As a new type of zoom element, the liquid lens has the characteristics of fast response, no wear, and small size, which brings new ideas to the design of the zoom system. This paper proposes a liquid-solid composite zoom optical system without mechanical movement. In the system, two liquid lenses are used as the zoom group and the compensation group of the system, so that the image plane position is always stable during the zooming process of the system. Based on the Gaussian theory, the relationship between the focal length of the system and the focal length of a single liquid lens is derived, and a multi-layer traversal algorithm is proposed to solve the initial structure parameters of the system. The optimized design of the zoom optical system and image quality analysis was completed by using ZEMAX software. The results show that the system can achieve continuous zoom in the range of 20-60mm, the zoom ratio of the system is 3, and the image quality is good. The modulation transfer function of each focal length of the zoom system at a spatial frequency of 50lp/mm is greater than 0.2, and the RMS value of wave aberration is greater than 0.3 times the wavelength of the probe light, which meets the design requirements.
In order to solve the problem that the extra removal layer and the motion characteristics of the machine tool are difficult to meet the processing requirements of ion beam figuring, an ion beam figuring method based on new controllable ion source is proposed. By changing the working parameters of the ion optical system, the timing and duration of ion beam extraction are controlled in real time. The influence law of the machine tool motion acceleration in the process is analyzed theoretically, and then a new ion beam figuring method is proposed for the lack of dynamic performance. By adjusting the working parameters of the ion source developed by ourselves, the pulse duty ratio is continuously adjustable from 0 to 100% , and the pulse frequency is continuously adjustable from 1 to 1000 Hz. The sample is Φ100 mm monocrystalline silicon plane mirror. Firstly, the long-time stability of the new ion source was verified by line- scanning experiments, and then the error of 14.5 mm wavelength was etched with the axis of motion at a constant speed. The results show that the technology can make up for the lack of motion acceleration and avoid the extra removal layer, and have a wide range of potential applications in high precision quality adjustment, special surface treatment and so on. It is expected to promote the progress of ultra-precision machining technology.
Ion beam figuring has the advantages of non-contact, high certainty, and removal function’s long-term stability. It is the primary processing method of ultra-high precision optical elements such as lithography objective lens. In general, the IBF process does not require high motion precision of the moving mechanism. However, when the shape of the optical components changes from a plane to a curved surface and the RMS value of the surface accuracy is better than 0.3nm, the influence of the motion accuracy cannot be ignored. The paper focuses on the influence mechanism of IBF equipment’s motion accuracy on the shape of removal function, removal rate, and other essential parameters under the three-axis figuring mode of curved surface elements. We have discussed the sub-nanometer precision generation requirements of curved elements for removal function positioning accuracy and motion accuracy of polishing equipment. The feasibility of ion beam triaxial machining for the sub-nanometer precision generation of curved optical elements is demonstrated by analysis and calculation. The results show that under the condition of ensuring the micron motion accuracy, the three-axis ion beam figuring equipment can also process the curved surface’s surface to the ultra-high precision that the RMS value is better than 0.3nm. Still, it is difficult to achieve the machining goal only by improving the motion precision of the machine tool’s motion axis, so it is necessary to control the components’ initial profile error.
Mechanical vibration has a great influence on the design of mechanical system. Mechanical systems often need to design a reasonable vibration damping mechanism to maintain the normal operation of the mechanism the compliant mechanism has good guiding accuracy and cushioning stiffness. Through the analysis of the actual cushioning problem and the structural topology of the existing traditional, compliant unit, this paper selects Roberts four-bar mechanism as the primary design scheme of the respectful team, obtains the basic configuration of the extended compliant unit through the stroke expansion deformation of the selected mechanism, and carries out the stiffness modeling and analysis of the basic configuration unit of the compliant mechanism, to obtain the stiffness performance. Finally, the structural and element verification optimization is carried out according to the designed compliant mechanism. The central performance verification is carried out through FEA (finite element analysis) simulation. The results show that the designed mechanism has good stiffness buffer performance and meets the design requirements.
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