Optical path device based on metasurface structure

Abstract

The utility model discloses an optical path device based on a metasurface structure, which relates to the technical field of quantum precision measurement and comprises an optical path acting part and an optical path channel, the surface of the optical path acting part is provided with the metasurface structure, and the optical path acting part is connected with the optical path channel. The metasurface structure comprises a substrate layer, a modulation layer and a top layer. In the aspect of precision adjustment, a metasurface structure is arranged on the surface of a light path action part, and the angle of a light beam in a given incident polarization direction is changed through the structure, so that the polarization state of light emitted into the atomic gas chamber is kept consistent, and the measurement precision is improved; in the aspect of simplifying the structure of the device, a metasurface polarization-maintaining reflector is arranged in a light path acting part, discontinuous phase change of an anisotropic material is realized only through the metasurface polarization-maintaining reflector, and the structure of the whole light path device is simplified; in the aspect of reducing the light path volume, a nanoscale metasurface structure is arranged on the surface of the light path acting part, and the light path volume of the atom magnetometer is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of quantum precision measurement, in particular to an optical path device based on a super surface structure. Background Art

[0002] Gyroscopes are used to measure the rotation and direction of objects and are one of the most important sensors in inertial navigation and positioning systems. Magnetometers have similar structures to gyroscopes and are widely used in military, medical, aerospace and other fields. The miniaturization of magnetometers and gyroscopes has good prospects and is gaining more and more attention. The principles of atomic gyroscopes and magnetometers are basically similar. However, existing atomic gyroscopes and magnetometers are large in size, which is not convenient for large-scale applications and cannot be adapted to a variety of physical usage environments.

[0003] Chinese patent document CN114061558A discloses a "nuclear magnetic resonance gyroscope". It uses a pump light transmitter, an acousto-optic modulator, an atomic gas chamber, a three-dimensional compensation coil and a signal generator. The pump light transmitter is used to transmit pump light. The acousto-optic modulator is arranged on the optical path of the pump light. The atomic gas chamber is arranged on the optical path of the pump light after passing through the acousto-optic modulator. The pump light is incident on the atomic gas chamber along the Z-axis direction. The atomic gas chamber is arranged in the space surrounded by the three-dimensional compensation coil. The signal generator is respectively connected to the control end of the acousto-optic modulator and the three-dimensional compensation coil. Although this patent has modified the coil, it cannot more effectively reduce the size of the gyroscope itself. Summary of the invention

[0004] The utility model mainly solves the technical problem that the volume of the original gyroscope optical path cannot be reduced, and provides an optical path device based on a metasurface structure. In the optical path device, a metasurface structure is provided on the surface of the optical path action part. The volume of the optical path action part is reduced by the metasurface structure, thereby optimizing the performance of the atomic gyroscope and breaking through the limitation of the volume of the traditional optical element on the optical path volume of the atomic gyroscope.

[0005] The above technical problems of the utility model are mainly solved by the following technical solutions: the utility model comprises an optical path action part and an optical path channel, the surface of the optical path action part is provided with a super surface structure, and the optical path action part is connected to the optical path channel.

[0006] Preferably, the optical path channel includes a longitudinal optical path channel and a transverse optical path channel, the longitudinal optical path channel includes a left longitudinal optical path channel and a right longitudinal optical path channel, a middle longitudinal optical path channel is provided between the left longitudinal optical path channel and the right longitudinal optical path channel, and the transverse optical path channel is connected to the top of the longitudinal optical path channel.

[0007] Preferably, the optical path action part includes a metasurface half-wave plate and a photodetector, the photodetector is arranged at the bottom end of the left longitudinal optical path channel, the metasurface half-wave plate is arranged on the left longitudinal optical path channel and the middle optical path channel, the polarization-maintaining reflector is arranged at the top of the left longitudinal optical path channel and the right longitudinal optical path channel, an atomic gas chamber is arranged between the polarization-maintaining reflectors on both sides, the atomic gas chamber is arranged at the top of the middle longitudinal optical path channel, a metasurface adjustable light intensity circular polarization polarizer is also arranged on the middle longitudinal optical path channel, a laser generator is also arranged in the middle longitudinal optical path channel and the right longitudinal optical path channel, and a metasurface transmission polarization beam splitter is arranged above the photodetector.

[0008] Preferably, the surface of the metasurface half-wave plate is provided with a base layer and a modulation layer, the base layer is provided with a silicon dioxide layer, the modulation layer is provided with a nanocolumn layer and a photoresist material layer, and the base layer is arranged below the modulation layer.

[0009] Preferably, the metasurface adjustable light intensity circular polarization polarizer comprises a base layer, a modulation layer and a top layer.

[0010] Preferably, the metasurface polarizer comprises a substrate layer and a modulation layer.

[0011] Preferably, the metasurface polarization-maintaining reflector comprises a silver column layer and a silver layer, a magnesium difluoride layer is provided between the silver column layer and the silver layer, the metasurface transmission polarization beam splitter comprises a nanocolumn layer and a photoresist material layer, and a silicon dioxide layer is provided under the photoresist material layer.

[0012] The beneficial effects of the utility model are as follows: in terms of precision adjustment, compared with traditional optical elements, this patent sets a metasurface structure on the surface of the optical path action part, and changes the angle of the light beam of a given incident polarization direction through the structure, so that the light beam can be uniformly adjusted as expected after passing through the optical path action part, and finally significantly improves the atomic polarization efficiency. And because both the pump light and the detection light are purified, the polarization state of the light injected into the atomic gas chamber is almost consistent, which improves the measurement accuracy; in terms of simplifying the device structure, a metasurface polarization-preserving reflector is set in the optical path action part, and the discontinuous phase change of the anisotropic material can be achieved only through this component, so that the incident light does not change the polarization state of the light after being reflected by the reflector, simplifying the structure of the entire optical path device; in terms of reducing the volume of the optical path, since the metasurface structures set on the surface of the optical path action part are all nanometer-level, they can be directly attached to the surrounding of the atomic gas chamber, and thus the optical path volume of the atomic magnetometer can be greatly reduced, and finally the volume of the entire optical path device can be simplified and reduced without affecting the normal operation of the optical path device, and the adaptation range of the optical path device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1It is a structural diagram of an optical path device based on a super surface structure of the utility model.

[0014] Figure 2 It is a distribution diagram of a super surface structure of the utility model.

[0015] Figure 3 It is a structural diagram of a substrate layer of a super-surface adjustable light intensity circular polarization polarizer of the utility model.

[0016] Figure 4 It is a structural diagram of a modulation layer of a super-surface adjustable light intensity circular polarization polarizer of the utility model.

[0017] Figure 5 It is a structural diagram of the top layer of a super-surface adjustable light intensity circular polarization polarizer of the utility model.

[0018] Figure 6 This is a simulation result diagram of the light of a super-surface adjustable light intensity circular polarizer of the utility model.

[0019] Figure 7 It is a structural diagram of a supersurface half-wave plate of the utility model.

[0020] Figure 8 This is a simulation result diagram of a supersurface half-wave plate light of the utility model.

[0021] Fig. 9 This is a simulation result diagram of light from a super-surface polarizer of the utility model.

[0022] Fig.10 It is a structural diagram of a super-surface polarization reflector of the utility model.

[0023] Fig.11 This is a simulation result diagram of light of a super surface polarized reflector of the utility model.

[0024] Fig.12 It is a structural diagram of a super-surface transmission polarization beam splitter of the utility model.

[0025] Fig.13 It is an adjustment diagram of a super surface structure of the utility model.

[0026] In the figure, 1. metasurface half-wave plate, 2. metasurface adjustable light intensity circular polarization polarizer, 3. polarization-maintaining reflector, 4. metasurface polarizer, 5. metasurface transmission polarization beam splitter, 6. atomic gas chamber, 7. photodetector, 8. laser generator, 9. nanocolumn layer, 10. photoresist material layer, 11. silicon dioxide layer, 12. aluminum column layer, 13. left longitudinal optical path channel, 14. middle longitudinal optical path channel, 15. right longitudinal optical path channel, 16. lateral optical path channel, 17. top layer, 18. modulation layer, 19. modulation layer, 20. silver column layer, 21. magnesium difluoride layer, 22. silver layer. DETAILED DESCRIPTION

[0027] The technical solution of the utility model is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0028] Embodiment: In this embodiment, an optical path device based on a metasurface structure is used. The gyroscope is used to measure the rotation and direction of an object. It is one of the most important sensors in an inertial navigation and positioning system. It has a wide range of application requirements in various fields, and the principles of atomic gyroscopes and magnetometers are similar. Due to the gradual expansion of the demand, it is necessary to reduce the volume of the entire gyroscope in order to maximize its adaptability range. Therefore, the miniaturization of the overall volume of the gyroscope can meet the demand. The prior art reduces the volume of the optical path by adding an etched silicon wafer to the side of the atomic vapor chamber instead of a reflector. However, the inherent volume of a quarter glass sheet and a polarization beam splitter makes the entire optical path still limited by the volume of traditional optical components, making it difficult to further reduce it. In order to pursue a small volume, the prior art uses a laser beam as both a pump light and a detection light. The pump light and the detection light have the same frequency, which is not conducive to the extraction of the resonant frequency ω1 after being received by the photodetector. In order to solve the problem that the prior art cannot further reduce the size of the optical path device.

[0029] like Figure 1As shown, in this embodiment, an optical path device based on a metasurface structure is designed, and an atomic gyroscope optical path is formed by the interaction of an optical path channel and an optical path action part. A laser generator 8 is provided at the bottom of the right longitudinal optical path channel and the middle longitudinal optical path channel. The laser generator 8 arranged at the bottom of the right longitudinal optical path channel emits a wavelength of 780nm, which is purified by the upper metasurface polarizer 4 and then injected into the atomic gas chamber 6. The atomic gas chamber 6 is arranged at the top of the middle longitudinal optical path channel. At the same time, a laser generator 8 is also provided at the bottom of the middle longitudinal optical path channel to emit light with a wavelength of 795nm. The light passes through the metasurface half-wave plate 1 and the metasurface adjustable light intensity circular polarization polarizer 2 arranged on the middle longitudinal optical path and becomes left-handed light to enter the atomic gas chamber 6 to generate pump light. The light generated by the two parts of the laser generator 8 is divided into two beams by the metasurface transmission polarization beam splitter 5 after being acted on by the optical path action part on the middle longitudinal optical path and the right longitudinal optical path channel through the metasurface half-wave plate 1 on the left longitudinal optical path. The two beams of light are received by the photodetector 7. The entire optical path structure is mainly composed of the remaining optical path function parts arranged around the atomic gas chamber 6. In this embodiment, the light is divided into two beams of light in the optical path function part, and received by two photodetectors 7 arranged at the bottom end of the left longitudinal optical path to realize the circulation of light in the entire optical path device. By gathering all the optical path function parts around the atomic gas chamber 6, the surrounding layout structure can minimize the overall volume of the entire optical path device.

[0030] In addition to reducing the volume of the entire optical path device by means of the layout structure, in this embodiment, a super surface structure is simultaneously set on the surface of the optical path function part device, so that the size of each component of the optical path function part is further reduced, thereby promoting the simplification and reduction of the volume of the entire optical path device. Figure 2 As shown, in this embodiment, a metasurface structure provided at the optical path function part includes a base layer, a modulation layer, and several layers in the top layer. The three layers are arranged in the order of the modulation layer being provided at the bottom and the top layer being provided at the top. A metasurface structure is formed on the optical path function surface, and the volume of each optical path function part is reduced while ensuring the refraction of light. Fig.13 As shown, due to the application of the metasurface structure, the metasurface adjustable light intensity circular polarizer 2 can be combined with the metasurface half-wave plate 1 as shown in FIG. Figure 2 Placed close to the middle longitudinal optical path. Figure 3 , 4As shown in Figure 5, the metasurface structure of the metasurface adjustable light intensity circular polarizer 2 includes a base layer, a modulation layer and a top layer. The base layer material includes silicon dioxide, aluminum hexagonal and distributed elliptical nanocolumns; the modulation layer includes aluminum hexagonal and distributed elliptical nanocolumns with different parameters from the base; and the top layer includes periodically distributed silicon rectangular nanocolumns. The three layers of the metasurface structure are all wrapped with SU-8 photoresist materials of different specifications. In the base layer, an aluminum column layer is provided at the top, a silicon dioxide layer is provided at the bottom, and a photoresist material layer is provided between the aluminum column layer and the silicon dioxide layer. Elliptical nanocolumns are arranged in the base layer, and the parameters of the nanocolumns are that the major axis is 250nm, the minor axis is 90nm, and the height is 57nm. The distance between the centers of each elliptical nanocolumn is 278nm, and they are arranged in a hexagonal shape. When the light beam passes through the metasurface adjustable light intensity circular polarization polarizer 2, the above-mentioned nanocolumn structure receives the incident light with wavelengths of 780nm and 795nm and wraps it in a SU-8 photoresist material with a height of 144nm. The top of the modulation layer of the metasurface adjustable light intensity circular polarization polarizer 2 is set as an aluminum column layer, and a photoresist material layer is arranged below the aluminum column layer. The parameters of the elliptical nanocolumns in the modulation layer are as follows: the major axis is 250nm, the minor axis is 90nm, and the height is 57nm. The distance between the centers of each elliptical nanocolumn is 278nm, and they are arranged in a hexagonal shape. When the light beam passes through the metasurface adjustable light intensity circular polarization polarizer 2, the above-mentioned nanocolumn structure receives the incident light of 780nm and 795nm and wraps it in a SU-8 photoresist material with a height of 57nm.

[0031] The top layer of the metasurface adjustable light intensity circular polarizer 2 is provided with a nanocolumn layer and a photoresist material layer, and the nanocolumn layer is arranged above the photoresist material layer. Corresponding to the incident light with a wavelength of 780nm, the top layer is provided with a silicon rectangular nanocolumn with parameters of 195nm in length, 30nm in width, and 900nm in height for receiving; and for the incident light with a wavelength of 795nm, the top layer is provided with a silicon rectangular nanocolumn with parameters of 196nm in length, 32nm in width, and 900nm in height for receiving. After receiving, the above two kinds of light are wrapped in SU-8 with a height of 395nm. The distance between two adjacent rectangular nanocolumns is set in the y direction, the distance between the centers of each rectangle is 724nm, and the distance in the x direction is 836nm. The structure is as follows Figure 6As shown in the figure, the dots in the figure are the simulation results of the total transmittance of the metasurface adjustable light intensity circular polarizer 2 changing with the polarization angle of the incident light. The curve is the curve fitting result of the total transmittance of the metasurface adjustable light intensity circular polarizer 2 changing with the polarization angle of the incident light. It can be seen from the figure that the fitting result is close to the theoretical value. Therefore, by setting the metasurface structure on the surface of the part of the optical path, it is possible to achieve the result of the theoretical value of the area after the light is incident, meeting the expected expectation. The small figure in the large figure is the simulation result of the left-handed light purity changing with the polarization angle of the incident light. When the incident angle polarization angle is greater than 60°, it can be seen that the purity of the emitted left-handed light is very high.

[0032] like Figure 7 As shown, the supersurface half-wave plate 1 arranged in the left longitudinal optical path channel and the middle longitudinal optical path channel has a nanocolumn layer on the top layer and a silicon dioxide layer on the bottom layer, and a photoresist material layer is arranged between the nanocolumn layer and the silicon dioxide layer. Similarly, there is a supersurface structure on the surface of the supersurface half-wave plate 1, and this part of the structure includes a base layer and a modulation layer. The main material of the base layer is silicon dioxide, and the modulation layer includes periodically distributed silicon rectangular nanocolumns and SU-8 photoresist material with a refractive index of 1.55 wrapped on the nanocolumns. For incident light with a wavelength of 780nm, the modulation layer is provided with a rectangular nanocolumn with parameters of 174nm in length, 78nm in width, and 860nm in height, and a SU-8 photoresist material with a height of 270nm for processing; for incident light of 795nm, the modulation layer is provided with a rectangular nanocolumn with parameters of 178nm in length, 84nm in width, and 860nm in height, and a SU-8 photoresist material with a height of 272nm. For the two incident lights mentioned above, the periodic distance between the rectangular nanocolumns in the modulation layer is 330nm in the x-direction, and the length in the y-direction is 340nm. Figure 8 As shown in the figure, the diagonal line is the simulation result of the polarization angle reading of the outgoing light changing with the polarization angle of the incident light, and the horizontal line is the conversion deviation CD, which is defined as θpi+θpo-90, that is, the polarization angle of the incident light plus the polarization angle of the outgoing light minus 90°. Therefore, the simulation result of the conversion deviation CD changing with the polarization angle of the outgoing light is shown as follows Figure 8 As shown in the figure, the small figure is a partial enlarged view of the conversion deviation CD. As can be seen from the above figure, the metasurface half-wave plate 1 can achieve that when the polarization angle θpi of the incident light changes continuously from 0° to 90°, the polarization angle θpo of the emitted light can be uniformly and continuously adjusted from 90° to 0°.

[0033] The metasurface polarizer 4 is the metasurface adjustable light intensity circular polarization polarizer 2 above without the top structure, and is composed of a base layer and a modulation layer. When light passes through the metasurface polarizer 4, an elliptical nanocolumn with parameters of a major axis of 250nm, a minor axis of 90nm, and a height of 57nm is provided in the base layer, and the distance between the centers of each elliptical nanocolumn is 278nm, which is distributed in a hexagonal shape, wherein the incident light with wavelengths of 780nm and 795nm is processed by the nanocolumn and wrapped in a SU-8 photoresist material with a height of 57nm. At the same time, an elliptical nanocolumn with parameters of a major axis of 250nm, a minor axis of 90nm, and a height of 57nm is provided in the modulation layer of the metasurface polarizer 4, and the distance between the centers of each elliptical nanocolumn is 278nm, which synchronously assists in processing the incident light with wavelengths of 780nm and 795nm and wraps it in a SU-8 photoresist material with a height of 144nm. According to the above processing results, it is obtained Fig. 9 The curve in the large figure shows the simulation result of the transmittance of the y component of the outgoing light with the polarization angle of the incident light, and the line coincident with the x-axis in the large figure shows the simulation result of the x component. The small figure is a partially enlarged x component transmittance diagram, which shows that the x component of the light passing through the metasurface polarizer 4 will be eliminated.

[0034] like Fig.10 As shown, the metasurface structure of the metasurface polarization-maintaining reflector surface includes a base layer, an isolation layer, and a modulation layer. The top is a silver column layer, the bottom is a silver layer, and a magnesium difluoride layer is provided between the two layers, wherein the silver column layer includes uniformly distributed silver square nanocolumns. The height of the magnesium difluoride in the magnesium difluoride layer is 45nm. The silver square nanocolumns in the modulation layer have a side length of 50nm and a height of 35nm. The interval between each nanocolumn is 300nm. The above physical structure is used to receive incident light with wavelengths of 780nm and 795nm. After receiving the incident light, it generates Fig.11 The star in the figure is the simulation result, and the solid line is the law of reflection, where the incident angle is equal to the exit angle. It can be seen from the figure that the simulation results and the theoretical values ​​tend to be consistent, so the use of a metasurface structure on the surface of a metasurface polarization-preserving reflector can achieve the expected light receiving and reflection effect.

[0035] like Fig.12As shown, the metasurface structure on the surface of the metasurface transmission polarization beam splitter 5 includes a base layer and a modulation layer. Therefore, a nanocolumn layer is provided on the top of the metasurface transmission polarization beam splitter 5, a photoresist material layer is provided below the nanocolumn layer, and a silicon dioxide layer is provided below the photoresist material layer. The main material of the base layer of the metasurface transmission polarization beam splitter 5 is silicon dioxide, and the modulation layer includes silicon rectangular nanocolumns divided into several periods, each period contains five pairs of rectangular nanocolumns with different widths, each pair contains two identical nanocolumns, and SU-8 photoresist material wrapped around the nanocolumns. For incident light of 780nm and 795nm, the silicon rectangular nanocolumns of the modulation layer are divided into a group of five pairs, all of which are 500nm high, with one side length of 90nm, and the other side lengths of 55nm, 125nm, 163nm, 207nm and 249nm, respectively, wrapped in SU-8 photoresist material with a height of 300nm. The distance between adjacent nanocolumns along the x direction is 270 nm, and the distance between adjacent nanocolumn groups along the y direction is 395 nm, and the following results are obtained.

[0036] Angle of incidence / ° Outgoing Angle 1 / ° Extinction ratio at exit angle 1 Outgoing Angle 2 / ° Extinction ratio at exit angle 2 Angle / ° -2 -2.709 0.0014675 13.545 0.057982 16.254 -1 -1.505 0.0019971 15.351 0.04778 16.856 0 0.301 0.002413 16.555 0.056858 16.254 1 1.505 0.0027649 18.361 0.051199 16.856 2 2.709 0.0039117 19.565 0.061422 16.856

[0037] As shown in the five different incident angles in the table above, in the atomic gyroscope optical path, the incident light can be incident perpendicular to the metasurface transmission polarization beam splitter 5, and the extinction ratio ER is defined as the normal emission direction is Ty / Tx, and the abnormal emission direction is Tx / Ty. Therefore, the ER of one of the outlets in the figure is 0.0024, and the ER of the other outlet is 0.057, which meets the requirements of the gyroscope optical path. Therefore, setting a metasurface structure in the metasurface transmission polarization beam splitter 5 can achieve the expected effect of this embodiment.

[0038] Therefore, as mentioned above, for the incident light of 780nm, the parameters of the modulation layer rectangular nanocolumns of the metasurface half-wave plate 1 in the optical path device based on the metasurface structure in this embodiment are 174nm long, 78nm wide, and 860nm high; the height of the modulation layer SU-8 photoresist material is 270nm. The parameters of the top silicon rectangular nanocolumns of the metasurface adjustable light intensity circular polarizer 2 are 195nm long, 30nm wide, and 900nm high, wrapped in SU-8 with a height of 395nm. For the incident light of 795nm, the parameters of the modulation layer rectangular nanocolumns of the metasurface half-wave plate 1 are 178nm long, 84nm wide, and 860nm high; the height of the modulation layer SU-8 photoresist material is 272nm. For incident light of 780nm and 795nm, the periodic distances between the rectangular nanocolumns in the modulation layer of the metasurface half-wave plate 1 are 330nm and 340nm, and the distance between the centers of two adjacent rectangular nanocolumns in the y direction is 724nm, and in the x direction it is 836nm. The parameters of the top silicon rectangular nanocolumns of the metasurface adjustable light intensity circular polarizer 2 are 196nm in length, 32nm in width, and 900nm in height, and are wrapped in SU-8 with a height of 395nm. The parameters of the elliptical nanocolumns in the modulation layer of the metasurface adjustable light intensity circular polarizer 2 are 250nm in major axis, 90nm in minor axis, and 57nm in height. The distance between the centers of each elliptical nanocolumn is 278nm, and it is wrapped in SU-8 with a height of 57nm. The parameters of the base layer elliptical nanocolumns of the metasurface polarizer 4 are a major axis of 250nm, a minor axis of 90nm, a height of 57nm, a distance between the centers of each elliptical nanocolumn of 278nm, and wrapped in SU-8 with a height of 144nm. The parameters of the first modulation layer elliptical nanocolumns are a major axis of 250nm, a minor axis of 90nm, a height of 57nm, a distance between the centers of each elliptical nanocolumn of 278nm, and wrapped in SU-8 with a height of 144nm. The parameters of the second modulation layer elliptical nanocolumns are a major axis of 250nm, a minor axis of 90nm, a height of 57nm, a distance between the centers of each elliptical nanocolumn of 278nm, and wrapped in SU-8 with a height of 57nm. The height of the isolation layer magnesium difluoride of the metasurface polarization-maintaining reflector is 45nm. The modulation layer silver square nanocolumns of the metasurface polarization-maintaining reflector have a side length of 50nm and a height of 35nm, and the spacing between each nanocolumn is 300nm. The silicon rectangular nanocolumns of the modulation layer of the metasurface transmission polarization beam splitter 5 are divided into five pairs, and the two nanocolumns in a pair are exactly the same, all of which are 500nm high, one has a side length of 90nm, and the other has side lengths of 55nm, 125nm, 163nm, 207nm and 249nm, respectively, wrapped in SU-8 with a height of 300nm. The intervals between two adjacent groups of nanocolumns in the modulation layer of the metasurface transmission polarization beam splitter 5 are 270nm along the x-direction and 395nm along the y-direction.The following technical effects can be achieved by using an optical path device based on a metasurface structure: In terms of high precision, the metasurface structure of this embodiment significantly improves the performance compared to traditional optical elements. For a light beam with a given incident polarization direction, the metasurface half-wave plate 1 can achieve uniform polarization adjustment from 0° to 90°. For the metasurface adjustable light intensity circular polarization polarizer 2, when the polarization angle of the incident light exceeds 66°, the purity of the emitted left-handed light can reach above 0.999, which significantly improves the atomic polarization efficiency. In addition, both the pump light and the probe light are purified, so that the polarization state of the light injected into the atomic gas chamber 6 is almost consistent, which improves the measurement accuracy; in terms of device simplification, the metasurface polarization-preserving reflector used in the utility model changes the phase of the anisotropic material discontinuously, so that the incident light does not change the polarization state of the light after being reflected by the reflector, which reduces the use of optical elements compared to the traditional optical path, making the device more streamlined; and in terms of reducing the volume, the thickness of each metasurface structure used in this embodiment is at the nanometer level and there is no limit on the length and width, which is convenient for free combination and use.

Claims

1. An optical path device based on a metasurface structure, characterized in that: It includes an optical path action part and an optical path channel, the surface of the optical path action part is provided with a super surface structure, and the optical path action part is connected to the optical path channel; the optical path channel includes a longitudinal optical path channel, and the longitudinal optical path channel includes a left longitudinal optical path channel and a right longitudinal optical path channel, and a middle longitudinal optical path channel is provided between the left longitudinal optical path channel and the right longitudinal optical path channel.

2. The optical path device based on the metasurface structure according to claim 1, characterized in that: The optical path channel includes a longitudinal optical path channel and a transverse optical path channel. The longitudinal optical path channel includes a left longitudinal optical path channel and a right longitudinal optical path channel. A middle longitudinal optical path channel is provided between the left longitudinal optical path channel and the right longitudinal optical path channel. The transverse optical path channel is connected to the top of the longitudinal optical path channel.

3. The optical path device based on the metasurface structure according to claim 2, characterized in that: The optical path action part includes a metasurface half-wave plate and a photodetector, wherein the photodetector is arranged at the bottom end of the left longitudinal optical path channel, the metasurface half-wave plate is arranged on the left longitudinal optical path channel and the middle optical path channel, the polarization-preserving reflector is arranged at the top of the left longitudinal optical path channel and the right longitudinal optical path channel, an atomic gas chamber is arranged between the polarization-preserving reflectors, the atomic gas chamber is arranged at the top of the middle longitudinal optical path channel, a metasurface adjustable light intensity circular polarization polarizer is also arranged on the middle longitudinal optical path channel, a laser generator is also arranged in the middle longitudinal optical path channel and the right longitudinal optical path channel, and a metasurface transmission polarization beam splitter is arranged above the photodetector.

4. The optical path device based on the metasurface structure according to claim 3, characterized in that: The surface of the metasurface half-wave plate is provided with a base layer and a modulation layer, the base layer is provided with a silicon dioxide layer, the modulation layer is provided with a nanocolumn layer and a photoresist material layer, and the base layer is arranged below the modulation layer.

5. The optical path device based on the metasurface structure according to claim 4, characterized in that: The metasurface adjustable light intensity circular polarization polarizer comprises a base layer, a modulation layer and a top layer.

6. The optical path device based on the metasurface structure according to claim 5, characterized in that: The metasurface adjustable light intensity circular polarization polarizer comprises a substrate layer and a modulation layer.

7. The optical path device based on a metasurface structure according to claim 3 or 6, characterized in that: The polarization-preserving reflector comprises a silver column layer and a silver layer, a magnesium difluoride layer is arranged between the silver column layer and the silver layer, the metasurface transmission polarization beam splitter comprises a nano column layer and a photoresist material layer, and a silicon dioxide layer is arranged under the photoresist material layer.

Images