Liquid crystal pure phase control power reconfigurable large-angle hybrid multi-beam system and method

Abstract

The application discloses a liquid crystal pure phase control power reconfigurable large-angle hybrid multi-beam system, wherein the outgoing light beam of a laser passes through a polarizer, a liquid crystal optical phased array, a liquid crystal optical phase modulation wave plate, a quarter wave plate and a PBS in sequence, a part of the light beam is emitted from a substrate glass as horizontal polarized light according to the programmed deflection angle and power size; the remaining laser is reflected by the diagonal surface of the PBS to become vertical polarized light, is reflected by a total reflection device, is recovered as horizontal polarized light under the modulation of a half wave plate, is reflected by the total reflection surface of a total reflection prism module and is modulated by the liquid crystal optical phased array again, is modulated by a horizontal polarized light intensity modulator for the second time to emit the second horizontal polarized light, and is circulated in sequence until the last time of being modulated by the horizontal polarized light intensity modulator, and the multi-beam horizontal polarized light with the number, intensity and angle of the outgoing beam from the last PBS being independently configurable is emitted.

Description

Technical Field

[0001] This invention belongs to the fields of liquid crystal optical phased array, light field modulation, and free space optical communication technology, and specifically relates to a liquid crystal pure phase control power reconfigurable large-angle hybrid multi-beam system, and a method for reconfiguring large-angle hybrid multi-beams using this system. Background Technology

[0002] With the development of integrated air-space-ground communication architecture and the current advancement and demand for 6G satellite internet, inter-satellite backbone laser communication has become one of the preferred solutions for high throughput, high bandwidth, low latency, and strong anti-interference capabilities. Facing the demands of constellation satellites with variable and diverse orbits, multi-mode compatibility, and multi-orbit / different-orbit link networking, optical terminals urgently need lightweight, agile, and large-angle beam deflection capabilities. Traditional mechanical laser control systems are slow and suffer from asymmetrical rotational inertia, making it impossible to achieve multi-beam access at arbitrary angles, especially for different-orbit link access and sudden relay link access requirements. Optical phased array devices are characterized by small size, low power consumption, light weight, no rotational inertia, and easy integration, making them ideal for special platforms such as airborne, missile-borne, and spaceborne systems. Furthermore, optical phased array (OPA) technology not only enables fast, agile, and high-precision beam control but also allows for arbitrary beamforming.

[0003] Currently, small deflection angles and low diffraction efficiency are the main technical bottlenecks limiting space-to-space laser communication, space-to-ground laser communication, short-range atmospheric laser communication, and quantum communication technologies. Whether it's lidar and laser collimators, laser-guided seekers and laser directed-energy weapons, autonomous driving, laser communication networks, and new lidar systems, there is an unprecedented and urgent need for improved deflection angles and efficiency of space laser beams.

[0004] Currently, the deflection angle of a single optical phased array antenna is generally small, typically theoretically not exceeding ±10°, and a single optical antenna can only deflect one beam. Due to manufacturing process errors and limitations in materials and equipment, the actual deflection angle is even smaller. In phased array beam deflection schemes, the deflection angle range and efficiency are generally contradictory, therefore, large-angle deflection is less efficient. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a liquid crystal pure phase control power reconfigurable large-angle hybrid multi-beam system that uses a catadioptric optical path design and a matching approach wavefront control algorithm to achieve multi-beam, large deflection angle while maintaining high deflection efficiency, faster response speed, and independent control of beam power intensity. This enables tracking, aiming, high-speed communication, and adaptive adjustment of laser link communication margin for fast targets. Furthermore, a method for reconstructing large-angle hybrid multi-beam systems using this system is also provided.

[0006] The objective of this invention is achieved through the following technical solution: a liquid crystal pure phase control power reconfigurable large-angle hybrid multi-beam system, comprising a laser, a polarizer, a liquid crystal optical phased array, a liquid crystal optical phase modulation waveplate, a quarter-wave plate, a half-wave plate, a PBS combined reflector module, a glass substrate, and a total reflection prism module.

[0007] The liquid crystal optical phased array is spatially divided into multiple uniform sub-aperture working regions, each sub-aperture corresponding to one or a pair of reflecting surfaces;

[0008] The total internal reflection prism module includes a long transparent horizontal plane and multiple short inclined planes of the total internal reflection prism module. The long transparent horizontal plane is parallel to and closely attached to the upper substrate glass of the liquid crystal optical phased array. The short inclined planes serve as total internal reflection surfaces to achieve total internal reflection of the beam and are distributed in a sawtooth pattern. The polarizer is located on the upper substrate glass of the liquid crystal optical phased array and is adjacent to the left side of the total internal reflection prism module. The laser is located above the polarizer.

[0009] The PBS combined reflector module consists of PBS and total reflection device arranged in a spatially intersecting manner. Both PBS and total reflection device are glued onto a glass substrate. The reflective surface of the PBS and the total reflection surface of the total reflection device adjacent to its right side form a "V" shape structure. Furthermore, the two adjacent reflective surfaces in the PBS combined reflector module are parallel to the two adjacent total reflection surfaces of the total reflection prism module, respectively.

[0010] The liquid crystal optical phase modulation waveplate is an integrated planar waveplate composed of spatially intersecting liquid crystal working areas and non-liquid crystal working areas, which is bonded to the lower substrate glass of the liquid crystal optical phased array. The quarter-wave plate has multiple sub-apertures distributed below the liquid crystal working area of ​​the liquid crystal optical phase modulation waveplate. The half-wave plate has multiple sub-apertures distributed below the non-liquid crystal working area of ​​the liquid crystal optical phase modulation waveplate. The sub-apertures of the quarter-wave plate and the half-wave plate are spatially intersected and spliced ​​to form an integrated planar waveplate, which is bonded to the liquid crystal optical phase modulation waveplate and the PBS combined reflector module, respectively. The sub-apertures of the liquid crystal optical phase modulation waveplate, the quarter-wave plate, the half-wave plate, the total internal reflection device, and the PBS are of equal length.

[0011] The first sub-aperture of the liquid crystal optical phase modulation waveplate, the first sub-aperture of the quarter-wave plate, and the first PBS are located below the polarizer; starting from the second sub-aperture of the liquid crystal optical phase modulation waveplate, each sub-aperture corresponds to a total reflection surface of the total reflection prism module. The second sub-aperture of the liquid crystal optical phase modulation waveplate, the first sub-aperture of the half-wave plate, and the first total reflection device are located below the liquid crystal optical phased array corresponding to the first total reflection surface of the total reflection prism module.

[0012] The number of sub-apertures in both the liquid crystal optical phased array and the liquid crystal optical phase modulation waveplate is odd, with a quarter-wave plate and a PBS arranged sequentially below the last sub-aperture.

[0013] The liquid crystal optical phased array sub-aperture, liquid crystal optical phase modulation waveplate, quarter-wave plate and PBS form a horizontal polarization light intensity modulator; the last sub-aperture of the liquid crystal optical phased array, the last sub-aperture of the liquid crystal optical phase modulation waveplate, the last quarter-wave plate and the last PBS of the combined reflector module form an arbitrary reconfigurable multi-beam generator with regional beam approach amplitude-phase dual parameters jointly adjustable.

[0014] The beam emission direction of the phased array beam deflection system is as follows: the laser beam first passes through a polarizer, and its polarization direction is the target linearly polarized light required by the liquid crystal optical phased array. This linearly polarized light passes sequentially through the liquid crystal optical phased array, the liquid crystal optical phase modulation waveplate, the quarter-wave plate, and the PBS. A portion of the beam is emitted from the substrate glass according to the programmed deflection angle and power, becoming horizontally polarized light, thus controlling the first emitted laser beam. The remaining laser beam is reflected by the diagonal surface of the PBS and becomes vertically polarized light. After being reflected by the total internal reflection device, the vertically polarized light is modulated by the half-wave plate and restored to horizontally polarized light. This horizontally polarized light is then re-injected into the liquid crystal optical phased array and modulated a second time. After being reflected by the total internal reflection surface of the total internal reflection prism module, it is modulated again by the liquid crystal optical phased array and then modulated a second time by the horizontally polarized light intensity modulator, emitting the second horizontally polarized light beam. This cycle continues until the last time the beam is modulated by the horizontally polarized light intensity modulator, after which multiple horizontally polarized light beams with independently configurable number, intensity, and angle are emitted from the last PBS.

[0015] The total internal reflection device consists of two identical triangular prisms with their inclined surfaces joined together to form a cube structure. The left triangular prism is a transparent prism, and the inclined surface of the right triangular prism is a total internal reflection surface; or the left triangular prism is a transparent prism with its inclined surface being a total internal reflection surface, and the right triangular prism is a transparent or opaque prism.

[0016] Alternatively, the total internal reflection device may be a right-angled triangular prism with a single inclined plane as the total internal reflection surface;

[0017] Alternatively, the total reflection device may be a tilted planar total reflection mirror;

[0018] PBS is made of a pair of high-precision right-angle prisms bonded together, with a polarizing medium film coated on the hypotenuse of one of the prisms.

[0019] The feed electrode in the last sub-aperture of the liquid crystal optical phase modulation waveplate is a uniformly arranged phased array electrode unit array, while the feed electrodes in the other sub-apertures are single electrodes with a width equal to the side length of the PBS.

[0020] All sub-apertures in the liquid crystal optical phase modulation waveplate are filled with liquid crystal. When the liquid crystal optical phase modulation waveplate is a rectangular structure, the angle between the anchoring orientation direction of the liquid crystal alignment layer and the boundary of the waveplate is 45°. When the liquid crystal optical phase modulation waveplate is of other envelope shape, the angle between the anchoring orientation direction and the edge of the laser incident surface of the PBS is 45°.

[0021] The quarter-wave plate and the half-wave plate are both integrated in a liquid crystal device to form an integrated planar wave plate; the working liquid crystals of the aperture of the quarter-wave plate and the aperture of the half-wave plate are driven by independent feeding electrodes; the feeding electrodes in the last aperture of the quarter-wave plate are uniformly arranged phased array electrode units, which are used to independently control the beam wavefront cross section of the local area space.

[0022] In liquid crystal devices integrated with quarter-wave plates and half-wave plates, the orientation direction of the liquid crystal alignment layer is parallel to the vertically polarized light of the PBS, i.e., vertical alignment.

[0023] Another objective of this invention is to provide a liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system, which is implemented using the above-mentioned system and includes the following steps:

[0024] Step 1, System Setup and Calibration: Build a power-reconfigurable large-angle hybrid multibeam system with pure phase control of liquid crystal according to the optical path. Adjust the elevation and azimuth angles of the PBS combined reflector module and the total reflection prism module until the two ends of the two modules are aligned and in the same vertical space, and the laser incident end faces of the two modules are parallel. Move the PBS combined reflector module horizontally so that the total reflection surface of the PBS combined reflector module is parallel to the total reflection surface of the total reflection prism module. Then, adjust the laser to be incident on the first PBS, and adjust the azimuth and elevation angles of the PBS combined reflector module so that the propagation direction of the outgoing light from the last PBS of the PBS combined reflector module is parallel to the propagation direction of the incident light from the first PBS.

[0025] Align the sub-aperture regions of the integrated plane waveplates of the quarter-wave plate and half-wave plate with the corresponding PBS or total reflection device of the PBS combined mirror module, apply refractive index matching liquid, and cure with ultraviolet light; readjust the azimuth and elevation angles of the PBS combined mirror module so that the propagation direction of the emitted light from the last PBS of the PBS combined mirror module is parallel to the propagation direction of the initial emitted light from the laser.

[0026] Next, align the sub-aperture regions of the liquid crystal optical phase modulation waveplate with the corresponding sub-aperture regions of the integrated plane waveplate of the quarter-wave plate and half-wave plate, apply a refractive index matching liquid, and cure under ultraviolet light; then adjust the azimuth and elevation angles of the PBS combined mirror module, the integrated plane waveplate of the quarter-wave plate and half-wave plate, and the liquid crystal optical phase modulation waveplate assembly again, so that the propagation direction of the emitted light from the last PBS of the PBS combined mirror module is parallel to the propagation direction of the initial emitted light from the laser;

[0027] Next, a refractive index matching liquid is evenly coated on the outer side of the glass substrates on both sides of the liquid crystal optical phased array. It is placed between the PBS combined mirror module and the liquid crystal optical phase modulation waveplate. The PBS combined mirror module, the integrated planar waveplate and the liquid crystal optical phase modulation waveplate assembly are moved vertically to make the liquid crystal optical phased array fit tightly against the liquid crystal optical phase modulation waveplate. Then, it is cured by irradiation with ultraviolet light.

[0028] A polarizer is placed in close contact with the upper substrate glass of the liquid crystal optical phased array and the side of the total internal reflection prism module, and then cured by ultraviolet light.

[0029] Step 2: Set the parameters and operating wavelength of the liquid crystal optical phased array: Set the spatial period of the device array to [value missing]. The operating wavelength is ;

[0030] Step 3: Set the number of target beams, deflection angle, normalized beam intensity, number of sub-apertures, and number of sub-aperture array elements: Set the number of target beams to Q, and the beam deflection angle... and normalized intensity for:

[0031] q is 1, 2, ..., Q

[0032] The number of sub-apertures in the effective working area of ​​the quarter-wave plate (5) is The number of array elements for the last sub-aperture of the liquid crystal optical phased array (3) and the quarter-wave plate is ; This represents the total energy intensity of the incident laser, ignoring the effects of waveplate absorption and reflection. The intensity of the qth emitted laser beam;

[0033] Step 4: Calculate the liquid crystal phase modulation amount of the target angle beam corresponding to the sub-aperture and the phase modulation amount of the liquid crystal phase modulation waveplate. Based on the right-hand Cartesian coordinate system, we obtain:

[0034] (1) When the number of beams Q≤ At that time, the first The sub-aperture phase modulation amount of each liquid crystal optical phase modulation waveplate is:

[0035]

[0036] In the Near-field two-dimensional spatial coordinates of the aperture region The phase at that point is:

[0037]

[0038] in, ≤N, Represented as:

[0039]

[0040] (2) When the number of beams Q> In this case, the liquid crystal optical phase modulation waveplate will serve as the core unit for arbitrary multi-beam sub-apertures. At this time, the array element electrodes will be independently controlled, and the coordinates of the last sub-aperture of the liquid crystal optical phase modulation waveplate will be determined. Upper phase modulation amount and the coordinates of the last sub-aperture of the liquid crystal phased array The phase modulation amount on is Represented as:

[0041]

[0042] in, for The maximum value, , and They represent the first in space. , and Each beam corresponds to a near-field coordinate point The required amount of phase modulation;

[0043] Step 5: Load the phase modulation signal: According to the phase-voltage mapping table of the spatial light modulator, find the near-field coordinate points respectively. of and The corresponding voltage value is obtained, and the voltage matrix of all regions of the liquid crystal optical phase modulation waveplate and liquid crystal optical phased array is generated. Finally, they are merged into a complete voltage bit map. This voltage bit map is loaded onto the corresponding liquid crystal optical phase modulation waveplate and liquid crystal optical phased array modulator, and finally the power reconfigurable large-angle hybrid multi-beam beam deflection is realized.

[0044] The beneficial effects of this invention are:

[0045] 1. This invention discloses a liquid crystal pure phase-controlled power reconfigurable large-angle hybrid multi-beam system based on a liquid crystal optical phased spatial light modulator. It employs a sub-aperture partitioning control method and an optical path folding design to achieve continuous spatial superposition of laser near-field phases. The optical path design is simple, enabling programmable continuous beam deflection with large angles, high deflection efficiency, and fast response speed based on a single spatial light modulator. This method is applicable to large-angle beam deflection using other types of laser spatial light modulators, metasurface modulators, waveguide modulators, and microwave phased arrays.

[0046] 2. This invention is based on a liquid crystal optical phased array spatial light modulator to realize multi-beam, multi-angle and arbitrary intensity multi-parameter configurable laser output. It can realize simple small-scale, large-angle programmable arbitrary multi-beam output, as well as complex large-scale, large-angle arbitrary multi-beam output.

[0047] 3. This invention, based on liquid crystal materials and Wiener processing technology, enables a highly integrated, low-cross-section hybrid multi-beam generation system. Compared to traditional mechanical deflection schemes, it achieves ultra-low cost and high reliability, consistency, and stability.

[0048] 4. This invention supports individual devices with extremely low or insufficient phase modulation depth. In this case, the deflection angle can be continuously adjusted and the phase of the outgoing light can be adjusted. This addresses the bottleneck issue that liquid crystal materials with low refractive index differences cannot be used as phased array materials under the same thickness.

[0049] 5. The system debugging steps of this invention are simple. Based on a single device, it ensures the consistency of each sub-aperture region, greatly reducing the alignment requirements of ordinary cascaded structures and the distortion problems caused by wavefront differences. Based on a spatial light modulator, a novel phase modulation algorithm with alternating phase gradient of sub-apertures is adopted, which realizes the ability to multiply multiple parameters such as the deflection angle range, number of beams, and beam energy adjustment depth of a single liquid crystal phased array device. It can meet the needs of new-type lidar for large field of view and fast target tracking and aiming. Its large deflection angle and fast response capability provide theoretical feasibility support and technical guarantee for the realization of free space laser communication networking. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system of the present invention.

[0051] Figure 2 This is a diagram showing the sub-aperture partitioning structure and near-field distribution of the liquid crystal phased array (OPA) in this embodiment;

[0052] Figure 3 This is a schematic diagram of the PBS combined reflector module structure of the present invention;

[0053] Figure 4 This is a stacked diagram of the integrated device of the liquid crystal optical phase modulation waveplate, quarter-wave plate and half-wave plate of the present invention;

[0054] Figure 5 This is a schematic diagram of the integrated device of the quarter-wave plate and half-wave plate of the present invention;

[0055] Figure 6 This is a flowchart of the liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam method of the present invention;

[0056] Explanation of reference numerals in the attached figures:

[0057] 1: Laser; 2: Polarizer; 3: Liquid crystal optical phased array; 4: Liquid crystal optical phase modulation waveplate; 5: Quarter-wave plate; 5-1, 5-2, 5-3, 5-4: Quarter-wave plate aperture; 6: Half-wave plate; 6-1, 6-2, 6-3, 6-4: Half-wave plate aperture; 7: PBS combined reflector module; 7-1, 7-3, 7-5, 7-7, 7-9: PBS; 7-2, 7-4, 7-6, 7-8: Total internal reflection device; 8: Glass substrate; 9: Total internal reflection prism module; 9-1~9-8: Total internal reflection surface of the reflector prism module. Detailed Implementation

[0058] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0059] like Figure 1 As shown, the liquid crystal pure phase control power reconfigurable large-angle hybrid multi-beam system of the present invention has an overall sandwich laminated structure, including a laser 1, a polarizer 2, a liquid crystal optical phase array (OPA) 3, a liquid crystal optical phase modulation waveplate (OPM) 4, a quarter-wave plate (QWP) 5, a half-wave plate (HWP) 6, a PBS combined reflector module 7, a glass substrate 8, and a total reflection prism module 9.

[0060] The liquid crystal optical phased array is spatially divided into multiple uniform sub-aperture working regions 3-1 to 3-9, each sub-aperture corresponding to one or a pair of reflecting surfaces, such as... Figure 2 As shown;

[0061] The total internal reflection prism module 9 includes a long-side transparent horizontal plane 9-9 and multiple short inclined planes of the total internal reflection prism module. In this embodiment, it includes 8 short inclined planes, namely 9-1 to 9-8. The long-side transparent horizontal plane is parallel to and closely attached to the upper substrate glass of the liquid crystal optical phased array 3. The short inclined planes serve as total internal reflection surfaces to achieve total internal reflection of the light beam and are distributed in a sawtooth pattern. The polarizer 2 is located on the upper substrate glass of the liquid crystal optical phased array 3 and is adjacent to the left side 9-10 of the total internal reflection prism module 9. The laser 1 is located above the polarizer 2.

[0062] The total internal reflection prism module 9 serves to reflect light beams. Its reflective surfaces are coated with both metal and dielectric films to enhance reflectivity. In this embodiment, a 90° angle between two adjacent total internal reflection surfaces is used as an example, but it is not limited to 90°. Based on the reflection function, the prism form is not limited to a conical prism, a monolithic prism, a monolithic all-metal mirror, or a discrete component adhesive structure. The size and spatial period of adjacent total internal reflection surfaces are not limited to combinations such as equal, unequal, sparse, or discrete. Any surface that can achieve total internal reflection can be used as a total internal reflection surface.

[0063] The PBS combined reflector module 7 consists of PBSs (7-1, 7-3, 7-5, 7-7, 7-9) arranged in a spatially cross pattern and total internal reflection devices (7-2, 7-4, 7-6, 7-8), as shown below. Figure 3 As shown. Both the PBS and the total reflection device are glued onto the glass substrate 8; wherein the reflective surface of the PBS and the total reflection surface of the total reflection device adjacent to its right side form a "V" shaped structure, and the two adjacent reflective surfaces in the PBS combined reflector module 7 (the reflective surface of the PBS and the total reflection surface of the total reflection device adjacent to its right side, 7-15, 7-25) are parallel to the two adjacent total reflection surfaces (9-2, 9-1) of the total reflection prism module 9 respectively;

[0064] The liquid crystal optical phase modulation waveplate 4 is an integrated planar waveplate composed of spatially intersecting liquid crystal working areas (4-1, 4-3, 4-5, 4-7, 4-9) and non-liquid crystal working areas (air or transparent medium, etc., 4-2, 4-4, 4-6, 4-8), and is bonded to the lower substrate glass of the liquid crystal optical phase array 3; the quarter-waveplate 5 has multiple sub-apertures (5-1~5-5) distributed below the liquid crystal working areas of the liquid crystal optical phase modulation waveplate 4; the half-waveplate 6 has multiple sub-apertures (6-1~6- 4) Distributed below the non-liquid crystal working area of ​​the liquid crystal optical phase modulation waveplate 4; the sub-apertures of the quarter-wave plate 5 and the half-wave plate 6 are spatially interlocked to form an integrated planar waveplate, and are respectively bonded to the liquid crystal optical phase modulation waveplate 4 and the PBS combined reflector module 7; the sub-apertures of the liquid crystal optical phase modulation waveplate 4, the quarter-wave plate 5, the half-wave plate 6, the total internal reflection device, and the PBS are of equal length; the stacking diagram of the integrated device of the liquid crystal optical phase modulation waveplate, the quarter-wave plate, and the half-wave plate is shown in the figure. Figure 4 As shown.

[0065] The first sub-aperture of the liquid crystal optical phase modulation waveplate 4, the first sub-aperture of the quarter-wave plate, and the first PBS are located below the polarizer 2; starting from the second sub-aperture, each sub-aperture of the liquid crystal optical phase modulation waveplate 4 corresponds to a total reflection surface of the total reflection prism module 9, and the second sub-aperture of the liquid crystal optical phase modulation waveplate 4, the first sub-aperture of the half-wave plate, and the first total reflection device are located below the liquid crystal optical phase array 3 corresponding to the first total reflection surface of the total reflection prism module 9;

[0066] The number of sub-apertures of the liquid crystal optical phased array 3 and the liquid crystal optical phase modulation waveplate 4 are both odd, and below the last sub-aperture are the quarter-wave plate 5 and the PBS.

[0067] The liquid crystal optical phased array sub-aperture, liquid crystal optical phase modulation waveplate 4, quarter-wave plate 5 and PBS form a horizontal polarized light (P-light) intensity modulator; the last sub-aperture 3-9 of liquid crystal optical phased array 3, the last sub-aperture 4-9 of liquid crystal optical phase modulation waveplate, the last quarter-wave plate 5-5 and the last PBS7-9 of PBS combined reflector module form an arbitrary reconfigurable multi-beam generator with regional beam approach amplitude-phase dual parameters jointly adjustable.

[0068] The beam emission direction of the phased array beam deflection system is as follows: the emitted beam of laser 1 first passes through polarizer 2, and its polarization direction is the target linearly polarized light required by liquid crystal optical phased array 3. This linearly polarized light passes through liquid crystal optical phased array 3, liquid crystal optical phase modulation waveplate 4, quarter-wave plate 5 and PBS in sequence. A portion of the beam is emitted from substrate glass 8 according to the programmed deflection angle and power, becoming horizontally polarized light (P-beam), realizing the control of the first emitted laser beam. The remaining laser beam is reflected by the diagonal surface of PBS and becomes vertically polarized light (S-beam). After being reflected by the total internal reflection device, the vertically polarized light is restored to horizontally polarized light under the modulation of the half-wave plate. This horizontally polarized light is re-injected into liquid crystal optical phased array 3 and modulated a second time. After being reflected by the total internal reflection surface of the total internal reflection prism module, it is modulated again by liquid crystal optical phased array 3 and then modulated a second time by the horizontally polarized light intensity modulator, emitting the second horizontally polarized light beam. This cycle continues until the last time it is modulated by the horizontally polarized light intensity modulator, after which multiple horizontally polarized light beams with independently configurable number, intensity and angle are emitted from the last PBS.

[0069] The total internal reflection device consists of two identical triangular prisms with their inclined surfaces joined together to form a cube structure. The left triangular prism is a transparent prism, and the inclined surface of the right triangular prism is a total internal reflection surface; or the left triangular prism is a transparent prism with its inclined surface being a total internal reflection surface, and the right triangular prism is a transparent or opaque prism.

[0070] Alternatively, the total internal reflection device may be a right-angled triangular prism with a single inclined plane as the total internal reflection surface;

[0071] Alternatively, the total reflection device may be a tilted planar total reflection mirror, such as tilted at 45°.

[0072] The structure of the total internal reflection device is not limited to the above-described configuration. Any device that can achieve total internal reflection of light at an oblique angle can be used as the total internal reflection device of this invention.

[0073] PBS stands for Polarizing Beam Splitter. A polarizing beam splitter can split incident unpolarized light into two perpendicular linearly polarized beams. The P-polarized beam passes through completely, while the S-polarized beam is reflected at a 45-degree angle, with its outgoing direction forming a 90-degree angle with the P-beam. This invention's polarizing beam splitter is composed of a pair of high-precision right-angle prisms bonded together, with a polarizing beam splitting dielectric film coated on the hypotenuse of one of the prisms.

[0074] The feed electrode in the last sub-aperture of the liquid crystal optical phase modulation waveplate 4 is a uniformly arranged phased array electrode unit array, while the feed electrodes in the other sub-apertures are single electrodes with a width equal to the side length of the PBS.

[0075] In the liquid crystal optical phase modulation waveplate 4, all sub-apertures 4-1 to 4-9 are filled with liquid crystal. When the liquid crystal optical phase modulation waveplate 4 has a rectangular structure, the angle between the anchoring orientation direction of the liquid crystal alignment layer and the boundary of the waveplate is 45°. When the liquid crystal optical phase modulation waveplate 4 has other envelope shapes, the angle between the anchoring orientation direction and the edge of the laser incident surface of the PBS is 45°. The liquid crystal is filled entirely at once, which facilitates device fabrication. During use, the liquid crystals in 4-2, 4-4, 4-6, and 4-8 are not controlled or are given a zero voltage, allowing the liquid crystals to exist in the form of a normal homogeneous medium.

[0076] All sub-apertures 4-1 to 4-9 in the liquid crystal optical phase modulation waveplate 4 are filled with liquid crystal. When the liquid crystal optical phase modulation waveplate 4 is a rectangular structure, the angle between the anchoring orientation direction of the liquid crystal alignment layer and the boundary of the waveplate is 45°. When the liquid crystal optical phase modulation waveplate 4 is in other envelope shape, the angle between the anchoring orientation direction and the edge of the laser incident surface of the PBS is 45°.

[0077] The quarter-wave plate 5 and the half-wave plate 6 are both integrated into a single liquid crystal device, forming an integrated planar wave plate, such as... Figure 5 As shown; the working liquid crystals of the aperture of the quarter-wave plate 5 and the aperture of the half-wave plate 6 are both driven by independent feed electrodes; the feed electrodes in the last aperture of the quarter-wave plate 5 are uniformly arranged phased array electrode units, which are used to independently control the beam wavefront cross section of the local area space.

[0078] In the liquid crystal device integrated with quarter-wave plate 5 and half-wave plate 6, the orientation direction of the liquid crystal alignment layer is parallel to the vertically polarized light of PBS, i.e., vertical alignment.

[0079] The function of HWP is to provide the direction of beam deflection rotation. This scheme is not limited to passive half-wave plates, active half-wave plates, active Faraday rotators, or polarization rotation devices such as optical crystals.

[0080] The number of PBS units, total reflection devices, and reflective surfaces of the total reflection prism module in the PBS combined reflector module, as well as the number of sub-apertures of the liquid crystal optical phase modulation waveplate 4, the quarter-wave plate 5, and the half-wave plate 6, are all examples and are not limited to the number in the current example.

[0081] For two-dimensional phased deflection, the PBS combined reflector module 7 and total reflection prism module 9 are not limited to one-dimensional prisms or one-dimensional reflecting surfaces, but include various forms such as reflecting arc surfaces, trihedral pyramids and circular arc pyramids, multi-dimensional reflecting surfaces and polygonal reflecting prisms.

[0082] like Figure 6 As shown, the liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system of the present invention, implemented using the above-described system, includes the following steps:

[0083] Step 1, System Setup and Calibration: Build a liquid crystal pure phase controlled power reconfigurable large-angle hybrid multibeam system according to the optical path. Adjust the elevation and azimuth angles of the PBS combined reflector module 7 and the total internal reflection prism module 9 until the two modules are level at both ends and in the same vertical space (the two modules have the same thickness, i.e., from...). Figure 1 In the middle view, the front and back of the two modules are aligned respectively, and the laser incident end faces of the two modules are parallel; the PBS combined reflector module 7 is moved horizontally so that the total reflection surface of the PBS combined reflector module 7 is parallel to the total reflection surface of the total reflection prism module 9; then the laser is adjusted to be incident on the first PBS, and the azimuth and elevation angles of the PBS combined reflector module 7 are adjusted so that the propagation direction of the outgoing light of the last PBS of the PBS combined reflector module 7 is parallel to the propagation direction of the incident light of the first PBS;

[0084] Align the sub-aperture regions of the integrated planar waveplates of quarter-wave plate 5 and half-wave plate 6 with the corresponding PBS or total reflection device of the PBS combined reflector module, apply refractive index matching liquid, and cure under ultraviolet light; readjust the azimuth and elevation angles of the PBS combined reflector module 7 so that the propagation direction of the emitted light from the last PBS of the PBS combined reflector module 7 is parallel to the propagation direction of the initial emitted light from the laser.

[0085] Next, align the sub-aperture regions of the liquid crystal optical phase modulation waveplate 4 with the corresponding sub-aperture regions of the integrated plane waveplates of the quarter-wave plate 5 and half-wave plate 6, apply a refractive index matching liquid, and cure under ultraviolet light; then adjust the azimuth and elevation angles of the PBS combined mirror module 7, the integrated plane waveplate of the quarter-wave plate 5 and half-wave plate 6 and the liquid crystal optical phase modulation waveplate assembly again, so that the propagation direction of the emitted light from the last PBS of the PBS combined mirror module 7 is parallel to the propagation direction of the initial emitted light from the laser;

[0086] Next, a refractive index matching liquid is evenly coated on the outer side of the glass substrates on both sides of the liquid crystal optical phased array 3. It is then placed between the PBS combined mirror module 7 and the liquid crystal optical phase modulation waveplate 4. The integrated planar waveplate and liquid crystal optical phase modulation waveplate assembly, which combines the PBS combined mirror module 7, quarter-wave plate 5, and half-wave plate 6, is moved vertically so that the liquid crystal optical phased array 3 is in close contact with the liquid crystal optical phase modulation waveplate. Then, it is cured by irradiation with ultraviolet light.

[0087] Place the polarizer 2 in close contact with the upper substrate glass of the liquid crystal optical phased array 3 and the side of the total internal reflection prism module 9, and cure it with ultraviolet light.

[0088] Step 2: Set the parameters and operating wavelength of the liquid crystal optical phased array: Set the spatial period of the device array to [value missing]. The operating wavelength is ;

[0089] Step 3: Set the number of target beams, deflection angle, normalized beam intensity, number of sub-apertures, and number of sub-aperture array elements: Set the number of target beams to Q, and the beam deflection angle... and normalized intensity for:

[0090] q is 1, 2, ..., Q

[0091] The number of sub-apertures in the effective working area of ​​the quarter-wave plate (5) is The number of array elements for the last sub-aperture of the liquid crystal optical phased array (3) and the quarter-wave plate is ; This represents the total energy intensity of the incident laser, ignoring the effects of waveplate absorption and reflection. The intensity of the qth emitted laser beam;

[0092] Step 4: Calculate the liquid crystal phase modulation amount of the target angle beam corresponding to the sub-aperture and the phase modulation amount of the liquid crystal phase modulation waveplate. Based on the right-hand Cartesian coordinate system, we obtain:

[0093] (1) When the number of beams Q≤ At that time, the first The sub-aperture phase modulation amount of each liquid crystal optical phase modulation waveplate is:

[0094]

[0095] In the Near-field two-dimensional spatial coordinates of the aperture region The phase at that point is:

[0096]

[0097] in, ≤N, Represented as:

[0098]

[0099] (2) When the number of beams Q> In this case, the liquid crystal optical phase modulation waveplate will serve as the core unit for arbitrary multi-beam sub-apertures. At this time, the array element electrodes will be independently controlled, and the coordinates of the last sub-aperture of the liquid crystal optical phase modulation waveplate will be determined. Upper phase modulation amount and the coordinates of the last sub-aperture of the liquid crystal phased array The phase modulation amount on is Represented as:

[0100]

[0101] in, for The maximum value, , and They represent the first in space. , and Each beam corresponds to a near-field coordinate point The required amount of phase modulation;

[0102] Step 5: Load the phase modulation signal: According to the phase-voltage mapping table of the spatial light modulator, find the near-field coordinate points respectively. of and The corresponding voltage value is obtained, and the voltage matrix of all regions of the liquid crystal optical phase modulation waveplate 4 and the liquid crystal optical phased array 3 is generated. Finally, they are merged into a complete voltage bit map. This voltage bit map is loaded onto the corresponding liquid crystal optical phase modulation waveplate and liquid crystal optical phased array modulator, and finally the power reconfigurable large-angle hybrid multi-beam beam deflection is realized.

[0103] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A liquid crystal pure phase-controlled power reconfigurable large-angle hybrid multibeam system, characterized in that, It includes a laser (1), a polarizer (2), a liquid crystal optical phased array (3), a liquid crystal optical phase modulation waveplate (4), a quarter-wave plate (5), a half-wave plate (6), a PBS combined reflector module (7), a glass substrate (8), and a total reflection prism module (9). The liquid crystal optical phased array (3) is spatially divided into multiple uniform sub-aperture working areas, each sub-aperture corresponding to one or a pair of reflective surfaces; The total internal reflection prism module (9) includes a long transparent horizontal plane and multiple short inclined planes of the total internal reflection prism module. The long transparent horizontal plane is parallel to and closely attached to the upper substrate glass of the liquid crystal optical phased array (3). The short inclined planes serve as total internal reflection surfaces to achieve total internal reflection of the beam and are distributed in a sawtooth pattern. The polarizer (2) is located on the upper substrate glass of the liquid crystal optical phased array (3) and is adjacent to the left side of the total internal reflection prism module (9). The laser (1) is located above the polarizer (2). The PBS combined reflector module (7) consists of PBS and total reflection device arranged in a spatial cross arrangement. Both PBS and total reflection device are glued to the glass substrate (8). The reflective surface of the PBS and the total reflection surface of the total reflection device adjacent to its right side form a "V" shaped structure. The two adjacent reflective surfaces in the PBS combined reflector module (7) are parallel to the two adjacent total reflection surfaces of the total reflection prism module (9). The liquid crystal optical phase modulation waveplate (4) is composed of a liquid crystal working area and a non-liquid crystal working area arranged in a spatial cross pattern, forming an integrated planar waveplate, and is bonded to the lower substrate glass of the liquid crystal optical phase array (3); the quarter-wave plate (5) has multiple sub-apertures, distributed below the liquid crystal working area of ​​the liquid crystal optical phase modulation waveplate (4); the half-wave plate (6) has multiple sub-apertures, distributed below the non-liquid crystal working area of ​​the liquid crystal optical phase modulation waveplate (4); the sub-apertures of the quarter-wave plate (5) and the half-wave plate (6) are spatially cross-joined to form an integrated planar waveplate, and are bonded to the liquid crystal optical phase modulation waveplate (4) and the PBS combined reflector module (7) respectively; the sub-apertures of the liquid crystal optical phase modulation waveplate (4), the quarter-wave plate (5), the half-wave plate (6), the total internal reflection device, and the PBS are of equal length; The first sub-aperture of the liquid crystal optical phase modulation waveplate (4), the first sub-aperture of the quarter-wave plate, and the first PBS are located below the polarizer (2); starting from the second sub-aperture, each sub-aperture of the liquid crystal optical phase modulation waveplate (4) corresponds to a total reflection surface of the total reflection prism module (9), and the second sub-aperture of the liquid crystal optical phase modulation waveplate (4), the first sub-aperture of the half-wave plate, and the first total reflection device are located below the liquid crystal optical phase array (3) corresponding to the first total reflection surface of the total reflection prism module (9); The number of sub-apertures of the liquid crystal optical phased array (3) and the liquid crystal optical phase modulation waveplate (4) are both odd, and below the last sub-aperture are a quarter-wave plate (5) and a PBS.

2. The liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system according to claim 1, characterized in that, The liquid crystal optical phased array aperture, liquid crystal optical phase modulation waveplate (4), quarter-wave plate (5) and PBS constitute a horizontal polarization light intensity modulator; The last sub-aperture of the liquid crystal optical phased array (3), the last sub-aperture of the liquid crystal optical phase modulation waveplate, the last quarter-wave plate, and the last PBS of the PBS combined reflector module form an arbitrary reconfigurable multi-beam generator with regional beam approach amplitude-phase dual parameters jointly adjustable.

3. The liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system according to claim 2, characterized in that, The beam emission direction of the system is as follows: the output beam of the laser (1) first passes through the polarizer (2), and its polarization direction is the target linearly polarized light required by the liquid crystal optical phased array (3). This linearly polarized light passes through the liquid crystal optical phased array (3), the liquid crystal optical phase modulation waveplate (4), the quarter-wave plate (5), and the PBS in sequence. A portion of the beam is emitted from the glass substrate (8) according to the deflection angle and power magnitude designed in the program, and becomes horizontally polarized light, realizing the control of the first output laser beam; the remaining laser becomes vertically polarized light after being reflected by the diagonal surface of the PBS; vertical polarization After being reflected by the total internal reflection device, the light is restored to horizontally polarized light under the modulation of the half-wave plate. The horizontally polarized light is then injected into the liquid crystal optical phased array (3) and modulated a second time. After being reflected by the total internal reflection surface of the total internal reflection prism module, it is modulated again by the liquid crystal optical phased array (3) and then modulated a second time by the horizontally polarized light intensity modulator, and a second beam of horizontally polarized light is emitted. This process is repeated until the last time the light is modulated by the horizontally polarized light intensity modulator, and then multiple beams of horizontally polarized light are emitted from the last PBS, the number of beams, intensity, and angle of which can be independently configured.

4. The liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system according to claim 1, characterized in that, The total internal reflection device consists of two identical triangular prisms with their inclined surfaces joined together to form a cube structure. The left triangular prism is a transparent prism, and the inclined surface of the right triangular prism is a total internal reflection surface; or the left triangular prism is a transparent prism with its inclined surface being a total internal reflection surface, and the right triangular prism is a transparent or opaque prism. Alternatively, the total internal reflection device may be a right-angled triangular prism with a single inclined plane as the total internal reflection surface; Alternatively, the total reflection device may be a tilted planar total reflection mirror; PBS is made of a pair of high-precision right-angle prisms bonded together, with a polarizing medium film coated on the hypotenuse of one of the prisms.

5. The liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system according to claim 1, characterized in that, The feed electrode in the last sub-aperture of the liquid crystal optical phase modulation waveplate (4) is a uniformly arranged phased array electrode unit array, while the feed electrodes in the other sub-apertures are single electrodes with a width equal to the side length of the PBS.

6. The liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system according to claim 1, characterized in that, All sub-apertures in the liquid crystal optical phase modulation waveplate (4) are filled with liquid crystal. When the liquid crystal optical phase modulation waveplate (4) is a rectangular structure, the angle between the anchoring orientation direction of the liquid crystal alignment layer and the boundary of the waveplate is 45°. When the liquid crystal optical phase modulation waveplate (4) is in other envelope shape, the angle between the anchoring orientation direction and the edge of the laser incident surface of the PBS is 45°.

7. The liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system according to claim 1, characterized in that, The quarter-wave plate (5) and the half-wave plate (6) are both integrated in a liquid crystal device to form an integrated planar wave plate. The working liquid crystals of the aperture of the quarter-wave plate (5) and the aperture of the half-wave plate (6) are driven by independent feeding electrodes. The feeding electrode in the last aperture of the quarter-wave plate (5) is a uniformly arranged phased array electrode unit array, which is used to independently control the beam wavefront section of the local area space.

8. The liquid crystal pure phase control power reconfigurable large-angle hybrid multibeam system according to claim 7, characterized in that, In a liquid crystal device integrating a quarter-wave plate (5) and a half-wave plate (6), the orientation direction of the liquid crystal alignment layer is parallel to the vertically polarized light of the PBS, i.e., vertical alignment.

9. A liquid crystal pure phase-controlled power reconfigurable large-angle hybrid multibeam system, implemented using the system described in any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1, System Setup and Calibration: Build a liquid crystal pure phase controlled power reconfigurable large-angle hybrid multi-beam system according to the optical path. Adjust the pitch and azimuth angles of the PBS combined reflector module (7) and the total reflection prism module (9) until the two modules are level at both ends and in the same vertical space, and the laser incident end faces of the two modules are parallel. Move the PBS combined reflector module (7) horizontally so that the total reflection surface of the PBS combined reflector module (7) is parallel to the total reflection surface of the total reflection prism module (9). Then adjust the laser to be incident on the first PBS, and adjust the azimuth and pitch angles of the PBS combined reflector module (7) so that the propagation direction of the outgoing light from the last PBS of the PBS combined reflector module (7) is parallel to the propagation direction of the incident light from the first PBS. Align the sub-aperture regions of the integrated planar wave plate (5) and half-wave plate (6) with the corresponding PBS or total reflection device of the PBS combined reflector module, apply refractive index matching liquid, and cure with ultraviolet light; readjust the azimuth and elevation angles of the PBS combined reflector module (7) so that the propagation direction of the emitted light from the last PBS of the PBS combined reflector module (7) is parallel to the propagation direction of the initial emitted light from the laser. Next, align the sub-aperture regions of the liquid crystal optical phase modulation waveplate (4) with the corresponding sub-aperture regions of the integrated plane waveplates of the quarter-wave plate (5) and half-wave plate (6), apply a refractive index matching liquid, and cure under ultraviolet light; then adjust the azimuth and elevation angles of the integrated plane waveplate and liquid crystal optical phase modulation waveplate assembly of the PBS combined reflector module (7), the quarter-wave plate (5), and the half-wave plate (6) so that the propagation direction of the emitted light from the last PBS of the PBS combined reflector module (7) is parallel to the propagation direction of the initial emitted light from the laser. Next, the refractive index matching liquid is evenly coated on the outer side of the glass substrate on both sides of the liquid crystal optical phased array (3), and placed between the PBS combined mirror module (7) and the liquid crystal optical phase modulation waveplate (4). The integrated planar waveplate and liquid crystal optical phase modulation waveplate assembly of the PBS combined mirror module (7), quarter waveplate (5) and half waveplate (6) are moved vertically so that the liquid crystal optical phased array (3) is in close contact with the liquid crystal optical phase modulation waveplate. Then, it is cured by irradiation with ultraviolet light. Place the polarizer (2) in close contact with the upper substrate glass of the liquid crystal optical phased array (3) and the side of the total internal reflection prism module (9), and cure it with ultraviolet light. Step 2: Set the parameters and operating wavelength of the liquid crystal optical phased array: Set the spatial period of the device array to [value missing]. The operating wavelength is ; Step 3: Set the number of target beams, deflection angle, normalized beam intensity, number of sub-apertures, and number of sub-aperture array elements: Set the number of target beams to Q, and the beam deflection angle... and normalized intensity for: q is 1, 2, ..., Q; The number of sub-apertures in the effective working area of ​​the quarter-wave plate (5) is The number of array elements for the last sub-aperture of the liquid crystal optical phased array (3) and the quarter-wave plate is ; This represents the total energy intensity of the incident laser, ignoring the effects of waveplate absorption and reflection. The intensity of the qth emitted laser beam; Step 4: Calculate the liquid crystal phase modulation amount of the target angle beam corresponding to the sub-aperture and the phase modulation amount of the liquid crystal phase modulation waveplate. Based on the right-hand Cartesian coordinate system, we obtain: (1) When the number of beams Q≤ At that time, the first The sub-aperture phase modulation amount of each liquid crystal optical phase modulation waveplate is: ； In the Near-field two-dimensional spatial coordinates of the aperture region The phase at that point is: ； in, ≤N, Represented as: ； (2) When the number of beams Q> In this case, the liquid crystal optical phase modulation waveplate will serve as the core unit for arbitrary multi-beam sub-apertures. At this time, the array element electrodes will be independently controlled, and the coordinates of the last sub-aperture of the liquid crystal optical phase modulation waveplate will be determined. Upper phase modulation amount and the coordinates of the last sub-aperture of the liquid crystal phased array The phase modulation amount on is Represented as: ； in, for The maximum value, , and They represent the first in space. , and Each beam corresponds to a near-field coordinate point The required amount of phase modulation; Step 5: Load the phase modulation signal: According to the phase-voltage mapping table of the spatial light modulator, find the near-field coordinate points respectively. of and The corresponding voltage value is obtained, and the voltage matrix of all regions of the liquid crystal optical phase modulation waveplate (4) and liquid crystal optical phased array (3) is generated. Finally, they are merged into a complete voltage bit map. This voltage bit map is loaded onto the corresponding liquid crystal optical phase modulation waveplate and liquid crystal optical phased array modulator, and finally the power reconfigurable large angle hybrid multi-beam beam deflection is realized.

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