A method for modulating photon spin using a spatial light modulator

Abstract

The present application relates to the technical field of spatial light modulator, disclose a kind of method for modulating photon spin using spatial light modulator, comprising the following steps: S1 light emitting step, light emission, S2 initial polarization modulation, the polarization state of light is modulated to along horizontal direction by the polarization beam splitter, S3 polarization angle adjustment, S4 spatial light modulation step, S5 detection analysis.In the present application, spatial light modulator is used to flexibly modulate phase to control the generation of different types of PHSE.We can modulate the polarized light beam passing through the spatial light modulator by designing different phases on the spatial light modulator, therefore, if circular polarization components need to be separated from each other and move along a predefined trajectory, we can achieve this by modulating the phase of the spatial light modulator. Therefore, the photon spin Hall effect and the devices relying on the photon spin Hall effect can be simply and flexibly regulated by spatial light modulator.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of home kitchen, in particular to a method for modulating photon spin by using a spatial light modulator. BACKGROUND

[0002] A spatial light modulator (SLM) is a device that modulates the spatial distribution of light waves. In principle, it can change the amplitude, phase, polarization and other characteristics of light. Its basic structure usually includes a control unit and a modulation unit. The control unit receives external signals to drive the modulation unit to work. In terms of application, spatial light modulators play a key role in the field of optical information processing. For example, it can encrypt images and hide image content by modulating light information. In holographic projection, the phase of light can be accurately controlled to generate three-dimensional holographic images. In adaptive optical systems, it can change the wavefront of light in real time according to the feedback information of the wavefront sensor, correct the aberration of the optical system, and improve the imaging quality.

[0003] The SOI of light can be greatly enhanced through the Pancharatnam-Berry (PB) phase related to polarization transformation. Due to the SOI caused by PB phase, people have proposed different ways of photon independent separation. These are considered to be different types of PHSE, mainly designed or discovered according to the propagation of spin states. For example, the linear phase gradient generated by the polarization grating causes two spin states to move in opposite directions, while the spherical phase causes spin-dependent focusing. Combined with the phase structure of spatial structured light beams, PB phase can generate spin-controlled flying vortex beams and self-focusing beams

[0004] The photon spin Hall effect has important application potential in nano-optics and quantum optics. It can be used to control and regulate the propagation direction of light, realize new optical devices and optical signal processing. In addition, the photon spin Hall effect is also in the field of topological Φ It should be noted that the photon spin Hall effect is a relatively new research field, and is still being intensively studied and explored. There are still many problems and challenges to be solved. The most urgent one is that although the photon spin Hall effect can be regulated, it often relies on the change of gradient refractive index or variable refractive index material. This determines that the PSHE cannot be simply and flexibly regulated. SUMMARY

[0005] In view of the defects of the prior art, the present application provides a method for modulating photon spin by using a spatial light modulator, which solves the problem that the PSHE cannot be simply and flexibly regulated in the prior art.

[0006] To achieve the above purpose, the present application is implemented by the following technical scheme: a method for modulating photon spin by using a spatial light modulator, comprising the following steps:

[0007] S1: light emitting step

[0008] starting the laser to emit light;

[0009] S2: initial polarization modulation

[0010] introducing the light emitted by the laser into a polarization beam splitter prism to modulate the polarization state of the light along the horizontal direction through the polarization beam splitter prism;

[0011] S3: polarization angle adjustment

[0012] passing the light modulated by the polarization beam splitter prism through a quarter-wave plate to adjust the polarization direction of the light to 45°;

[0013] S4: spatial light modulation step

[0014] introducing the light with a polarization direction of 45° into a spatial light modulator, and according to the model of the spatial light modulator, making the light perform reflection or transmission operation in the spatial light modulator and modulating the phase of the light;

[0015] S5: detection and analysis

[0016] acquiring the light reflected by the spatial light modulator and dividing it into two beams of P light and S light, introducing it into a charge-coupled device for reception and detection and analysis, and detecting and analyzing the related characteristics of the photon spin Hall effect.

[0017] Preferably, the laser emits a light spot with a diameter of 9mm, and if it is less than 9mm, a beam expander is used to enlarge the light spot, and the wavelength of the laser is 632.8nm.

[0018] Preferably, the polarization beam splitter prism has a size of 10mm*10mm*10mm, and is made of optical glass with a specific refractive index and extinction ratio, and the polarization state modulation is completed through the polarization beam splitter prism.

[0019] Preferably, the phase delay accuracy of the quarter-wave plate is within 1 / 300λ, and the polarization direction can be accurately adjusted to 45°.

[0020] Preferably, the spatial light modulator has a pixel size of 8um, a resolution of 1920*1200, a fill rate greater than or equal to 90.7%, and a refresh rate of 60Hz, and different phase patterns are displayed by loading a specific voltage distribution on the liquid crystal layer to modulate the photon spin.

[0021] The preferred charge-coupled device has a pixel size of 1.85um*1.85um, a resolution of 4032*3036, 1200 million pixels, an external size of 35mm*35mm*8.6mm, a working temperature of 0-50°C, and a storage temperature of -30-70°C. The P light and S light are detected and analyzed using an image acquisition algorithm, and the spin Hall effect related parameters of photons can be calculated based on the light intensity distribution and spot shape characteristics.

[0022] A device for modulating the spin of photons using a spatial light modulator, comprising the following devices:

[0023] Laser: for generating an initial light beam with a specific diameter of the exit spot;

[0024] Polarization beam splitter prism: with a size of 10mm*10mm*10mm, the main function is to modulate the polarization state of the input light beam;

[0025] Quarter-wave plate: capable of adjusting the polarization direction of the light after passing through the polarization beam splitter prism;

[0026] Spatial light modulator: which can adjust the liquid crystal molecules arranged horizontally inside according to different voltages loaded, and through flexible modulation of the phase of the light beam, reflection or transmission operation to modulate the spin of photons;

[0027] Charge-coupled device: for receiving the light reflected by the spatial light modulator and divided into P and S light, and detecting and analyzing it to obtain data information related to the spin Hall effect of photons, to assist in evaluating and studying the modulation of photon spin.

[0028] Preferably, the laser exit spot diameter is 9mm, and has a specific wavelength, such as 632.8nm. When the exit spot diameter is less than 9mm, a beam expander can be equipped to expand the spot size to the required size. The polarization beam splitter prism in this device is used to modulate the light polarization state to the horizontal direction.

[0029] Preferably, the quarter-wave plate in this device is used to adjust the light polarization direction to 45°, and make the light enter the subsequent components with appropriate polarization state. The spatial light modulator has a specific pixel size of 8um, a resolution of 1920*1200, a fill rate greater than or equal to 90.7%, and a refresh rate of 60Hz.

[0030] Preferably, the charge coupled device pixel size is 1.85um*1.85um, the resolution is 4032*3036, it has 12 million pixels, the size is 35mm*35mm*8.6mm, the working temperature range is 0-50 DEG C, and the storage temperature range is -30-70 DEG C.

[0031] The application provides a method for modulating photon spin by using a spatial light modulator.

[0032] 1. In the application, a spatial light modulator is used to flexibly modulate the phase to control the generation of different types of PHSE. We can modulate the polarized light beam passing through the spatial light modulator by designing different phases on the spatial light modulator, therefore, if circularly polarized components need to be separated from each other and move along a predefined trajectory, we can achieve this by modulating the phase of the spatial light modulator. Therefore, the photon spin Hall effect and the devices relying on the photon spin Hall effect can be simply and flexibly regulated by the spatial light modulator.

[0033] 2. The application can perform a series of modulation operations on the photon spin through the complete optical path system composed of related optical elements such as a polarization beam splitter (PBS), a quarter-wave plate (QWP), a spatial light modulator (SLM), and a charge coupled device (CCD), etc. After the photon spin is modulated, the P light and the S light reflected by the spatial light modulator and separated are received and detected by the CCD for analysis, so that the related data information of the photon spin modulation can be accurately obtained, which helps to deeply study the related characteristics of the photon spin Hall effect and to feedback and optimize the whole modulation process, and further improve the accuracy and effect of the regulation.

[0034] 3. The application can produce a variety of unique light manipulation effects by means of the design and loading of different phases such as vortex phase, spherical phase factor, etc. For example, the vortex phase can produce a specific spin offset, and the optical axis distribution pattern presents an oscillating spin-related offset; the spherical phase can cause a spin-related focusing effect. This provides more diversified means for the control of light propagation direction, the research and development of new optical devices, and the processing of optical signals in the field of optics. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is a flow chart of the method for modulating photon spin by using a spatial light modulator;

[0036] Figure 2 It is a schematic diagram of the photon spin of the application;

[0037] Figure 3 It is a light path design diagram of the application;

[0038] Figure 4This is a schematic diagram of the spiral phase of the present invention;

[0039] Figure 5 This is a schematic diagram of the spherical phase of the present invention;

[0040] Figure 6 This is a schematic diagram of the spin-related offset of the oscillation generated by the vortex phase of the present invention.

[0041] Figure 7 This is a schematic diagram of photon spin-correlated focusing generated by the spherical phase of the present invention. Detailed Implementation

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example:

[0044] Please see the appendix Figure 1 - Appendix Figure 7 This invention provides a method for modulating photon spin using a spatial light modulator, comprising the following steps:

[0045] S1: Light emission step

[0046] Turn on the laser to emit light;

[0047] S2: Initial polarization modulation

[0048] The light emitted from the laser is guided into a polarizing beam splitter, and the polarization state of the light is modulated to be horizontal through the polarizing beam splitter.

[0049] S3: Polarization angle adjustment

[0050] The light modulated by the polarizing beam splitter is passed through a quarter-wave plate, and the polarization direction of the light is adjusted to 45°.

[0051] S4: Spatial light modulation steps

[0052] Light with a polarization direction of 45° is introduced into a spatial light modulator. Depending on the model of the spatial light modulator, the light is reflected or transmitted within the spatial light modulator, and the phase of the light is modulated.

[0053] The process requires designing a phase diagram, for example... Figure 4 Mid-vortex phase and Figure 5The PSHE generated by the oscillating spherical phase factor can be represented in more different forms by the spin-dependent splitting of Lcos;

[0054] The linear phase gradient generated by the Slm causes two spin states to move in opposite directions, which can be regarded as a wave plate with a constant retardation and a continuously spatially varying fast axis in the direction of Φ / 2, which has different responses to two orthogonal circularly polarized states. When a linearly polarized light beam passes through the SLM, the propagation of the two spin states is dominated by ± Φ, respectively. During the propagation process, the spin state separation leads to PSHE, such as the spin-dependent focusing caused by the spherical phase, the spin separation of the helical phase Figure 6 ;

[0055] The spin shift generated by the vortex phase is as follows:

[0056]

[0057] where K= ;

[0058] and are the wave vectors of the two beams of light, respectively;

[0059] is a constant;

[0060] z represents the shift of the PSHE, and a specific Z is required to back-calculate the value of to obtain accurate PSHE control;

[0061] is the oscillation period, and the calculated optical axis distribution pattern of the PSHE is shown in Figure 6 , wherein Figure 5 is the theoretically calculated PSHE change generated by the vortex phase during axial propagation, and the black line and the gray line respectively represent the position change of the P light and the S light focusing points.

[0062] Figure 6 is a schematic diagram of the focusing of P and S lights of the PSHE generated by the spherical phase, and the two are focused at different axial positions

[0063] S5: detection and analysis

[0064] The light reflected by the spatial light modulator is obtained and divided into two beams of P light and S light, which are introduced into a charge coupled device for reception and detection and analysis, and the related characteristics of the photon spin Hall effect are detected and analyzed.

[0065] The laser exit spot diameter is 9mm, if it is less than 9mm, a beam expander is used to enlarge the spot, and the wavelength of the laser is 632.8nm.

[0066] The size of the polarization beam splitter is 10mm * 10mm * 10mm, and the material is optical glass with specific refractive index and extinction ratio, and the polarization state modulation is completed by the polarization beam splitter.

[0067] The phase delay accuracy of the quarter-wave plate is within 1 / 300λ, and the polarization direction can be accurately adjusted to 45°.

[0068] The spatial light modulator pixel size is 8um, the resolution is 1920*1200, the fill rate is greater than or equal to 90.7%, and the refresh rate is 60Hz. By loading a specific voltage distribution on the liquid crystal layer, different phase patterns are displayed, and the photon spin is modulated.

[0069] The charge-coupled device pixel size is 1.85um*1.85um, the resolution is 4032*3036, the pixel is 1200 million, the outer size is 35mm*35mm*8.6mm, the working temperature is 0-50°C, and the storage temperature is -30-70°C. The image acquisition algorithm is used to detect and analyze P light and S light, and the photon spin Hall effect related parameters can be calculated according to the light intensity distribution and spot shape characteristics.

[0070] A device for modulating photon spin using a spatial light modulator, comprising the following devices:

[0071] Laser: for generating an initial light beam, the exit spot has a specific diameter;

[0072] Polarization beam splitter: the size is 10mm*10mm*10mm, and the main function is to modulate the polarization state of the input light beam;

[0073] Quarter-wave plate: can adjust the polarization direction of the light after the polarization beam splitter;

[0074] Spatial light modulator (SLM): for example, produced by Benite Optical (Suzhou) Co., Ltd. SLMPAA380, which can adjust the internal horizontal arrangement of liquid crystal molecules according to the loading of different voltages, and modulate the photon spin by flexible modulation of the phase of the light beam, reflection or transmission operation;

[0075] Charge-coupled device (CCD): such as model Hikvision MV-CB120-10UM-S, used to receive the light reflected by the spatial light modulator and divided into P and S light, and detect and analyze it to obtain data information related to the photon spin Hall effect, assist in evaluating and researching the photon spin modulation.

[0076] The laser has an exit spot diameter of 9mm and a determined wavelength, such as 632.8nm, and when the exit spot diameter is less than 9mm, a beam expander can be provided to expand the spot size to the required size. The polarizing beam splitter is used in the device to modulate the polarization state of the light to be along the horizontal direction.

[0077] The quarter-wave plate is used in the device to adjust the polarization direction of the light to be 45° and to make the light enter the subsequent components with a suitable polarization state. The spatial light modulator has a specific pixel size of 8um, a resolution of 1920x1200, a fill factor greater than or equal to 90.7%, and a refresh rate of 60Hz.

[0078] The charge-coupled device has a pixel size of 1.85umx1.85um, a resolution of 4032x3036, 1200 million pixels, an outer size of 35mmx35mmx8.6mm, a working temperature range of 0-50°C, and a storage temperature range of -30-70°C.

[0079] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for modulating photon spin using a spatial light modulator, characterized in that, Includes the following steps: S1: Light emission step Turn on the laser to emit light; S2: Initial polarization modulation The light emitted from the laser is guided into a polarizing beam splitter, and the polarization state of the light is modulated to be horizontal through the polarizing beam splitter. S3: Polarization angle adjustment The light modulated by the polarizing beam splitter is passed through a quarter-wave plate, and the polarization direction of the light is adjusted to 40°-50°. S4: Spatial light modulation steps Light with a polarization direction of 40°-50° is introduced into a spatial light modulator. Depending on the model of the spatial light modulator, the light is reflected or transmitted within the spatial light modulator, and the phase of the light is modulated. S5: Detection and Analysis The light reflected by the spatial light modulator is acquired and split into two beams, P-beam and S-beam, which are then fed into a charge-coupled device for reception, detection, and analysis. The photon spin Hall effect is also detected and analyzed.

2. The method for modulating photon spin using a spatial light modulator according to claim 1, characterized in that, The laser emits a beam with a diameter of 9 mm and a wavelength of 600 nm to 650 nm.

3. The method for modulating photon spin using a spatial light modulator according to claim 1, characterized in that, The polarizing beam splitter has dimensions of 10mm * 10mm * 10mm and is made of optical glass. Polarization state modulation is achieved through the polarizing beam splitter.

4. The method for modulating photon spin using a spatial light modulator according to claim 1, characterized in that, The phase delay accuracy of the quarter-wave plate is within 1 / 300λ, and it can accurately adjust the polarization direction to 40°-50°.

5. A method for modulating photon spin using a spatial light modulator according to claim 1, characterized in that, The spatial light modulator has a pixel size of 8µm, a resolution of 1920 * 1200, a fill rate of ≥90.7%, and a refresh rate of 60Hz. It achieves the display of different phase patterns by loading different voltage distributions onto its liquid crystal layer, thereby modulating photon spin.

6. The method for modulating photon spin using a spatial light modulator according to claim 1, characterized in that, The charge-coupled device has a pixel size of 1.85um * 1.85um, a resolution of 4032 * 3036, 12 million pixels, and dimensions of 35mm × 35mm × 8.6mm. It operates at a temperature of 0 - 50°C and is stored at a temperature of -30 - 70°C. It uses an image acquisition algorithm to detect and analyze P- and S-beams and can calculate parameters related to the photon spin Hall effect based on factors including light intensity distribution and spot shape characteristics.

7. An apparatus for implementing the method of claim 1, comprising the following means: Laser: Used to generate the initial beam; Polarizing beam splitter: Its dimensions are 10mm×10mm×10mm, and it modulates the polarization state of the input beam. Quarter-wave plate: capable of adjusting the polarization direction of light after it has passed through a polarizing beam splitter; Spatial light modulator: It can adjust the internally horizontally arranged liquid crystal molecules according to different applied voltages, and perform reflection or transmission operations by flexibly modulating the phase of the light beam to modulate the photon spin. Charge-coupled devices (CCDs) are used to receive light reflected from a spatial light modulator and split into P and S beams, and to detect and analyze the light to obtain data related to the photon spin Hall effect, thereby assisting in the evaluation and research of photon spin modulation.

8. The apparatus for modulating photon spin using a spatial light modulator according to claim 7, characterized in that, The laser emits a beam with a diameter of 9 mm and a wavelength of 600 nm-650 nm. The polarizing beam splitter is used to modulate the polarization state of the light to be horizontal.

9. The apparatus for modulating photon spin using a spatial light modulator according to claim 7, characterized in that, The quarter-wave plate in this device is used to adjust the polarization direction of light to 40°-50°. The spatial light modulator has a pixel size of 8µm, a resolution of 1920×1200, a fill rate of ≥90.7%, and a refresh rate of 60Hz. Different phase patterns are displayed by loading different voltage distributions onto its liquid crystal layer, thereby modulating photon spin.

10. The apparatus for modulating photon spin using a spatial light modulator according to claim 7, characterized in that, The charge-coupled device has a pixel size of 1.85um×1.85um, a resolution of 4032×3036, 12 million pixels, and dimensions of 35mm×35mm×8.6mm. It operates in a temperature range of 0-50°C and is stored in a temperature range of -30-70°C.

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