The paper is devoted to the analysis and review of optical resonance gyroscopes on low-coherence radiation sources. The main advantages of using low-coherence radiation sources in optical resonance gyroscopes are considered. The circuit design options for their implementation developed to date, their operating principle, achieved characteristics, common problems of such gyroscopes and methods for solving them are analyzed.
The condition and concept of confocality for ring resonators are considered. The advantages and limitations of such a design and its prospects for application in passive optical gyros are considered. It is also shown that earlier proposed scheme with toroidal reflecting surfaces can be substituted by the ring cavity with the internal axially symmetrical lens (GRIN-lens).
The paper investigates the resonances of reflection (transmission) of a structure consisting of two optically coupled subwavelength silicon rectangular diffraction gratings, separated by a layer of optically transparent dielectric. The considered structure combines gain, loss and optical coupling coefficient of the periodic structure to effectively operate in parity-time symmetry mode. The spectral characteristics of the resonant reflection (transmission) of the metastructure are analyzed both in PT-symmetry mode and when switching the system to broken PT-symmetry mode. The advantages and disadvantages of using optical parity-time symmetry to control resonant reflection (transmission) for TM- and TEpolarized light incidence are demonstrated. It is shown that changing the relative arrangement of the gain and loss gratings with respect to the incident signal field significantly affects the ratio of transmission and reflection coefficients. All results are obtained considering the dispersion of the materials used.
The use of metasurfaces as scales of optical rotation angle sensors (encoders) makes it possible to reduce their overall dimensions by several orders of magnitude. The paper briefly discusses one of the possible options for implementing a rotation angle sensor with a scale from a metasurface. As a scale it is proposed to use a metasurface – a dielectric onedimensional subwavelength array designed to operate in the infrared spectral range (at a wavelength of 1.5 microns). By the finite element method, a prototype of an optical angular scale from a metasurface has been developed by computer modeling. The results of an experimental study of a prototype of an optical angular scale from a metasurface are presented. The metasurface was made of tantalum oxide and deposited on a quartz glass substrate. For the convenience of the study, the size of the scales was set to 400 × 400 microns, but if necessary, it can be reduced by more than an order of magnitude. The dependences of the transmission spectra of the prototype scale on its rotation angle are experimentally investigated.
The purpose of this study is to develop an optical inclination angle sensor using a metasurface as a scale. We propose to use the dependence of the reflection or transmission spectrum of the metasurface on the direction of light incident on it to measure the inclination angle. The disadvantages of this approach when using the simplest completely passive metasurfaces are considered. In particular, the use of bulky devices to scan the spectrum of the structure. As an alternative, the possibility of using metasurfaces with parity-time-symmetry properties to measure the inclination angle is proposed and investigated. Then no spectrum scanning of the metasurface is required to perform inclination angle measurements. As an example, a metastructure formed by two optically coupled subwavelength diffraction gratings (one of which is characterized by losses, and the other by gain) with a rectangular stroke profile is considered. The study is based on computer modeling by the finite element method.
This article describes an experimental study of the optical vortex generation with the use of light that was reflected from the combination of two cube-corner reflectors (retroreflectors) and its analysis in far field. The main goal of our research was to confirm the theoretical data from the article. Shearing interferometer was used for optical vortex detection and analysis. Our previous studies were focused on cases with linear polarization forming a polarization vortex. This time we were using light circular polarization to produce an optical vortex with m=2.
The main approaches to the construction of optical gyroscopes based on passive ring resonators are analyzed and reviewed. The history of the development of the first prototypes of such gyroscopes, which were in the focus of attention in the late 70s as a part of trials of vanishing the lock-in zone of laser gyroscopes, is considered. Modern studies of optical gyroscopes based on passive ring resonators are performed due to the trend towards the miniaturization of optical gyroscopes. The main disadvantages and problems of such gyroscopes as well as possible solutions are described. In particular, the results of research performed by the authors of the article are presented. The main types of gyroscope sensitive elements and their achievable characteristics are considered
The condition and concept of confocality for ring resonators is considered. The results of the development of a compact (meridional cross-sectional area less than 2 cm2) monoblock ring resonator designed to operate as a sensitive element of an optical gyroscope are presented. A prototype batch of these resonators were studied experimentally. In particular, the shape of the reflecting surfaces of ring confocal resonators and their mutual orientation were measured. The problem of stable input and output of light from monoblock ring confocal resonators and the possibility of their integration into the design of an optical resonator gyroscope are also considered.
A sample of an optical monoblock ring confocal resonator is analyzed. It is a reflective prism made of S-TIH optical glass with four working surfaces located at the vertices of a square. One of the reflective surfaces is used to input and output radiation from the resonator by violating the effect of total internal reflection with the help of an auxiliary reflective prism. The spectral and other optical characteristics of a sample of an optical monoblock ring confocal resonator are studied. Its advantages over other types of optical ring resonators and the prospects for its application in optical sensors, in particular, in optical gyroscopes, are also considered.
The work is devoted to the analysis of the accuracy characteristics of rotation angle sensors using angular scales from nanostructured metasurfaces. The principle of their operation is based on the dependence of the frequency response of metasurfaces on the orientation of the incident light polarization plane. The influence of the noise characteristic of angle sensors on the measurement result is considered. It is shown that for the sensors considered in the work, it might be on the order of units of arc seconds. The influence on the accuracy characteristics of misalignments of the angular scale and thermal effects that the sensor may experience during operation is analyzed. Recommendations to reduce the influence of parasitic effects and further improve the accuracy characteristics are given.
The article describes an optical response of metastructure consisted of two optically coupled resonant subwavelength rectangular - profile diffraction gratings, between which a layer of optically transparent dielectric was placed. The features of optical resonance transmittance and reflectance for optical PT-symmetry mode was numerical investigated and some advantages of using optical PT-symmetry for resonance transmittance (reflectance) improving was demonstrated. The spectral characteristics of the metastructure change when the pumping level changes and when the system switches from the optical parity-time-symmetry mode to the broken parity-time-symmetry mode were analyzed too.
A sample of a ring confocal resonator designed to operate as a sensitive element of an optical resonator gyroscope is studied. The sample has a monoblock design - the resonator is a single block (prism) with reflective surfaces operating on the effect of total internal reflection. The optical contour of the resonator has the shape of a square with a side length of 10 mm and is formed by four reflective surfaces. Three reflecting surfaces are flat, and one is toroidal with curvature radii in the meridional and sagittal planes that satisfy the confocality condition. The resonator is designed to operate at wavelengths of about 1.55 μm. The advantages of using a of a ring confocal resonator as a sensitive element of an optical resonator gyroscope are analyzed. In particular, it is shown that the reduction of the angular velocity measurement error caused by the optical Kerr effect becomes possible (compared to the use of a waveguide cavity and a whispering gallery mode cavity). The resistance of the system to external influences also improves.
A new type of optical resonator gyroscopes based on systems with parity-time-symmetry properties is considered. A system with parity-time-symmetry properties is composed of two direct coupled waveguides, one of which is characterized by losses, and the second one – by amplification, and a passive ring resonator connected to them. The influence of the characteristics of the parity-time-symmetry system on the optical resonator gyroscope parameters is investigated. Attention is paid to the influence of the gain, losses and coupling coefficients of the waveguides that make up the system with the parity-time-symmetry properties. The influence of the gain coefficient instability caused by a change in the pumping power on the angular velocity measurement results is also considered. The advantages and disadvantages of this approach are compared with a conventional optical resonator gyroscope. The main advantage of using systems with parity-timesymmetry properties is the increase of accuracy of registration of passive ring resonator eigenfrequencies by several orders of magnitude and, as a result, the maximum sensitivity to angular velocity.
This article describes an experimental study of the optical vortex formation using beams reflected from a combination of two cube-corner reflectors with a special interference phase-shifting coating. As predicted earlier, if arranged properly, these cube-corner reflectors create a spatial polarization structure, that can be called an optical vortex, since the plane of oscillations of thе vector E rotates with azimuth variation in the transverse plane. Our previous studies concluded that such configuration works as intended, however only near-field images were obtained. This time we preset experimental results in the far field.
In the optical parity-time-symmetry systems, at certain values of their parameters, a phase transition from real eigenvalues of the Hamiltonian to the complex ones is observed. This phase transition, which can be directly or indirectly caused by a change in the measured physical quantity, leads to a sharp change in the optical properties of the system. This can be used to improve the accuracy of various optical sensors, in particular, angular rate sensors. Present communication is devoted to the analysis of previously announced and newly developed by the authors methods for measuring angular rates based on the use of the optical parity-time-symmetry systems. In particular, various variations of laser gyroscopes based on the systems of two identical coupled ring resonators that differ from each other only in the level of losses and gain are considered. We propose a new method for measuring the angular rate, based on the use of a parity-time-symmetry system of two straight coupled waveguides with a passive ring resonator connected to it.
The article presents a study of the dependence of the change in the shape of the resonance transmission line for optical thin dielectric gratings. The result of changing the duty cycle for high and low medium contrast while maintaining the amount of substance has been demonstrated. The results of the effect of the filling factor on the resonance transmission width and the frequency position in the normal TE wave drop are numerically investigated. Results for various options of a angles of the falling bunch at various coefficients of filling are presented. The effect of refractive index contrast of this structure on the width and shape of resonance lines was analyzed. In the first approximation, effective refractive indices and effective thicknesses for such structures were calculated. Conclusions are drawn about the conditions under which the structure can be considered optically thin.
To date, many works devoted to the influence of grazing angle on the spectral properties of nanostructured metasurfaces have been published. In this case, the dependence of the spectrum on grazing angle was previously considered within the framework of solving filtering problems, for example: constructing tunable optical filters based on metasurfaces; development of a bandpass filter with characteristics that are minimally dependent on the angle of incidence of light (angular tolerant color filter), etc. We propose to use the described property of nanostructured metasurfaces for solution of an inverse problem – determination of light incidence angle from the change in the metasurface spectral response. It will provide no-contact determination of an inclination angle of an object, on which the metasurface is installed; it is a step towards creating a miniature and accurate angle sensor. We consider the idea of using metasurfaces to measure inclination angles of objects on the basis of dielectric subwavelength gratings using computer simulation. We also analyze the possibility of simultaneous measurement of rotations (inclination angles) along two orthogonal axes using the same nanostructured metasurface.
The principle of operation of all resonator micro-optical gyroscope prototypes developed to date involves frequency scanning of the ring resonator. In previous works on this topic, we proposed and considered an optical resonator gyroscope scheme that does not require frequency scanning of the ring resonator. There two counterpropagating waves pass along the same optical path. It reduces the parasitic nonreciprocity, which leads to additional errors in measuring the angular velocity in most of the known schemes. In addition, this scheme allows further reduction of gyro prototypes dimensions. In this work, we simulate a resonator gyroscope made according to the described scheme. In this case, we simulate both the optical path of the proposed resonator gyroscope and the system for generating the output signal. Using the model, we evaluate its characteristics, including limiting sensitivity, operating range, etc.
The most promising type of micro-optical gyro is a resonator gyroscope. At the same time, the principle of operation of all prototypes of resonator micro-optical gyroscopes developed to date involves scanning a passive ring resonator in frequency. We devoted this work to a new approach to the construction and operation principle of a resonator micro-optical gyroscope. This approach does not require scanning a passive ring resonator in frequency and is realized through the use of a Mach–Zehnder modulator with a passive ring resonator connected to one of its arms. It was shown that, with this approach, the angular velocity can be determined, first, by the difference between the maxima and minima of the radiation power at the output of the Mach–Zehnder modulator when the optical length of one of its arms is modulated and, second, by the displacement of these maxima and minima. A common drawback of all considered angular velocity measurement methods utilizing the Mach–Zehnder modulator is the limited measurement range. For the resonator considered in this paper, the measurement range is of the order of ±1500 rad / s.
In recent decades a noticeable surge in research on nanostructured materials and their interactions with light has been observed. This is explained not only by basic interest, but also by the potential of miniaturization of devices and the expansion of their functional capabilities through the use of metasurfaces. On the other hand, in the last decade a pronounced tendency towards miniaturization of position control and navigation systems can be observed either. A need of positioning and navigation of small-sized mobile objects arises frequently. At the same time, the size of controlled objects is constantly decreasing, and the development of sensors for micro- and nanoscale objects is already required nowadays. Therefore, the use of nanostructured metasurfaces in position control and navigation systems seems to be extremely promising. We focus on the use of nanostructured metasurfaces for rotation angle determination. We discuss a new rotation angle measurement method where metasurface amplitude response is used, its main advantages and disadvantages are demonstrated, a variant of its improvement is proposed.
The present paper considers a ring confocal resonator in which the fulfillment of the confocal condition and the spectrum degeneracy are achieved through the use of a concave toroidal reflective surface with specified values of curvature radii in two main meridional sections. Such resonators can be used, in particular, as sensors in resonator micro-optic gyroscopes resonant optical gyroscope. This work is devoted to a review of technologies suitable for manufacturing of ring confocal resonators, and to an estimation of the deviations of the geometric parameters of confocal resonators acceptable during this manufacturing. To achieve this, the Fox and Li method is used, which was earlier modernized to calculate ring resonators with astigmatic reflecting elements.
Holographic wavefront sensors are the convenient tool for the fast, cheap and computation lacking wavefront analysis. The use of holographic filters-correlators makes it possible to decompose the wavefront along the basis of Zernike polynomials or to represent it as a set of piston segments. The paper considers possible application of such a technique for beam decomposition along other basis like Hermite-Gauss, Laguerre-Gauss and so on sets.
In the modern world there is a pronounced tendency for miniaturization. It applies to navigation systems and sensors used in them. Due to this, micromechanical gyroscopes in particular, became widespread, which made it possible to measure the angular velocity of miniature objects. But their sensitivity to accelerations and vibrations limits the range of their application. Currently, research in the direction of minimizing the size of general and precise optical gyroscopes is relevant, i.e. the development of micro-optical gyros. The most promising type of micro-optical gyro is a resonator one. Wherein the principle of operation of all prototype resonator micro-optical gyroscopes developed to date involves the scanning of a passive ring resonator in frequency. This work is devoted to a new approach to the construction and principle of operation of a resonator micro-optical gyroscope. This approach does not require scanning the passive ring resonator in frequency and is achieved through the use of a Mach-Zehnder modulator, one of whose arms is connected to a passive ring resonator. This allows to simplify the design of a micro-optical gyroscope, to obtain a mutual configuration, and to drop the tunable laser (required in most schemes) in favor of a laser with a constant generation frequency. The paper also discusses the limitations of the new approach and ways to overcome them.
In this paper, the determination of the topological charge of the vortex beams by means of shearing interferometry was achieved, for both common and non-common path shearing interferometers, using simple yet effective optical elements. The recording and analysis of interference patterns from different setups was accomplished using: cyclic, rotational and reversal shearing interferometers. The use of cyclic and rotational shearing interferometers resulted in interference patterns with two oppositely oriented forks for both setups. However, with the reversal shearing interferometer, a single forked pattern was obtained and a mathematical approximation was deduced.
Resonators with an equidistant spectrum are often required in optics. One of the ways to obtain it is the frequency degeneracy of the resonator mode, which is observed, for example, in the well-known classical (linear) confocal resonator. At the same time, there exist configurations of ring resonators similar to it in terms of their properties—ring confocal resonators. In the first approximation, they can be obtained using several reflecting surfaces in the cavity, at least one of which is concave toroid with radii of curvature in the two main meridional sections ensuring the confocal condition and the degeneracy of the spectrum. Such resonators can be used, in particular, as sensitive elements of miniature optical gyroscopes. We consider the specifics and properties of ring confocal resonators and the conditions necessary to obtain them. Using the modified Fox and Li method to calculate open-ring resonators with astigmatic reflective surfaces, the field of the ring confocal resonator is simulated.
We report the results of analysis of ways of application of nanostructured metasurfaces in rotation angle sensor (angle encoders). The dependence of optical properties of nanostructured metasurfaces upon their orientation relative to the incident optical radiation service as the basis of the study. The metasurfaces’ response to the incident radiation allows to judged on the mutual orientation of the radiation source and the metasurface. This allows to use metasurfaces as angle encoder scales. We discuss the possibility of using of amplitude and phase response of different types of metasurfaces. The main attention is paid to metasurfaces in the form of plasmonic nanorods, Pancharatnam–Berry elements and Cshaped antennas. The overall dimensions of the scales of angular encoders based on metasurfaces (width and length or diameter) can be tens of microns or less. Thus, the use of metasurfaces in angular encoders allows to reduce their size by orders of magnitude. Alongside, the use of metasurfaces should allow to realize non-contact measurements of the rotation angle (when only the scale based on the metasurface is placed on the controlled object or a part of an object itself acts as a scale) and to implement an absolute rotation angle sensor without significant increase of its size and manufacture complexity.
Often, optical devices require resonators with a limited set of natural frequencies and an equidistant spectrum. These requirements are satisfied by ring confocal resonators. Such resonators can be manufactured as a single monolithic element (prism) and used, in particular, as sensitive elements of miniature optical gyroscopes. As a result of external mechanical and thermal effects and imperfection of manufacturing technology, the reflecting surfaces of ring confocal resonators can be misaligned. This paper is devoted to the analysis of the effect of these misalignments on the optical properties of resonators. OOFELIEMultiphysics software is used to calculate the deformations arising in the resonator as a result of external effects. The influence of the deformation of the resonator on its optical properties is estimated using the modified method of Fox and Lee.
In recent years, the optical resonators of whispering gallery modes (WGMs) have attracted increasing interest in the scientific community. These are the axially symmetric dielectric resonators (spherical, disk, torus, bottle-shaped, etc.) with smooth edges that support the existence of WGMs due to the total internal reflection from the surface of the resonator. The rotation of the WGM resonators with respect to the inertial space causes changes in their radii. This, in turn, leads to the reciprocal (the same for light beams travelling in opposite directions) spectral shift of the WGMs. Thus, the rotation of such resonators causes a spectral shift, by which it is possible to calculate the motion parameters. Earlier the prospects of creation of the angular velocity sensor on the basis of this effect were discussed. Spherical, torus, and disk-shaped resonators were considered as possible sensitive elements. This work is devoted to the analysis of the influence of rotation on the mutual shift of the WGM of bottle-shaped resonators. An important part of the work is the study of cross-sensitivity of bottle resonators to rotation.
In most experimental installations and prototypes of miniature (the largest size of the sensing element from hundreds of μm to 2 cm) optical gyros, the waveguide passive ring resonators are used as sensing elements. In this case, only singlemode waveguides are used, since the use of multimode waveguides is impossible due to the dispersion of modes. For the same reason, most nonplanar ring resonators cannot be used. Nevertheless, there are confocal configurations of the ring resonators with strongly degenerate and equidistant spectrum. The application of such configurations as sensing elements allows to avoid the negative effect of the mode dispersion. Replacing the waveguide ring resonator on the confocal one can give some advantages for some types of miniature optical gyros (for example, those using the phase characteristic of a passive ring resonator). This work is devoted to the analysis of these optical gyros types and the advantages that the use of ring confocal resonator can give.
Resonators with an equidistant spectrum are required in optics quite often. One of ways to obtain them is to use degeneracy of the frequencies of the resonator modes, which is observed, for example, in well-known confocal resonators. At the same time it is possible to find configuration of the ring resonator with a similar properties – confocal ring resonator. In the first approximation, the ring confocal resonator can be obtained using several (at least three) reflecting surfaces: flat and concave toroidal with the radii of curvature in the two main meridional sections ensuring the fulfillment of the confocality condition and the degeneration of the spectrum. Such resonators can be manufactured as a single monolithic element (prism) and used, in particular, as sensing elements of miniature optical gyroscopes. This work is devoted to the study of the properties of ring confocal resonator with the use of multiphysical modeling.
Optical resonators of whispering gallery modes are dielectric axially symmetric resonators with smooth edges that support the existence of whispering gallery modes due to full internal reflection from the resonator surface. Centrifugal forces caused by the rotation of material objects can lead to their mechanical deformation. This is true for resonators of the whispering gallery modes, and when this occurs, the variation of the radius of the working section of the cavity takes place. As is known, the frequencies of whispering gallery modes are inversely proportional to the radius of the working section. Thus, under the influence of centrifugal forces, a reciprocal (the same for opposite directions of the cavity circuit bypass by light) shift of the whispering gallery modes frequencies occurs. Optical methods allow to determine this shift with high accuracy. This can be used in practice for measuring angular velocity and create a miniature angular rate sensor. However, the reciprocal nature of the shift does not allow to judge about the sign of the angular rate (clockwise or counterclockwise rotates the object). In this paper, we propose to solve this problem by applying the initial displacement of the output characteristic point (bias). The perspectives of applying both constant and alternating sign initial displacements are considered. Also, this approach should allow to increase sensitivity to low angular velocities and reduce the nonlinearity of the output characteristic.
In recent years, whispering gallery mode optical resonators are attracting ever-growing interest of the scientific community. They are axially symmetric dielectric resonators (spherical, disk-like, toroidal, bottlelike etc) with smooth edges that support the existence of whispering gallery modes by total internal reflection on the surface of the resonator. The rotation of the whispering gallery modes resonators with respect to the inertial space causes changes of their radiuses. This, in turn, leads to mutual (same for the opposite directions of the resonator bypass) spectral shift of whispering gallery modes. Thus, the rotation of such resonators causes a spectral shift, registering which one can calculate the motion parameters. Earlier, the prospects of creating an angular velocity sensor based on this effect were considered. Аt the same time the spherical, disk-like and toroidal resonators were considered as sensitive elements of this sensor. This paper is devoted to the analysis of the effect of rotation on the mutual frequency shift of the whispering gallery modes of bottle-shaped resonators. An important aspect of this work is the investigation of the cross-sensitivity to rotation of bottle resonators. The study is based on the results of the simulation in OOFELIEMultiphysics software.
The optical whispering-gallery mode (WGM) resonators are axially symmetrical resonators with smooth edges, supporting the existence of the WGMs by the total internal reflection on the surface of the resonator. As of today, various types of such resonators have been developed, namely the ball shaped, tor shaped, bottle shaped, disk shaped, etc. The movement of WGM resonators in inertial space causes the changes in their shape. The result is a spectral shift of the WGMs. Optical methods allow to register this shift with high precision. It can be used in particular for the measurement of angular velocities in inertial orientation and navigation systems. However, different types of resonators react to the movement in different manners. In addition, their sensitivity to movement can be changed when changing the geometric parameters of these resonators. The work is devoted to investigation of these aspects.
The influence of centrifugal forces on angular velocity sensors that measure a spectral shift of whispering-gallery modes (WGMs) is investigated. Spherical WGM resonators of different materials are considered the sensing elements. The study is based on the results of the simulation in OOFELIE::Multiphysics software.
Often resonators with an equidistant spectrum are required in optics. One of ways of their receiving is the degeneracy of the frequencies of the resonator modes. For example, it is observed in the well-known classical confocal (linear) resonator. At the same time exist similar to him on properties of the configuration of the ring resonators – the confocal ring resonators. In the first approximation they can be received using in the resonator at least one concave toroidal reflective surface with the values of the radiuses of curvature in the two main meridional sections providing performance of the confocal condition and degeneration of the spectrum. For example, such resonators can be used as sensitive elements of miniature optical gyroscopes. For today properties of the confocal ring resonators have not been practically studied. This work is devoted to investigation of the confocal ring resonators with the use of computer modeling.
The optical whispering gallery modes resonators are axially symmetrical resonators with smooth edges, supporting the existence of the whispering gallery modes by the total internal reflection on the surface of the resonator. For today various types of such resonators were developed, namely the ball-shaped, tor-shaped, bottle-shaped, disk-shaped etc. The movement of whispering gallery modes resonators in inertial space causes the changes of their shape. The result is a spectral shift of the whispering gallery modes. Optical methods allow to register this shift with high precision. It can be used in particular for the measurement of angular velocities in inertial orientation and navigation systems. However, different types of resonators react to the movement on a miscellaneous. In addition, their sensitivity to movement can be changed when changing the geometric parameters of these resonators. This work is devoted to a research of these aspects.
Optical whispering gallery modes resonators are characterized by unique properties: ultrahigh quality factor, small amount of the modes and small size. It allows to use them in compact high-precision measuring devices. In particular these resonators can be used in the composition of gyros. For today all researches, devoted to the application of the whispering gallery modes resonators in gyros, deals only with one of induced by the rotation effects (Sagnac effect or the influence of centrifugal forces on the resonator size). In this work we study the interrelation of the effects caused by the rotation of the whispering gallery modes resonator. Also in work we consider the possibility of joint application of both effects (the influence of centrifugal forces and Sagnac effect) for measuring angular velocity.
Influence of the centrifugal forces on angular velocity sensors that measure a spectral shift of whispering gallery modes is investigated. Spherical whispering gallery mode resonators of different materials are considered as sensing elements. The study is based on the results of the simulation in OOFELIE::Multiphysics software.
Influence of the centrifugal forces on angular velocity sensors that measure a spectral shift of whispering gallery modes is investigated. Spherical whispering gallery mode resonators of different materials are considered as sensing elements. The study is based on the results of the simulation in OOFELIEMultiphysics software.
The parameters of whispering gallery modes resonators can be significantly modified under the action of external factors, for instance, in the case of resonator movement. The effects, which take place in the moving resonators of whispering gallery modes, can be employed for measuring of the angular velocity. In this work we was compared the influence of centrifugal forces and the Sagnac effect on the eigenfrequencies (wavelengths) of whispering gallery modes resonators. Also work is devoted mutual relationships of the effects.
The article is devoted to assessing the impact of various external factors on the characteristics of microoptical gyroscope sensing elements. The rating is based on the results of a m ultiphysical modeling using software OOFELIE: Multiphysics.
The review paper considers the state-of-the-art in the technique of the small-size optical gyros, based on the use of
passive ring-shaped optical cavities (resonators).
We present the results of experimental investigation of measuring the wavefront distortions, accumulated during propagation of the bi-chromatic (0.53 and 1.06 μm) radiation propagation along the in-door atmospheric path by the pair of Shack-Hartmann wavefront sensors. The wavefront distortions for two wavelengths are compared, and the correlation between these distortions is revealed.
The article is devoted a ring multibeam interferometer. The last few decades such an interferometer is considered as the most promising sensitive element of inertial microoptical angular velocity sensors. All approaches to microoptical angular velocity sensors design are using only amplitude characteristics of interferometer for determining the angular velocity. Our results indicate that one can use the phase characteristics for the same goal. The method measurement of angular velocity with use of the phase and amplitude characteristics of ring interferometer was developed. The paper considers the advantages of using phase characteristic of ring multibeam interferometer.
Passive ring cavities are now treated as the most promising sensitive elements for cheap and technologically simple micro-optical gyros for mass production. Usually the single-mode planar waveguides are considered to be the only possible technology for such devices’ implementation. However, our analysis shows that in some cases the confocal ring cavity, characterized by the degeneration of transverse modes, can be the better alternative for such a device technology. We consider possible advantages and disadvantages of such an approach, its limitations, and technology prospects.
Passive ring cavities are now treated as the most promising sensitive elements for cheap and technologically simple microoptical gyro for mass production. Usually the single-mode planar waveguides are considered to be the only possible technology for such devices implementation. However, our analysis shows that in some cases the confocal ring cavity, characterized by degeneration of transverse modes, can be the better alternative for such a device technology. The paper considers possible advantages and disadvantages of such an approach, its limitations and technology prospects.
The paper considers the possibility to organize the phase measurements of the rotation speed in the ring-shaped single mode passive cavity, supplied by lone power divider (directed coupler).
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