Method for modulating photon spinning by using spatial light modulator

Abstract

The invention relates to the technical field of spatial light modulators, and discloses a method for modulating photon spinning by using a spatial light modulator, which comprises the following steps: S1, a light emitting step: emitting light, S2, initial polarization modulation, S3, initial polarization modulation, and S4, initial polarization modulation. The polarization state of light is modulated to be in the horizontal direction through the polarization splitting prism, S3, polarization angle adjustment, S4, spatial light modulation, and S5, detection and analysis. According to the invention, the spatial light modulator is adopted to flexibly modulate the phase so as to control and generate different types of PHSEs. A polarized light beam passing through the spatial light modulator can be modulated by designing different phases generated on the spatial light modulator, so that if circular polarization components need to be separated from each other and move along a predefined track, the circular polarization components can be realized by modulating the phases of the spatial light modulator. Therefore, the photon spin Hall effect and the device relying on the photon spin Hall effect can be simply and flexibly regulated and controlled by the spatial light modulator.

Description

Technical Field

[0001] The invention relates to the technical field of household kitchens, and in particular to a method for modulating photon spin using a spatial light modulator. Background Art

[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 an external signal 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 precisely controlled to generate a three-dimensional holographic image. In an adaptive optical system, it can change the wavefront of light in real time according to the feedback information from the wavefront sensor, correct the aberration of the optical system, and improve the imaging quality.

[0003] The SOI of light can be greatly enhanced by the polarization-transformation-related (Pancharatnam–Berry, PB) phase. Due to the SOI induced by the PB phase, a large number of different ways of independent photon separation have been proposed. These are considered to be different types of PHSEs, which are mainly designed or discovered based on the propagation of spin states. For example, the linear phase gradient produced by the polarization grating causes the two spin states to shift in opposite directions, while the spherical phase leads to spin-dependent focusing. Combined with the phase structure of the spatially structured beam, the PB phase can produce 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 adjust the propagation direction of light, realize new optical devices and optical signal processing. In addition, the photon spin Hall effect is also in topological Φ. It should be pointed out that the photon spin Hall effect is a relatively new research field, which is still under in-depth research and exploration, and there are still many problems and challenges to be solved. Among them, the most urgent is that although the photon spin Hall effect can be controlled, it is often achieved by changing the gradient refractive index or by using variable refractive index materials. This means that PSHE cannot be simply and flexibly controlled. Summary of the invention

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

[0006] To achieve the above objectives, the present invention is implemented by the following technical solution: A method for modulating photon spin using a spatial light modulator, comprising the following steps:

[0007] S1: Light emission step

[0008] Start the laser to emit light;

[0009] S2: Initial polarization modulation

[0010] Directing the light emitted by the laser into a polarization beam splitter prism, and modulating the polarization state of the light to be in a horizontal direction through the polarization beam splitter prism;

[0011] S3: Polarization Angle Adjustment

[0012] Passing the light modulated by the PBS through a quarter wave plate to adjust the polarization direction of the light to 45°;

[0013] S4: Spatial Light Modulation Step

[0014] Directing light with a polarization direction of 45° into a spatial light modulator, and depending on the model of the spatial light modulator, causing the light to be reflected or transmitted in the spatial light modulator, and modulating the phase of the light;

[0015] S5: Detection Analysis

[0016] The light reflected by the spatial light modulator is obtained and divided into two beams, P light and S light, which are introduced into a charge coupled device for reception, detection and analysis, and the relevant characteristics of the photon spin Hall effect are detected and analyzed.

[0017] Preferably, the diameter of the laser output spot is 9 mm. If it is less than 9 mm, a beam expander is used to expand the spot. The wavelength of the laser is 632.8 nm.

[0018] Preferably, the size of the polarization beam splitter prism is 10 mm*10 mm*10 mm, and the material thereof is optical glass with a specific refractive index and extinction ratio, and polarization state modulation is completed by 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%, a refresh rate of 60Hz, and displays different phase patterns by loading a specific voltage distribution on its liquid crystal layer to modulate photon spin.

[0021] Preferably, the charge coupled device has a pixel size of 1.85um*1.85um, a resolution of 4032*3036, 12 million pixels, an outer dimension of 35mm×35mm×8.6mm, an operating temperature of 0-50°C, and a storage temperature of -30-70°C. It uses an image acquisition algorithm to detect and analyze P light and S light, and can calculate parameters related to the photon spin Hall effect based on characteristics including light intensity distribution and spot shape.

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

[0023] Laser: Used to generate an initial light beam with an output spot of a specific diameter.

[0024] Polarization beam splitter: Its size is 10mm×10mm×10mm, and its main function is to modulate the polarization state of the input light beam;

[0025] Quarter wave plate: can adjust the polarization direction of light after passing through PBS;

[0026] Spatial light modulator: It can adjust the horizontally arranged liquid crystal molecules inside according to the different voltages loaded, and flexibly modulate the phase of the light beam to perform reflection or transmission operations to modulate the photon spin.

[0027] Charge-coupled device: used to receive the light reflected by the SLM and divided into two beams, P and S, and detect and analyze it to obtain data information related to the photon spin Hall effect, and assist in the evaluation and research of photon spin modulation.

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

[0029] Preferably, the quarter wave plate is used in the present device to adjust the polarization direction of light to 45° and allow the light to enter subsequent components in a suitable polarization state, and 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 has a pixel size of 1.85um×1.85um, a resolution of 4032×3036, 12 million pixels, an external dimension of 35mm×35mm×8.6mm, an operating temperature range of 0-50°C, and a storage temperature range of -30-70°C.

[0031] The present invention provides a method for modulating photon spin using a spatial light modulator. The method has the following beneficial effects:

[0032] 1. The present invention uses a spatial light modulator 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 the 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 devices based on the photon spin Hall effect can be simply and flexibly controlled by the spatial light modulator.

[0033] 2. The present invention configures a complete optical path system composed of relevant optical elements, such as a polarization beam splitter prism (PBS), a quarter wave plate (QWP), a spatial light modulator (SLM) and a charge coupled device (CCD). After a series of modulation operations on the photon spin, the CCD receives, detects and analyzes the P light and S light reflected and separated by the SLM modulation, thereby accurately obtaining relevant data information of the photon spin modulation, which is helpful for in-depth research on the relevant characteristics of the photon spin Hall effect and feedback optimization of the entire modulation process, further improving the accuracy and effect of the regulation.

[0034] 3. The present invention can produce a variety of unique light manipulation effects by means of the design and loading of different phases such as vortex phase and spherical phase factor. For example, the vortex phase can produce a specific spin offset, and its optical axis distribution pattern shows an oscillating spin-related offset; the spherical phase can lead to a spin-related focusing effect. This provides more diverse means for the optical field in terms of light propagation direction control, new optical device development, and optical signal processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A flow chart of a method for modulating photon spin using a spatial light modulator;

[0036] Figure 2 Schematic diagram of photon spin of the present invention;

[0037] Figure 3 It is the optical path design diagram of the present invention;

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

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

[0040] Figure 6 A schematic diagram of the spin-related shift of the oscillations generated by the vortex phase of the present invention;

[0041] Figure 7 Schematic diagram of photon spin correlation focusing generated by the spherical phase of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Example:

[0044] Please see attached Figure 1 - Attachment Figure 7 , an embodiment of the present invention provides a method for modulating photon spin using a spatial light modulator, comprising the following steps:

[0045] S1: Light emission step

[0046] Start the laser to emit light;

[0047] S2: Initial polarization modulation

[0048] Directing the light emitted by the laser into a polarization beam splitter prism, and modulating the polarization state of the light to be in a horizontal direction through the polarization beam splitter prism;

[0049] S3: Polarization Angle Adjustment

[0050] Passing the light modulated by the PBS through a quarter wave plate to adjust the polarization direction of the light to 45°;

[0051] S4: Spatial Light Modulation Step

[0052] Directing light with a polarization direction of 45° into a spatial light modulator, and depending on the model of the spatial light modulator, causing the light to be reflected or transmitted in the spatial light modulator, and modulating the phase of the light;

[0053] The phase diagram needs to be designed during the process, e.g. Figure 4 The vortex phase and Figure 5 The oscillating PSHE generated by the medium spherical phase factor can take on more different forms through the spin-dependent separation of Lcos;

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

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

[0056] Z=Φ(r) * Δk r (cos(X)x+sin(X)y) / 4r

[0057] in

[0058] k0 and k r are the wave vectors of the two light beams respectively;

[0059] Δ is a constant;

[0060] z represents the offset of PSHE, and a specific Z is needed to infer the value of Φ(r) to obtain accurate PSHE control;

[0061] Λ is the oscillation period. According to the equation, the optical axis distribution pattern of PSHE is calculated as Figure 6 As shown in Figure 5 That is, the theoretically calculated PSHE change caused by the vortex phase during axial propagation. The black line and gray line represent the position changes of the offset focus of P light and S light, respectively.

[0062] Figure 6 This is a schematic diagram of the focusing of the P and S light of the PSHE generated by the spherical phase. The two are focused on different axes.

[0063] S5: Detection Analysis

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

[0065] The diameter of the laser output spot is 9 mm. If it is less than 9 mm, a beam expander is used to expand the spot. The wavelength of the laser is 632.8 nm.

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

[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 has a pixel size of 8um, a resolution of 1920*1200, a filling rate greater than or equal to 90.7%, and a refresh rate of 60Hz. By loading a specific voltage distribution on its liquid crystal layer, it realizes the display of different phase patterns and modulates the photon spin.

[0069] The charge coupled device has a pixel size of 1.85um*1.85um, a resolution of 4032*3036, 12 million pixels, an external dimension of 35mm×35mm×8.6mm, an operating temperature of 0-50°C, and a storage temperature of -30-70°C. It uses an image acquisition algorithm to detect and analyze P light and S light, and can calculate parameters related to the photon spin Hall effect based on characteristics including light intensity distribution and light spot shape.

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

[0071] Laser: Used to generate an initial light beam with an output spot of a specific diameter.

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

[0073] Quarter wave plate: can adjust the polarization direction of light after passing through PBS;

[0074] Spatial light modulator (SLM): For example, the SLMPAA380 produced by Bennett Optics (Suzhou) Co., Ltd. can adjust the horizontally arranged liquid crystal molecules inside according to the different voltages loaded, and flexibly modulate the phase of the light beam to perform reflection or transmission operations to modulate the photon spin.

[0075] Charge-coupled device (CCD): such as the Hikvision MV-CB120-10UM-S, which is used to receive the light reflected by the SLM and divided into two beams, P and S light, and detect and analyze it to obtain data information related to the photon spin Hall effect, and assist in the evaluation and research of photon spin modulation.

[0076] The laser output spot diameter is 9mm and has a certain wavelength, such as 632.8nm. When the output 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 is used in this device to modulate the polarization state of light to be in the horizontal direction.

[0077] The quarter wave plate is used in the present device to adjust the polarization direction of light to 45° and allow the light to enter subsequent components in a suitable 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.

[0078] The charge coupled device has a pixel size of 1.85um×1.85um, a resolution of 4032×3036, 12 million pixels, an external dimension of 35mm×35mm×8.6mm, an operating temperature range of 0-50°C, and a storage temperature range of -30-70°C.

[0079] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention 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: The following steps are involved: S1: Light emission step Start the laser to emit light; S2: Initial polarization modulation Directing the light emitted by the laser into a polarization beam splitter prism, and modulating the polarization state of the light to be in a horizontal direction through the polarization beam splitter prism; S3: Polarization Angle Adjustment Passing the light modulated by the PBS through a quarter wave plate to adjust the polarization direction of the light to 40°-50°; S4: Spatial Light Modulation Step Directing light with a polarization direction of 40°-50° into a spatial light modulator, and depending on the model of the spatial light modulator, causing the light to be reflected or transmitted in the spatial light modulator, and modulating the phase of the light; S5: Detection Analysis The light reflected by the spatial light modulator is obtained and divided into two beams, P light and S light, which are introduced into a charge coupled device for reception, detection and analysis, and the relevant characteristics of the photon spin Hall effect are detected and analyzed.

2. The method for modulating photon spin using a spatial light modulator according to claim 1, characterized in that: The diameter of the laser output spot is 9 mm. If it is less than 9 mm, a beam expander is used to expand the spot. The wavelength of the laser is 600nm-650nm.

3. The method for modulating photon spin using a spatial light modulator according to claim 1, characterized in that: The size of the polarization beam splitter prism is 10mm*10mm*10mm, and its material is optical glass with a specific refractive index and extinction ratio, and polarization state modulation is completed through the polarization beam splitter prism.

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 the polarization direction can be accurately adjusted to 40°-50°.

5. The 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 8um, a resolution of 1920*1200, a filling rate greater than or equal to 90.7%, and a refresh rate of 60Hz. By loading a specific voltage distribution on its liquid crystal layer, it realizes the display of different phase patterns and modulates the 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, an external dimension of 35mm×35mm×8.6mm, an operating temperature of 0-50°C, and a storage temperature of -30-70°C. It uses an image acquisition algorithm to detect and analyze P light and S light, and can calculate parameters related to the photon spin Hall effect based on characteristics including light intensity distribution and light spot shape.

7. The device for modulating photon spin using a spatial light modulator according to claim 1, comprising the following devices: Laser: Used to generate an initial light beam with an output spot of a specific diameter. Polarization beam splitter: Its size is 10mm×10mm×10mm, and its main function is to modulate the polarization state of the input light beam; Quarter wave plate: can adjust the polarization direction of light after passing through PBS; Spatial light modulator: It can adjust the horizontally arranged liquid crystal molecules inside according to the different voltages loaded, and flexibly modulate the phase of the light beam to perform reflection or transmission operations to modulate the photon spin. Charge-coupled device: used to receive the light reflected by the SLM and divided into two beams, P and S, and detect and analyze it to obtain data information related to the photon spin Hall effect, and assist in the evaluation and research of photon spin modulation.

8. The method for modulating photon spin using a spatial light modulator according to claim 7, characterized in that: The laser output spot diameter is 9mm and has a certain wavelength, including 600nm-650nm. When the output 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 is used in this device to modulate the polarization state of light to be in the horizontal direction.

9. The method for modulating photon spin using a spatial light modulator according to claim 7, characterized in that: The quarter wave plate is used in the present device to adjust the polarization direction of light to 40°-50° and allow the light to enter subsequent components in a suitable 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.

10. The method 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, an external dimension of 35mm×35mm×8.6mm, an operating temperature range of 0-50°C, and a storage temperature range of -30-70°C.

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