used for the assembly of the 650 mm lightweight mirror, and the center support is not suitable for the assembly of the mirror.

Research of imaging spectrometer is of great significance to improve the applicability and accuracy of the alternative calibration of remote sensor in orbit. According to the requirements of the imaging spectrometer, the structure of the imaging spectrometer is presented by combining the off-axis three-trans front optical system and the beam splitting system based on the convex grating. The design of the optical system of the imaging spectrometer with compact structure, small volume, high spectral resolution and good imaging quality is realized by the combination of the two, which meets the design requirements of the imaging spectrometer optical system. The operating band of the optical system covers 400 ~ 1000nm, the F-number is 3.3, the field of view is 11°. In order to verify whether the imaging spectrometer meets the design specifications, it is necessary to carry out laboratory assembly and testing of the instrument. Due to the influence of processing technology, there will be some processing errors in the processing of mechanical structures and optical components. In order to make the installation of each component as close to the ideal position as possible, reduce the influence of optical path offset on the optical system, and enable the detector to accurately detect the spectral information of the target, it is necessary to install and debug the spectrometer system to ensure the measurement accuracy of the instrument. According to the test results, the installation state of the optical slit and off-axis triple reaction system is continuously optimized until the best state is achieved. This research provides the technical support for the development of imaging spectrometer, and lays a foundation for the on-orbit radiometric calibration of remote sensor based on imaging spectrometer.

In this paper, we present a method for measuring the focal length of large aperture lenses using reflective computergenerated hologram (CGH). The CGH is designed to emulate the properties of a large aperture retrosphere through diffraction when performing null test of a lens with an interferometer. To validate this test approach, we designed and fabricated a 450 mm × 450 mm reflective CGH specifically for testing the 440 mm × 440 mm spatial filter lenses with a focal length of 31984.222 mm (@ 632.8 nm). Experiments and error analysis were carried out. The results show that the CGH test approach features high accuracy and good repeatability.

The conventional three-dimensional (3D) reconstruction simplifies the camera into a pinhole camera model. The simplified model may be limited by the change of the optical center when the working distance deviates from the calibration distance. A three-dimensional reconstruction method of defocused images based on optical system analysis was proposed. Firstly, an optical system model for the imaging system to be calibrated was established on a low number of image captures. Then according to the camera parameters calculated by calibrations under the proposed model, the relationship between the working distance and the camera parameters in depth of field was quantified. The camera parameters of different working positions were obtained in a single calibration, without repeated calibrations at different positions. The effectiveness of the proposed model in dealing with defocusing 3D reconstruction is proved by experiments.

R-C optical systems have been widely used in long focal length imaging and long-distance detection fields such as aerospace, remote sensing, exploration, and space optical communication. However, the significant wavefront aberration in the edge fields of R-C optical system always restrict the imaging system in a small field of view. In this paper, the improved R-C optical system is composed of two reflective mirrors as well as three refractive elements, which can correct off-axis aberrations in large fields of view, enable the large field of view imaging. For the high accuracy assembly, optical centering assembling technology based on optical imaging principle is applied to ensure the coaxiality between the optical axis of optical element and the rotation axis of corresponding machine part. And the reverse optimization method is carried out to compensated the wavefront aberration introduced by misalignment errors. Finally, the testing optimization result of system wavefront aberration with RMS value of center of view is 0.045λ (λ=0.6328nm), and the RMS value of off-axis field better than 0.08λ can be achieved.

Satellite communication, as the key component of the future 6G&7G communication network, is the main means of realize anytime and anywhere communication. Traditional satellite communication requires dedicated SatCom terminal as WIFI hotspot , or handheld SatCorn terminal for personal communication, using private protocol resulting in expensive prices and rarely used for mass consumer. With the development of LEO constellation Satcom, the satellite system represented by SpaceX and AST that use smartphones to communications with satellite have made it possible to achieve anytime and anywhere communication for mass consumer. This paper summarizes the current development status of satellite-to-smartphone system, then conducts research and analysis on key technologies of satellite networks, explores potential technology roadmap, and finally puts forward suggestions for the future development of satellite-tosmartphone for LEO satellite constellation network.

The removal function in machining is not an ideal impulse function, and the material removal at any point on the workpiece is a superposition of the removal at that point from the distribution of removal at surrounding points. When the residence time suddenly jumped to zero at the edge, the removal function and the residence time convolution results will gradually decrease at the edge, the removal matrix at the edge of the formation of the "collapse", after many convolution iterations, the edge of the face shape of the error convergence rate is lower than the other positions, resulting in edge effects. This paper firstly put forward an iterative algorithm based on the residence time of the cylindrical projection, and then analyze the edge effect in the iterative algorithm, and put forward two methods to suppress the edge effect, and select different removal functions and the form error on the algorithm to carry on the simulation calculation. Finally, the results of machining of mold #54 verifies the effective suppression of edge effect error by the method in this paper.

EP satellite is a scientific exploration satellite for time-domain astronomy and high-energy astrophysics, its function is to carry out high-energy transitory celestial body survey with the highest sensitivity in the soft X-ray band. EP will be equipped with two groups of x-rays focusing mirrors (each group contains 54 Wolter-I mirrors). An X-ray focusing mirror is used to collect X-ray radiation in the universe, and is the core component of an X-ray astronomical satellite observation payload. The current X-ray focusing mirrors are derived from the Wolter-I reflector, and the light is focused through the inner surface. The inner reflection surface is an optical free-form surface connected by parabolic and hyperbolic surfaces. Many conventional measurement methods are not applicable and difficult to measure. High precision contact measurement is easy to scratch the mirror surface, Therefore, noncontact measurement must be used. In this paper, we develop two non-contact surface precision measurement devices are developed to solve the problem of difficult measurement of the inner reflection surface of the X-ray focusing mirror. One is a rapid measurement device based on the principle of optical star measurement method, The other is to measure the mirror inner surface by a single point scan measurement, the optical triangulation method is selected as the principle of the measurement device. We then verified the measurement accuracy of the mirrors with a precision visible light test system. In order to further verify the measurement accuracy of the focusing mirrors, X-ray testing of the focusing mirror was carried out at the 100-meter vacuum X-ray calibration facility of the Institute of High Energy Physics, Chinese Academy of Sciences. The X-ray measurement results are better than the project index requirements.

The field of space imaging optics is committed to developing large field of view, large aperture, and unobstructed space optical imaging systems. The structure of optical systems has evolved from coaxial optical systems to off axis optical systems. In order to reduce the difficulty of installation and improve the efficiency of off-axis multi-reflection optical systems, the paper studies the precision installation and adjustment process method of off-axis multi-reflection optical systems on account of the principles of spherical autocollimation and spatial coordinate measurement. Establish global coordinate system based on the optical design and processing benchmark of the off-axis multi-reflection optical system, use a laser tracker and auto-collimation theodolite to accurately locate the elevation and azimuth angles of the reflector, and adjust the optical target ball to the theoretical center point position and align with PSM. Remove the target ball. If the actual center of the spherical mirror is not in the theoretical coordinate position, the position deviation and sharpness between the reflection image point and the point light source can be monitored in real-time, and the posture of the mirror can be precisely adjusted to make its reflection image point coincide with PSM. This process method can achieve high-precision and high-efficiency adjustment of the off-axis multi-reflection optical system. The assembly results show that the spatial coordinate position error between the mirrors in the off-axis multi-reflection optical system is better than 15μm through high-precision spatial coordinate positioning, reference transfer and precision measurement. The angle error is better than 30″, and the center field of view wave aberration RMS=0.034λ@632.8nm, meeting the design specifications.

With the rapid development of large field of view, large aperture and unobstructed space optical imaging system, the optical imaging system structure has developed from aspherical coaxial and off-axis free surface off-axis. Free surface is applied to multi reflective Off-axis optical system to balance the sharply increased off-axis aberration. Because the free-form surface does not have symmetry, the full free-form surface multi reflective Off-axis optical system has lost the rotational symmetry of the traditional optical system in structure, resulting in more degrees of freedom in the installation and adjustment of the full free-form surface multi reflective Off-axis optical system, the relationship between optical axes of various optical elements is complex, the system integration is more difficult, and the installation and adjustment process is difficult to monitor. Based on this, the paper proposes a precise alignment process method of the full free-form surface multi reflection Off-axis optical system. The space global coordinate system is established through the space coordinate measurement equipment, and the precise attitude of each reflector is monitored by combining the self-aligning Theodolite and cube mirror, and the reference transfer space position is measured by using the self-aligning microscope and the measurement target ball. he engineering project verification shows that this assembly and adjustment process method realizes the unification of the design, processing and assembly and adjustment benchmark of the full free-form surface multi reflection Off-axis optical system, has strong operability, reduces the difficulty of assembly and integration, and the comprehensive measurement accuracy is better than 0.01 mm. The wave aberration RMS of the final refrigeration relay long wave infrared camera system is better than 0.45 λ @ 632.8nm, meeting the design specifications.

Driven by increasingly frequent and diversified world trade, it is of great significance to realize real-time wide-coverage monitoring of shipping containers, as well as low-latency and low-energy transmission. Under the background of supporting and developing the application of low-orbit satellite Internet of Things (IoT) business, this paper considers installing wireless sensors on the side of shipping containers and monitoring the data and status of shipping containers in real time through low-orbit satellites. This paper designs three algorithms: The LoRa underlying adaptive transmission optimization algorithm including the initial allocation of the underlying transmission and the adaptive spread spectrum factor fairness optimization strategy, the Internet of Things terminal self-organizing network networking algorithm based on the Low Energy Adaptive Clustering Hierarchy(LEACH) protocol to improve the cluster head election strategy, and Internet of Things terminal self-organizing network routing algorithm using Bellman-Ford to achieve minimum cost routing selection. In the set simulation environment, the average coverage rate of the traditional LEACH protocol clustering is 0.8274, while the improved algorithm reaches 0.9701. The simulation results show that the proposed scheme is superior to the existing traditional mechanism, and can effectively realize the Internet of Things terminal self-organizing network with dynamic topology, wide coverage and high data volume transmission.

Off-axis optical systems do not have rotational symmetry and cannot be optically centering turned by CNC machine to eliminate component tilt errors, so they are more difficult to be aligned than the coaxial optical systems. In this paper, the computer-aided alignment technology is carried out for a four-mirror off-axis reflective optical system. Firstly, aberration characteristic analysis is performed to obtain the relationship between the degrees of freedom for mirrors and the wavefront coefficients. Using the results of the above analysis, a segmental alignment method is proposed. Finally, the article has completed the experimental verification for the optical system alignment. The wavefront quality meets the requirement which verifies the validity of the theoretical analysis. The research results can provide effective solutions for the alignment of various off-axis optical systems.

AISM telescope is the abbreviation of Accurate Infrared Magnetic System. This telescope is the first mid infrared system internationally used for observing the solar magnetic field. The system is an off-axis telescope with an aperture of 1 meter. The optical path is complex and the light is folded over a long distance through multiple flat and aspheric mirrors and coupled with mechanical rotation axis. The conventional alignment methods cannot be applied. This paper describes the methods for reserving assembly reference for each module and the system optical axis consistency adjustment method. The method has been verified through actual experiment and can achieve high precision.

This paper investigates a method for measuring and calibrating the mirror attitude, tilt monitoring system, and compensation lens in a diffraction camera. Firstly, a measurement network is established by installing a reference prism and a theodolite on the load-bearing plate, enabling the overall measurement of the position of the mirror relative to the camera. Then, by changing the attitude of the mirror and recording the changes in the detector point coordinates, the relationship between the direction angle of the mirror and the detector point coordinates is calculated. Then, by adjusting the compensation lens in its local coordinate system, the relationship between the compensation lens and the detector point coordinates is obtained. Finally, by substituting the above matrix into the conversion matrix formula, the conversion matrix between the direction angle of the secondary mirror and the compensation lens translation is obtained, thereby completing the calibration of the attitude. This method can directly drive the compensation lens according to the change in the position of the mirror, ensuring the imaging quality of the camera.

X-ray mirrors play a critical role in transmitting and focusing beams in advanced light source devices like synchrotron radiation (SR) and free electron laser (FEL) light sources. The Root-Mean-Square (RMS) value of surface shape accuracy required for these mirrors is typically sub-micro radian/sub-nanometer, and their aperture can be hundreds of millimeters or even meters. To achieve this accuracy, deterministic figuring is required and surface figure error is the premise. Interferometric stitching test is commonly utilized. However, interferometric test obtains the surface figure error relative to the reference surface. To obtain the absolute surface figure error of X-ray mirrors, it is crucial to obtain the surface figure error of the reference surface before or during stitching measurement and separate it from the stitching result. To achieve this, a reference surface self-calibration interferometric stitching algorithm based on Legendre polynomial fitting is reported. The algorithm fits the reference surface by orthogonal Legendre polynomials in the rectangular domain, and the polynomial coefficients are expressed as interlocking terms in the stitching algorithm. The fitting coefficients are optimized and fitted together with the free compensation terms, i. e. the translation and tilt terms. The paper established the theoretical model of the algorithm and conducted simulations on an X-ray mirror with a length of 300 mm. A two dimensional stitching interferometry device was built. An X-ray mirror with a length of 300 mm was tested utilizing the proposed method. The short-term repeatability was preliminarily analyzed.

Ultra precision turning technology is widely used in the manufacturing of optical precision components due to its excellent machining accuracy and production efficiency. In the actual turning process, various types of vibrations are superimposed and manifested as relative vibrations between the tool and the workpiece, resulting in specific shape texture features on the surface of the workpiece, seriously affecting the surface quality of the workpiece and reducing its efficiency. This article analyzes the impact of unfiltered low-frequency vibration in the ultra precision machining process environment on the machined surface morphology, achieving vibration error tracing based on workpiece surface morphology data analysis and texture features, and further improving the surface quality of ultra precision turning workpieces. A simulation model for ultra precision turning surface morphology was established based on the principle of tool contour mapping, taking into account the relative vibration in the circumferential, axial, and radial directions between the tool and the workpiece. Based on the deterministic and random factors obtained, the morphology prediction simulation was carried out in the model. Based on the comparative experimental method, single factor experimental method, and result oriented principle, the effect of different cutting parameters on the surface quality of the workpiece under the influence of low-frequency vibration was analyzed. The simulation results were compared with the actual surface morphology, and it was found that the simulation results had consistent layout rules with the measured morphology images. This study provides a reference for the establishment of ultra precision cutting models under external low-frequency forced vibration.

In this paper, a white light interference detection device is mainly established to measure the surface roughness of the focusing lens mold to test whether the surface roughness of the mold meets the requirements of making lenses. The model is established by SolidWorks software, the static and dynamic analysis of the machine tool model is carried out by Ansys Workbench software, and then the measurement experiment of the surface roughness of the focusing mirror mold is carried out.

For most of the current white light interferometer mechanical structure are vertical structure and the size of the inspected parts have limitations, this paper mainly uses white light vertical scanning measurement technology to develop the measurement system for in-situ measurement of ultra-precision machined parts surface three-dimensional topography, white light interferometer mechanical structure design and machine tool integration, to carry out the design of the mechanical structure of the white light interferometer and the integration of the machine tool, and the completion of the measurement system to build a physical example of the system to test the verification of the reliability of the system.