A complex amplitude light field control device and its use method

Abstract

The present invention discloses a complex-amplitude light field control device and a method for using the same, relating to the field of spatial light modulation technology. The device comprises a first transmission-type modulation device having a sandwich multi-layer structure consisting of a glass upper substrate, a liquid crystal layer and a pixel electrode, and an upper surface polarizer and a lower surface polarizer are provided on the upper and lower surfaces, respectively. The polarization direction of the upper surface polarizer is consistent with the polarization direction of the incident light, and the polarization direction of the lower surface polarizer is perpendicular to the polarization direction of the incident light. In the present invention, through the effective combination of transmission-type and reflection-type modulation devices, the liquid crystal spatial light modulator is utilized to finely control the light beam, and the incident light field is modulated with multiple degrees of freedom and high precision such as amplitude, phase and polarization, thereby greatly improving the light field control method and reducing the hologram calculation iteration time. The device can be applied to multiple fields such as holographic display, all-optical communication, and laser processing.

Description

Technical Field

[0001] The present invention relates to the technical field of spatial light modulation, and in particular to a complex amplitude light field control device and a method for using the same. Background Art

[0002] Light field manipulation technology utilizes spatial light modulators (SLMs) to generate novel light field distributions with spatially nonuniform amplitude, phase, and polarization. This technology holds broad application prospects in a variety of fields, including holographic displays, all-optical communications, and beam shaping. SLMs require real-time dynamic control and digital encoding capabilities, thus modulating the wavefront of light waves at different locations through pixelation.

[0003] Currently, two main types of spatial light modulators are used for spatial light field manipulation: digital micromirrors (DMDs), which enable amplitude modulation, and liquid crystal on silicon (LCoS), which enable phase modulation. DMD devices, based on MEMS technology, consist of an array of multiple micromirrors. Each micromirror can be deflected by applying a voltage, and the amplitude is controlled by the speed of deflection. They offer advantages such as fast modulation speed, high reflectivity, and a high damage threshold. LCoS devices achieve phase modulation through the deflection of liquid crystal molecules and have high diffraction efficiency. They can be used in wavelength selective switches in optical communication backbone networks, as well as in technologies such as invisible cutting and spot shaping in laser processing. However, these spatial light modulators can only achieve single phase or amplitude modulation, which limits the ability to manipulate complex light fields. Simultaneously achieving complex amplitude and phase modulation is crucial for applications such as holographic displays.

[0004] In order to achieve simultaneous amplitude and phase control in a spatial light modulator, existing technologies usually use a specific encoding algorithm to include the amplitude and phase information of the target light field distribution in a computational hologram. By combining multiple pixels, phase modulation can be achieved in an amplitude-type device, or amplitude modulation can be achieved in a phase-type device. However, this method not only sacrifices resolution, but also involves complex holographic algorithm processing, which is inefficient. Other solutions use a cascade of multiple spatial light modulators. The entire optical module is large, which limits its application to more types of complex light fields.

[0005] In order to solve the problems of low efficiency, complex optical path, and poor adaptability in existing complex amplitude light field modulation technology, the present invention provides a design scheme for a light field modulation device based on the combination of liquid crystal and beam splitter, which can independently control the amplitude, phase and polarization of the incident light. Summary of the Invention

[0006] The object of the present invention is to provide a complex amplitude light field control device and a method of using the same to solve the problems raised in the above background technology.

[0007] To solve the above technical problems, the present invention provides a complex amplitude light field control device, comprising:

[0008] A first transmissive modulation device having a sandwich multilayer structure consisting of a glass upper substrate, a liquid crystal layer, and pixel electrodes, and provided with an upper surface polarizer and a lower surface polarizer on its upper and lower surfaces, respectively. The polarization direction of the upper surface polarizer is consistent with the polarization direction of the incident light, and the polarization direction of the lower surface polarizer is perpendicular to the polarization direction of the incident light;

[0009] Reflective modulation device, using liquid crystal on silicon LCOS structure;

[0010] The first beam splitter, the second beam splitter, the third beam splitter and the fourth beam splitter are all polarization-independent beam splitting devices, and the materials thereof are transparent glass materials at the applied wavelength;

[0011] The first quarter wave plate, the second quarter wave plate, the third quarter wave plate and the fourth quarter wave plate are used to precisely modulate the polarization state of the incident light;

[0012] A first dielectric layer is provided between the first beam splitter and the reflective modulation device;

[0013] The second dielectric layer is arranged between the second beam splitter and the reflective modulation device.

[0014] Furthermore, the first transmission modulation device is fixed on the upper surface of the first beam splitter.

[0015] Furthermore, the reflective modulation device is fixed below the third beam splitter and the fourth beam splitter.

[0016] Furthermore, the optical path difference between the first transmissive modulation device and the reflective modulation device is in a near-field range of <5 cm.

[0017] Furthermore, the complex amplitude light field control device is coated with an anti-reflection thin film coating on both the glass and air interfaces.

[0018] Furthermore, the thickness of the first dielectric layer is equal to the thickness of the first quarter-wave plate.

[0019] Furthermore, the thickness of the second dielectric layer is equal to the sum of the thicknesses of the fourth quarter wave plate and the bottom polarizer. The bottom polarizer is arranged on the upper surface of the right half SLM of the reflective modulator. Its polarization direction is consistent with the optical axis direction of the liquid crystal molecules in the reflective modulator, and is used to maintain the compact structure of the device.

[0020] A method for using a complex-amplitude light field control device, comprising:

[0021] First design:

[0022] The incident light is guided to enter the first transmissive modulator after being expanded and collimated. The arrangement of the liquid crystal molecules is controlled by changing the voltage applied to the liquid crystal layer of the first transmissive modulator, thereby using the orthogonal polarizers on the upper and lower surfaces to achieve amplitude modulation of the incident light and generate a transmitted light field.

[0023] The transmitted light field passes through the first beam splitter and is irradiated onto the left half of the reflective modulator SLM, which is used to modulate the phase of the incident light and generate a reflected light field. The polarization direction of the transmitted light field remains parallel to the optical axis direction of the liquid crystal molecules in the reflective modulator;

[0024] The reflected light field passes through the first beam splitter and the second beam splitter in sequence and reaches the right half of the reflective modulator SLM. The light field is polarized and modulated by the first quarter-wave plate set on the surface of the SLM to produce the final reflected light field. The fast axis direction of the first quarter-wave plate forms a specific angle with the optical axis direction of the liquid crystal molecules in the reflective modulator.

[0025] The reflected light field is transmitted through the second beam splitter to achieve independent control of amplitude, phase, and polarization. The first transmissive modulator and the reflective modulator share a common drive control. Based on specific application requirements, a hologram is generated using a holographic algorithm and loaded onto the first transmissive and reflective modulators. Based on the target light field phase distribution, the phase of the left half of the reflective modulator is used to compensate for the additional phase caused by amplitude and polarization modulation.

[0026] Second design:

[0027] Given that the pixel size of the first transmissive modulator is several times that of the reflective modulator, and that polarization distribution is relatively less important in certain application scenarios, the reflective modulator is used to modulate the amplitude and phase of the light field, while the second transmissive modulator is used to modulate the polarization of the light field.

[0028] The incident light is guided to be expanded and collimated, and then passes through the second beam splitter to be incident on the left half of the reflective modulator SLM for phase modulation and generates a reflected light field. The polarization direction of the incident light remains parallel to the optical axis direction of the liquid crystal molecules in the reflective modulator;

[0029] The reflected light field passes through the third beam splitter and the fourth beam splitter in sequence and reaches the right half SLM of the reflective modulator. It is amplitude modulated by the fourth quarter-wave plate and the bottom polarizer arranged on the surface of the reflective modulator to generate a reflected light field. The fast axis direction of the fourth quarter-wave plate forms a specific angle with the optical axis direction of the liquid crystal molecules in the reflective modulator.

[0030] The reflected light field is transmitted through the fourth beam splitter to the second transmission modulator for polarization modulation and emission. This is achieved by arranging a second 1 / 4 wave plate and a third 1 / 4 wave plate on the upper and lower surfaces of the second transmission modulator. The fast axis directions of the fourth 1 / 4 wave plate are perpendicular to each other. The optical axis direction of the liquid crystal molecules in the second transmission modulator forms a specific angle with the fast axis direction of the fourth 1 / 4 wave plate. The SLM phase modulation of the reflective modulator is used to compensate for the amplitude of the light field and the additional phase generated by the polarization modulation.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] By utilizing the fine modulation characteristics of the spatial light modulator on the light beam and combining the compact structure and small size of the beam splitter, a light field complex amplitude control device that independently controls the amplitude, phase and polarization is proposed. It can meet the needs of various applications and realize the miniaturization and standardization of processing modules. It is a highly efficient and widely applicable spatial light modulation technology.

[0033] By effectively combining transmissive and reflective modulators, and leveraging the precise control of light beams by liquid crystal spatial light modulators, the incident light field is modulated with high precision using multiple degrees of freedom, including amplitude, phase, and polarization. This significantly improves light field control methods and reduces hologram calculation iteration time. This technology has applications in a variety of fields, including holographic displays, all-optical communications, and laser processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the overall structure of a complex amplitude light field control device and its use method of the present invention;

[0035] Figure 2 This is a schematic diagram of a first optical path design in a complex amplitude light field control device and a method of using the same according to the present invention;

[0036] Figure 3 This is a schematic diagram of a second optical path design in a complex amplitude light field control device and a method of using the same according to the present invention;

[0037] Figure 4 This is a diagram of light field control in a complex-amplitude light field control device and its use method of the present invention.

[0038] In the picture:

[0039] 101. First transmission modulator; 1011. Upper surface polarizer; 1012. Lower surface polarizer; 102. First beam splitter; 103. LCOS modulator; 104. First dielectric layer; 105. Second beam splitter; 106. First quarter wave plate; 201. Reflective modulator; 202. Second transmission modulator; 2021. Second quarter wave plate; 2022. Third quarter wave plate; 203. Third beam splitter; 204. Fourth beam splitter; 205. Fourth quarter wave plate; 206. Bottom polarizer; 207. Second dielectric layer. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0041] See also Figures 1-4 , the present invention provides a technical solution:

[0042] See Figures 1-4 As shown, an embodiment of a complex amplitude light field control device and a method of using the same:

[0043] A complex amplitude light field control device:

[0044] A first transmission modulator 101, a reflection modulator 201, a first beam splitter 102, a second beam splitter 105, a third beam splitter 203, a fourth beam splitter 204, a first quarter wave plate 106, a second quarter wave plate 2021, a third quarter wave plate 2022, a fourth quarter wave plate 205, an upper surface polarizer 1011, a lower surface polarizer 1012, a bottom polarizer 206, a first dielectric layer 104 and a second dielectric layer 207.

[0045] The first transmissive modulator 101 has a multi-layer sandwich structure consisting of a glass upper substrate, a liquid crystal layer, and pixel electrodes. It is fixed to the upper surface of the first beam splitter 102, and features a pair of orthogonal polarizers: an upper polarizer 1011 and a lower polarizer 1012. The upper polarizer 1011 aligns with the polarization direction of the incident light, while the lower polarizer 1012 is perpendicular to it. By varying the voltage applied to the liquid crystal layer, the arrangement of the liquid crystal molecules is controlled, thereby modulating the intensity of the incident light and achieving amplitude modulation.

[0046] The first beam splitter 102, the second beam splitter 105, the third beam splitter 203 and the fourth beam splitter 204 are all polarization-independent beam splitting devices, and like the first 1 / 4 wave plate 106, the second 1 / 4 wave plate 2021, the third 1 / 4 wave plate 2022 and the fourth 1 / 4 wave plate 205, they are all made of transparent glass materials at the applied wavelength.

[0047] The reflective modulation device 201 uses liquid crystal on silicon (LCOS) and is fixed below the third beam splitter 203 and the fourth beam splitter 204. It is divided into two parts SLM1 and SLM2 of equal size by the beam splitter and is mainly used to modulate the phase of the incident light.

[0048] The first quarter-wave plate 106, the second quarter-wave plate 2021, the third quarter-wave plate 2022, and the fourth quarter-wave plate 205 are used to precisely modulate the polarization state of the incident light. Furthermore, to facilitate hologram calculation and calibration, the optical path difference between the first transmissive modulator 101 and the reflective modulator 201 is within the near-field range (<5 cm). Furthermore, the complex-amplitude optical field manipulation device is coated with anti-reflection thin films at both the glass and air interfaces.

[0049] A first design of a method for using a complex amplitude light field control device:

[0050] After beam expansion and collimation, the incident light is incident on the first transmissive modulator 101, where it undergoes amplitude modulation and generates a transmitted light field. A pair of orthogonal polarizers are placed on the upper and lower surfaces of the first transmissive modulator 101. The orientation of the upper polarizer 1011 aligns with the polarization direction of the incident light, while the orientation of the lower polarizer 1012 is perpendicular to the polarization direction of the incident light. A voltage applied to the liquid crystal layer controls the arrangement of the liquid crystal molecules, thereby varying the intensity modulation of the incident light by the transmissive modulator. The Jones vector expression for the transmitted light field is:

[0051]

[0052] Where A1(x,y) is the amplitude of the target light field after modulation, is the additional phase modulation produced by the liquid crystal layer and is related to A1(x,y).

[0053] After passing through the first beam splitter 102, the transmitted light field E1 is irradiated onto the left half SLM1 of the LCOS modulator 103 for phase modulation, generating a reflected light field. To maintain the compactness and stability of the device, a first dielectric layer 104 is sandwiched between the first beam splitter 102 and the LCOS modulator 103. Its thickness is the same as that of the first quarter-wave plate 106. The polarization direction of the transmitted light field remains parallel to the optical axis of the liquid crystal molecules in the LCOS. The Jones vector of the reflected light field E2 is expressed as:

[0054]

[0055] In the formula It is the phase modulation generated by the left half SLM1 of the LCOS modulation device 103.

[0056] The reflected light field E2 passes through the first beam splitter 102 and the second beam splitter 105 before reaching the right half SLM2 of the LCOS modulator 103 for polarization modulation, generating a reflected light field. A first quarter-wave plate 106 is fixed to the upper surface of the right half SLM2 of the LCOS modulator 103. The fast axis of the first quarter-wave plate 106 forms an angle with the optical axis of the liquid crystal molecules in the LCOS modulator 103. The Jones vector of the resulting reflected light field E3 is expressed as:

[0057]

[0058] In the formula In addition to the phase modulation generated by the right half SLM2 of the LCOS modulation device 103, the polarization modulation of the light field will generate additional phase modulation.

[0059] The reflected light field is transmitted through the second beam splitter 105, enabling independent control of amplitude, phase, and polarization. The first transmissive modulator 101 and the LCOS modulator 103 share a common drive control, controlling the liquid crystal deflection angle via a voltage signal. Based on specific application requirements, a holographic algorithm is used to generate a hologram and load it onto the transmissive and reflective modulators. Based on the target light field phase distribution, the phase loaded onto the left half of the LCOS modulator 103 can be used to compensate for the additional phase introduced by amplitude and polarization modulation.

[0060] A second design of a method for using a complex-amplitude light field control device:

[0061] Since the pixel size of the first transmissive modulator 101 is several times that of the LCOS modulator 103, the polarization distribution is less important than the amplitude and phase distribution of the target light field. Therefore, the reflective modulator 201 is used to modulate the amplitude and phase of the light field, and the second transmissive modulator 202 is used to modulate the polarization of the light field. After the incident light is expanded and collimated, it passes through the third beam splitter 203 and is incident on the left half SLM1 of the reflective modulator 201 for phase modulation and generates a reflected light field. The polarization direction of the incident light remains parallel to the optical axis direction of the liquid crystal molecules in the reflective modulator 201. The Jones vector expression of the reflected light field is:

[0062]

[0063] In the formula It is the phase modulation generated by the left half SLM1 of the reflective modulation device 201.

[0064] The reflected light field E′1 passes through the third beam splitter 203 and the fourth beam splitter 204 in sequence and then reaches the right half SLM2 of the reflective modulator 201 for amplitude modulation to generate the reflected light field E'2. The fourth quarter wave plate 205 and the bottom polarizer 206 are fixed on the upper surface of the right half SLM2 of the reflective modulator 201. In order to keep the device compact and stable, a second dielectric layer is sandwiched between the third beam splitter 203 and the reflective modulator 201, and its thickness is the same as the sum of the thicknesses of the fourth quarter wave plate 205 and the bottom polarizer 206. The fast axis direction of the fourth quarter wave plate 205 is at an angle to the optical axis direction of the liquid crystal molecules in the LCOS, and the direction of the bottom polarizer 206 is consistent with the optical axis direction of the liquid crystal molecules in the LCOS. The Jones vector expression of the obtained reflected light field E'2 is:

[0065]

[0066] In the formula It is the phase modulation generated by the right half SLM2 of the reflective modulation device 201.

[0067] The reflected light field E3 passes through the fourth beam splitter 204 and is transmitted to the second transmissive modulator 202 for polarization modulation before being emitted. A second quarter-wave plate 2021 and a third quarter-wave plate 2022 are fixed to the upper and lower surfaces of the second transmissive modulator 202, respectively. The fast axis of the fourth quarter-wave plate 205 is perpendicular to each other, and the optical axis of the liquid crystal molecules in the second transmissive modulator 202 forms an angle with the fast axis of the fourth quarter-wave plate 205.

[0068] The Jones vector expression of the transmitted light field is finally obtained as follows:

[0069]

[0070] In the formula In addition to the phase modulation generated by the second transmissive modulation device 202 , the amplitude and polarization modulation of the light field will generate additional phase modulation, which can be compensated by the phase modulation of the SLM1 .

[0071] Summarize:

[0072] A complex-amplitude light field control architecture integrating multiple optical components has been constructed, breaking through the technical bottleneck that traditional light field modulation devices can only achieve single amplitude or phase modulation, and successfully realizing independent, precise and dynamic control of light field amplitude, phase and polarization, providing a new solution for the generation and application of complex light fields, greatly expanding the dimension and flexibility of light field control, and meeting the stringent requirements of cutting-edge fields such as optical encryption and quantum communication for complex light fields.

[0073] A precise compensation mechanism for the additional phase generated by amplitude and polarization modulation has been developed. Through reasonable optical layout and precise algorithmic control, the additional phase introduced by amplitude and polarization modulation can be accurately and in real time during the light field modulation process. This effectively overcomes the light field distortion and error problems caused by the accumulation of additional phase in traditional light field control methods, significantly improves the accuracy and stability of light field control, and ensures the integrity and reliability of the light field during transmission and application. This provides solid technical support for high-precision light field applications such as high-resolution holographic display and precision optical measurement.

[0074] Through the optimized selection, precise layout, and parameter matching of each optical component, the device was successfully standardized and miniaturized. Compared to the traditional cascaded multi-chip spatial light modulator approach, this invention significantly reduces the number and volume of optical components, lowering system complexity and manufacturing costs while improving the stability and reliability of the device. The standardized design makes the device easier to integrate into various optical systems, while its miniaturization broadens its application range in space-constrained environments, such as miniature optical communication terminals and portable optical detection equipment, effectively promoting the popularization and application of light field manipulation technology in more fields.

[0075] Amplitude modulation: Through a unique combination of liquid crystal layer voltage regulation and orthogonal polarizers, combined with the ingenious design of specific wave plates and polarizers, ultra-fine control of the light field amplitude is achieved. In the field of holographic display, this high-precision amplitude modulation capability can make holographic images present more delicate and realistic light and dark contrast effects, significantly improving the visual quality and viewing experience of the image. In the field of laser processing, the energy distribution of the light spot can be precisely customized, achieving efficient and precise processing of the processing material, effectively improving processing accuracy and product quality, reducing scrap rate, and thus significantly improving production efficiency and economic benefits.

[0076] Phase modulation: In both designs, the light field is precisely phase-controlled down to the subwavelength level. In holographic displays, this significantly improves the accuracy and clarity of holographic image reproduction, enabling richer detail and a more three-dimensional feel, as if the object were actually there. In all-optical communications, precise phase control can effectively reduce distortion and bit error rates during optical signal transmission, significantly improving the transmission capacity and reliability of communication systems. This will meet the future demands for high-speed, high-capacity optical communications and propel optical communications technology to new heights.

[0077] Polarization modulation: Near-perfect control of the polarization state of the light field is achieved. In polarized optical communications, this high-precision polarization modulation capability can greatly enhance the confidentiality and anti-interference capabilities of communications, ensuring the security and integrity of information during transmission. In the field of optical imaging, it can effectively improve image contrast and clarity, allowing for the clear presentation of tiny details and weak signals. This provides more accurate and reliable image information for fields such as medical diagnosis and materials science research, facilitating the precise implementation of scientific research and clinical work.

[0078] In terms of overall device performance: Through optimized structural design, the device has been successfully standardized and miniaturized, overcoming the drawbacks of traditional light field manipulation devices, such as bulk, complex structure, and difficulty in integration. This not only improves the practicality and stability of the device, enabling it to be more easily integrated into various complex light field manipulation systems, but also significantly reduces hologram calculation iteration time, improving the efficiency and response speed of light field manipulation. Furthermore, the miniaturized and standardized design reduces the manufacturing cost, power consumption, and maintenance difficulty of the device, resulting in significant economic and social benefits. This lays a solid foundation for the widespread application and popularization of light field manipulation technology in more fields, and is expected to promote the upgrading and development of related industries, creating greater market value and application prospects.

Claims

1. A complex amplitude light field control device, characterized in that: include: A first transmission-type modulation device (101) has a sandwich multilayer structure consisting of a glass upper substrate, a liquid crystal layer, and pixel electrodes, and is provided with an upper surface polarizer (1011) and a lower surface polarizer (1012) on its upper and lower surfaces, respectively, wherein the polarization direction of the upper surface polarizer (1011) is consistent with the polarization direction of the incident light, and the polarization direction of the lower surface polarizer (1012) is perpendicular to the polarization direction of the incident light; A reflective modulation device (103) adopts a silicon-based liquid crystal structure, wherein the left half SLM1 and the right half SLM2 correspond to the first beam splitter (102) and the second beam splitter (105), respectively; The first transmission modulator (101) is located at the light incident surface of the first beam splitter (102), and the upper and lower surfaces thereof are provided with an upper surface polarizer (1011) and a lower surface polarizer (1012), respectively; the light exit surface of the first beam splitter (102) corresponds to the light incident surface of the second beam splitter (105); the reflection modulator (103) is located above the first dielectric layer (104) and adjacent to the side surface of the first beam splitter (102); the reflection modulator (103) is divided into a left half SLM1 and a right half SLM2 by the first beam splitter (102) and the second beam splitter (105); The first beam splitter (102) and the second beam splitter (105) are both polarization-independent beam splitting devices, and the first transmission-type modulation device (101) is fixed on the upper surface of the first beam splitter (102); A first quarter wave plate (106) is arranged between the second beam splitter (105) and the right half SLM2 of the reflective modulation device (103); The first dielectric layer (104) is arranged between the first beam splitter (102) and the left half SLM1 of the reflective modulation device (103), and its thickness is equal to the thickness of the first quarter wave plate (106).

2. A complex amplitude light field control device, characterized in that: include: A second transmission-type modulation device (202), the upper and lower surfaces of which are respectively provided with a second quarter-wave plate (2021) and a third quarter-wave plate (2022); A reflective modulation device (201) adopts a silicon-based liquid crystal structure, wherein the left half SLM1 and the right half SLM2 correspond to the third beam splitter (203) and the fourth beam splitter (204), respectively; The second transmission-type modulation device (202) is located on the light-emitting surface of the fourth beam splitter (204), and the upper and lower surfaces thereof are respectively provided with a second 1 / 4 wave plate (2021) and a third 1 / 4 wave plate (2022); the light-emitting surface of the third beam splitter (203) corresponds to the light-incident surface of the fourth beam splitter (204); the reflection-type modulation device (201) is divided into a left half SLM1 and a right half SLM2 by the third beam splitter (203) and the fourth beam splitter (204); The third beam splitter (203) and the fourth beam splitter (204) are both polarization-independent beam splitting devices, and the reflective modulation device (201) is fixed below the third beam splitter (203) and the fourth beam splitter (204); A fourth quarter wave plate (205) and a bottom polarizer (206) are arranged between the fourth beam splitter (204) and the right half SLM2 of the reflective modulation device (201); The second dielectric layer (207) is arranged between the third beam splitter (203) and the left half SLM1 of the reflective modulation device (201), and its thickness is equal to the sum of the thicknesses of the fourth quarter wave plate (205) and the bottom polarizer (206).

3. The complex amplitude light field control device according to claim 1, characterized in that: The first transmission-type modulation device (101) is fixed on the upper surface of the first beam splitter (102).

4. The complex-amplitude light field control device according to claim 2, wherein: The reflective modulation device (201) is fixed below the third beam splitter (203) and the fourth beam splitter (204).

5. The complex amplitude light field control device according to claim 1, characterized in that: The optical path difference between the first transmission-type modulation device (101) and the reflection-type modulation device (103) is within a near-field range of <5 cm.

6. The complex amplitude light field control device according to claim 1, characterized in that: The complex amplitude light field control device is coated with an anti-reflection thin film coating on both the glass and air interfaces.

7. The complex-amplitude light field control device according to claim 1, characterized in that: The thickness of the first dielectric layer (104) is equal to the thickness of the first quarter wave plate (106).

8. The complex amplitude light field control device according to claim 2, characterized in that: The bottom polarizer (206) is arranged on the upper surface of the right half SLM2 of the reflective modulation device (201), and its polarization direction is consistent with the optical axis direction of the liquid crystal molecules in the reflective modulation device (201), and is used to maintain the compact structure of the device.

9. A method for using a complex amplitude light field control device, characterized in that: include: First design: The incident light is guided to be incident on the first transmission modulator (101) after being expanded and collimated, and the arrangement of the liquid crystal molecules is controlled by changing the voltage applied to the liquid crystal layer of the first transmission modulator (101), thereby achieving amplitude modulation of the incident light by using orthogonal polarizers on the upper and lower surfaces to generate a transmitted light field; The transmitted light field passes through the first beam splitter (102) and is then irradiated onto the left half SLM1 of the reflective modulation device (103), thereby modulating the phase of the incident light and generating a reflected light field, wherein the polarization direction of the transmitted light field remains parallel to the optical axis direction of the liquid crystal molecules in the reflective modulation device (103); The reflected light field is sequentially passed through the first beam splitter (102) and the second beam splitter (105) to reach the right half SLM2 of the reflective modulation device (103), and the light field is polarized and modulated by a first quarter wave plate (106) arranged on the surface thereof to generate a final reflected light field, wherein the fast axis direction of the first quarter wave plate (106) forms a specific angle with the optical axis direction of the liquid crystal molecules in the reflective modulation device (103); The reflected light field is transmitted through the second beam splitter (105) to achieve separate control of amplitude, phase and polarization. The first transmission modulator (101) and the reflective modulator (103) share a common drive control. According to specific application requirements, a hologram is generated using a holographic algorithm and loaded onto the first transmission and reflective modulators. According to the target light field phase distribution, the phase of the left half of the reflective modulator (103) is used to compensate for the additional phase caused by amplitude and polarization modulation. Second design: The reflective modulation device (201) is used for amplitude and phase modulation of the light field, and the second transmissive modulation device (202) is used for modulating the polarization of the light field; The incident light is guided to undergo beam expansion and collimation, and then passes through a third beam splitter (203) to be incident on the left half SLM1 of the reflective modulation device (201), where phase modulation is performed and a reflected light field is generated, wherein the polarization direction of the incident light remains parallel to the optical axis direction of the liquid crystal molecules in the reflective modulation device (201); The reflected light field is sequentially passed through the third beam splitter (203) and the fourth beam splitter (204) to reach the right half SLM2 of the reflective modulation device (201), and amplitude modulation is performed by a fourth quarter wave plate (205) and a bottom polarizer (206) arranged on the surface thereof to generate a reflected light field, wherein the fast axis direction of the fourth quarter wave plate (205) forms a specific angle with the optical axis direction of the liquid crystal molecules in the reflective modulation device (201); The reflected light field is transmitted through the fourth beam splitter (204) to the second transmission modulator (202) for polarization modulation and emission, which is achieved by arranging a second quarter wave plate (2021) and a third quarter wave plate (2022) on the upper and lower surfaces of the second transmission modulator (202), wherein the fast axis directions of the fourth quarter wave plate (205) are perpendicular to each other, and the optical axis direction of the liquid crystal molecules in the second transmission modulator (202) forms a specific angle with the fast axis direction of the fourth quarter wave plate (205), and the SLM1 phase modulation of the reflection modulator (201) is used to compensate for the amplitude of the light field and the additional phase generated by the polarization modulation.

Images