A parameter-controllable random structured light generating device and method

Abstract

The application discloses a parameter-controllable random structure light generating device and method, a laser emits a light beam which sequentially passes through a linear polarizer and a beam expander and then is incident to a beam splitter, the light beam reflected by the beam splitter is a first light beam, the first light beam enters a digital micromirror device loaded with a holographic film to be modulated, a second light beam is obtained after the modulation, the second light beam is incident to the beam splitter again, and is incident to a common-path interference system after being transmitted; the second light beam passes through a first lens in the common-path interference system, positive and negative first-order light spots are filtered out through a pinhole diaphragm at a focal plane of the first lens, the positive and negative first-order light spots pass through two half-wave plates respectively, and then pass through a second lens and a Ronchi grating to be combined into a random vector light beam. The application can accurately generate a random structure light beam, and compared with a traditional structure light beam, can simultaneously control the polarization degree and the spatial coherence degree of the generated random structure light beam.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to a device and method for generating random structured light with controllable parameters. Background Technology

[0002] The statements in this section are merely background information relating to this disclosure and do not necessarily constitute prior art.

[0003] Structured beams have attracted widespread attention in recent years, with broad applications in information detection, optical imaging, and optical capture. For example, typical structured beams include vortex beams, which carry helical phases. These phases, with different topological charges, form infinite dimensions in Hilbert space, providing a powerful carrier for high-data-rate communications. Typical structured beams also include vector beams, which exhibit non-uniform spatial distributions in complex fields and polarizations. By modulating polarization, tightly focused vector beams can generate exotic polarization topologies, leading to new optical applications. To date, various schemes for generating vector beams have been proposed. Although the manipulation of structured beams is becoming increasingly sophisticated, the development of new degrees of freedom in structured beams remains a pressing pursuit in the field of optical technology, as new degrees of freedom in structured beams have a profound impact on new applications.

[0004] Existing research on generating structured beams can only produce a very limited number of random structured beams. It is impossible to precisely control the spatial coherence and polarization state of structured light, making it difficult to generate physically realizable random structured light with all controllable parameters. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a parameter-controllable random structured light generation device and method, which can accurately generate random structured light beams. Compared with traditional structured light beams, this invention can simultaneously control the polarization degree and spatial coherence of the generated random structured light beam, providing new opportunities for arbitrarily manipulating the polarization state of the structured light beam inside the Poincaré sphere, and has important applications in free-space optical communication and optical imaging.

[0006] In a first aspect, this disclosure provides a parameter-controllable random structured light generation device, including a laser, a linear polarizer, a beam expander, a digital micromirror device loaded with a hologram, a beam splitter, and a common-path interference system; the laser emits a beam that passes sequentially through the linear polarizer and the beam expander and then enters the beam splitter, the beam reflected by the beam splitter is the first beam, the first beam enters the digital micromirror device loaded with the hologram for modulation, after modulation to obtain the second beam, the second beam then enters the beam splitter, and after transmission, enters the common-path interference system;

[0007] The common-path interference system includes a first lens and a second lens constituting an optical 4F system, a pinhole aperture and two half-wave plates and a Ronchi grating arranged sequentially on the focal planes of the two lenses; the second beam passes through the first lens, and at the focal plane of the first lens, it is filtered out into positive and negative first-order light spots by the pinhole aperture. The positive and negative first-order light spots pass through the two half-wave plates respectively, and then pass through the second lens and the Ronchi grating to combine into a random vector beam.

[0008] Further technical solutions also include random structured light measurement devices;

[0009] The device includes a third and fourth lens constituting an optical 4F system, a beam splitter, a linear polarizer, a quarter-wave plate, and a charge-coupled device.

[0010] The random vector beam obtained by the Ronchi grating passes through the third and fourth lenses that constitute the optical 4F system, and then enters the beam splitter at the rear focal plane of the fourth lens. The beam transmitted by the beam splitter is the third beam, and the beam reflected by the beam splitter is the fourth beam.

[0011] The third beam passes through a linear polarizer and a quarter-wave plate in sequence and is incident into the charge-coupled device. The Stokes parameters of the beam are obtained by calculation based on the recorded beam data.

[0012] The fourth beam is then transmitted and reflected by a beam splitter to the corresponding charge-coupled devices (CCDs), and the mutual coherence function of the beams is measured according to the Hanbury-Brown-Twiss principle.

[0013] Secondly, this disclosure provides a parameter-controllable random structured light generation method, implemented using the aforementioned parameter-controllable random structured light generation device, comprising the following steps:

[0014] The laser beam passes through a linear polarizer and a beam expander in sequence and then enters a beam splitter. The beam reflected by the beam splitter is the first beam. The first beam enters a digital micromirror device loaded with a hologram for modulation. After modulation, a second beam is obtained. The second beam then enters the beam splitter and, after transmission, enters a common-path interference system.

[0015] The second beam passes through the first lens, and at the focal plane of the first lens, it is filtered by a pinhole aperture to produce positive and negative first-order light spots. After passing through two half-wave plates, the positive and negative first-order light spots are combined with the second lens and the Ronchi grating to form a random vector beam.

[0016] Further technical solutions also include:

[0017] The random vector beam obtained by the Ronchi grating passes through the third and fourth lenses that constitute the optical 4F system, and then enters the beam splitter at the rear focal plane of the fourth lens. The beam transmitted by the beam splitter is the third beam, and the beam reflected by the beam splitter is the fourth beam.

[0018] The third beam passes through a linear polarizer and a quarter-wave plate in sequence and is incident into the charge-coupled device. The Stokes parameters of the beam are obtained by calculation based on the recorded beam data.

[0019] The fourth beam is then transmitted and reflected by a beam splitter to the corresponding charge-coupled devices, and the mutual coherence function of the beam is measured according to the Hanbury Brown-Twiss principle.

[0020] The above one or more technical solutions have the following beneficial effects:

[0021] 1. This invention provides a parameter-controllable random structured light generation device and method, which can accurately generate random structured light beams. Compared with traditional structured light beams, this invention can simultaneously control the polarization degree and spatial coherence of the generated random structured light beams, providing new opportunities for arbitrarily manipulating the polarization state of the structured light beam inside the Poincaré sphere, and has important applications in free-space optical communication and optical imaging.

[0022] 2. The present invention can generate random structured light beams in real time through a random structured light generation device with controllable parameters. Moreover, the device and method provide new opportunities for arbitrarily manipulating the polarization state of the structured light beam inside the Poincaré sphere, and have important applications in free-space optical communication and optical imaging. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 This is a schematic diagram of the generating apparatus described in Embodiment 1 of the present invention;

[0025] Figure 2 This is a schematic diagram of the electromagnetic Gaussian Sher mode beam in the source plane and the light source plane in an embodiment of the present invention, and a schematic diagram of the beam in the light source plane after passing through linear polarizers at different angles (45° and 135°).

[0026] Figure 3 This is a polarization trajectory diagram comparing the theoretical and experimental results of the electromagnetic Gaussian Sherman mode beam obtained in this embodiment of the invention.

[0027] Figure 4This is a diagram showing the light intensity distribution of a random cylindrical vector beam at different propagation distances after being focused by a lens in an embodiment of the present invention, and the corresponding polarization results compared with the theoretical and experimental results.

[0028] Figure 5 The intensity distribution and Stokes parameters of the two additional cylindrical vector beams generated on the focal plane.

[0029] Among them, 1. Helium-neon laser, 2. First linear polarizer, 3. Beam expander, 4. First beam splitter, 5. Digital micromirror device, 6. First lens, 7. Pinhole aperture, 8. Half-wave plate, 9. Second lens, 10. Ronchi grating, 11. Mirror, 12. Third lens, 13. Fourth lens, 14. Second beam splitter, 15. Third beam splitter, 16. Second linear polarizer, 17. Quarter-wave plate, 18. First charge-coupled device, 19. Second charge-coupled device, 20. Third charge-coupled device. Detailed Implementation

[0030] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] Example 1

[0033] This embodiment provides a parameter-controllable random structured light generation device, such as... Figure 1 As shown, the system includes a laser, a linear polarizer, a beam expander, a digital micromirror device (DMD) with a hologram loaded, a beam splitter (BS), and a common-path interference system. The beam emitted by the helium-neon laser 1 passes sequentially through the first linear polarizer 2 and the beam expander 3 before being incident on the first beam splitter 4. The beam reflected by the first beam splitter 4 is the first beam. The first beam enters the digital micromirror device (DMD) with the hologram loaded for modulation, and after modulation, a second beam is obtained. The second beam then enters the first beam splitter 4, and after transmission, it enters the common-path interference system.

[0034] In the above-described device, a beam emitted by a helium-neon laser enters a digital micromirror device (DMD) for modulation. Considering that the DMD can only receive vertically polarized beams, a linear polarizer is added after the helium-neon laser in this embodiment. The beam with the desired polarization direction is selected by the linear polarizer, and a beam expander is set after the linear polarizer to expand the beam so that the beam waist width can be precisely controlled subsequently.

[0035] The aforementioned digital micromirror device (DMD) loads a hologram containing information about the beam model to be generated (beam amplitude and phase). This hologram, containing complex Gaussian random numbers, is loaded onto the DMD and is referred to as a complex screen. By loading the hologram, the DMD is divided into two screens, each controlling the electric field in two directions independently—that is, controlling the two complex screens separately. Each complex screen contains the beam polarization and spatial coherence. The two complex screens modulate the first beam, controlling the amplitude and phase of the beam on both screens to ensure that the amplitude and phase of the modulated beam match the beam model information in the hologram, thereby generating parameter-controllable random structured light.

[0036] The common-path interference system includes two lenses constituting an optical 4F system, a pinhole aperture 7 and a half-wave plate 8 located on the focal plane of the two lenses and arranged sequentially, and a Ronche grating 10; the second beam passes through the first lens 6, and at the focal plane of the first lens 6, it is filtered out into positive and negative first-order light spots by the pinhole aperture 7. The positive and negative first-order light spots pass through the two half-wave plates 8 respectively, and then pass through the second lens 9 and the Ronche grating 10 to combine into a random vector beam.

[0037] The lenses and pinhole apertures mentioned above are used to filter out the positive and negative first-order light spots required for the experiment. Without these settings, they cannot be directly filtered out. The half-wave plates are used to modulate the polarization of the two beams. After passing through the two half-wave plates, the positive and negative first-order light spots become left-handed circularly polarized beams and right-handed circularly polarized beams, respectively. Then, through the Ronchi grating, the two beams with different polarization states are combined to obtain the final random vector beam.

[0038] Furthermore, in order to verify the effectiveness of the above-mentioned generating device in generating random structured light, this embodiment also provides a random structured light measurement device, which includes two lenses constituting an optical 4F system, a beam splitter, a linear polarizer, a quarter-wave plate, and a charge-coupled device (CCD). The random vector beam obtained through the Ronchi grating 10 passes through the reflector 11 and is then incident on the random structured light measurement device. After passing through two lenses (i.e., the third lens 12 and the fourth lens 13) constituting the optical 4F system, it is incident on the second beam splitter 14 at the rear focal plane of the fourth lens 13. The beam transmitted by the second beam splitter 14 is the third beam, and the beam reflected by the second beam splitter 14 is the fourth beam. The third beam passes sequentially through the second linear polarizer 16 and the quarter-wave plate 17 and is incident on the first charge-coupled device 18. The beam Stokes parameters are obtained by calculating the beam recorded by the first charge-coupled device CCD 18. The fourth beam is then transmitted and reflected by the third beam splitter 15 to the corresponding charge-coupled devices CCD (i.e., the second charge-coupled device 19 and the second charge-coupled device 20). The mutual coherence function of the beam is measured according to the Hanbury Brown-Twiss principle.

[0039] The above describes the process of splitting the generated random vector beam into two beams using a beam splitter, and then measuring the Stokes parameters and cross-correlation function of each beam separately. Since the measurement methods for the Stokes parameters and cross-correlation function differ, this embodiment employs different devices for the third and fourth beams. For the third beam, measuring the Stokes parameters requires calculating the light intensity and phase delay difference after passing through a linear polarizer; therefore, a linear polarizer and a half-wave plate are used here. For the fourth beam, measuring the cross-coherence function requires separate measurements; therefore, another beam splitter is used to separate the fourth beam, and measurements are performed separately using a charge-coupled device (CCD).

[0040] The Stokes parameters and cross-correlation function of the generated random structured light are measured using the aforementioned random structured light measurement device, further verifying the effectiveness of the device in generating random structured light.

[0041] Example 2

[0042] This embodiment proposes a parameter-controllable random structured light generation method, which is implemented using the generation device proposed in Embodiment 1 above. The specific steps include:

[0043] Step S1: The laser beam passes through the first linear polarizer 2 and the beam expander 3 in sequence and then enters the first beam splitter 4. The beam reflected by the first beam splitter 4 is the first beam. The first beam enters the digital micromirror device DMD5 loaded with holograms for modulation. After modulation, the second beam is obtained. The second beam then enters the first beam splitter 4 and, after transmission, enters the common interference system.

[0044] Step S2: The second beam passes through the first lens 6, and at the focal plane of the first lens 6, it is filtered by the pinhole aperture 7 to produce positive and negative first-order light spots. The positive and negative first-order light spots pass through two half-wave plates 8 respectively, and then pass through the second lens 9 and the Ronchi grating 10 to form a random vector beam.

[0045] The specific process of step S2 above is as follows: the light reflected by the digital micromirror device (DMD) is scattered into multiple diffraction orders, and the two electric field components required to generate random structured light are generated by the first diffraction order. Therefore, the diffracted light enters the optical 4F system composed of two lenses again through the beam splitter BS. A double-aperture filter (i.e., the aforementioned pinhole aperture) is placed at the focal plane of the first lens to filter out the required first-order diffraction order. The light passes through two half-wave plates to rotate the polarization state of the light by 90 degrees, with the other one used as compensation. Finally, the light is combined into a random vector beam through a Ronchi grating. The beam obtained by recombination is the required random structured vector beam.

[0046] Furthermore, to verify the effectiveness of the generated random structured light, this embodiment also provides a method for measuring random structured light, including:

[0047] Step S3: After the random vector beam passes through the third lens 12 and the fourth lens 13 constituting the optical 4F system, it is incident on the second beam splitter 14 at the rear focal plane of the fourth lens 13. The beam transmitted by the second beam splitter 14 is the third beam, and the beam reflected by the second beam splitter 14 is the fourth beam. The third beam passes through the second linear polarizer 16 and the quarter-wave plate 17 in sequence and is incident on the first charge-coupled device 18. The beam Stokes parameters of the beam are obtained by calculating the beam recorded by the first charge-coupled device CCD 18.

[0048] In step S4, the fourth beam is transmitted and reflected by the third beam splitter 15 to the corresponding charge-coupled devices (CCDs) (i.e., the second charge-coupled device 19 and the second charge-coupled device 20), and the mutual coherence function of the beam is measured according to the Hanbury Brown-Twiss principle.

[0049] The effectiveness of the proposed solution in this embodiment is further illustrated by taking the following examples of generating an electromagnetic Gaussian Sher mode beam and generating a random cylindrical vector beam.

[0050] (I) Specific methods for theoretically synthesizing Shermodar correlated random vector fields

[0051] First, we will introduce and analyze the electromagnetic Gaussian Sher mode beam from a theoretical perspective.

[0052] The correlation function of a random structured light field is represented by a 2×2 matrix, namely:

[0053]

[0054] Where r1 and r2 are two points in two-dimensional space, μ is the correlation function, and x and y are the horizontal and vertical directions in two-dimensional space.

[0055] in:

[0056]

[0057]

[0058] In the above formula, f is a vector in the spatial frequency domain, T is the complex screen, * denotes conjugate, and Φ αα Let T be the power spectral density function. α It is a sample function extracted from a zero-mean complex Gaussian random process, therefore:

[0059]

[0060] That is, Φ αα This is the Fourier transform of the correlation matrix shown in formula (1). T α Expanding into a Fourier series, we get:

[0061]

[0062] Where J is the zero-mean circular complex Gaussian Fourier series coefficient, m and n are the discrete spatial frequency exponents, and L... x and L y These are the physical sizes of the discrete meshes in the x and y directions, respectively. Taking the autocorrelation of equation (5) and comparing it with equation (3), we obtain the following relationship:

[0063]

[0064] Among them, <|J α [m,n]| 2 The variance is equal to the variance of the Fourier series coefficients. Since it is a circular complex Gaussian, the variances of the real and imaginary parts are equal.

[0065] Combining the above analysis results, the two complex screens T x and T y It can be represented as a product r α The inverse Fourier transform is given by the following equation:

[0066]

[0067] Where, r α N is a circular complex Gaussian random number with zero mean and unit variance. x ×N y The matrix, where u and v are discrete space indices.

[0068] According to formula (7), T x and T y The interrelationships are as follows:

[0069]

[0070] Therefore, in order to generate the cross-correlation function u xy Random numbers can be represented in the following form:

[0071]

[0072] According to equation (8) and the experimental setup for generating random structured light described above, a hologram is generated and loaded onto the DMD, dividing the DMD into two complex screens, which are then used to generate T independently and simultaneously. x (u1,v1) and T y Modulation is performed using (u2,v2). Based on the above theoretical analysis, a specific modulation scheme for how the complex screen modulates the beam is obtained. Based on equation (7), the Monte Carlo method is used to synthesize T. α That is, based on clearly defined and set random numbers, the Monte Carlo method is used to synthesize complex screen T. x and T y This generates the corresponding hologram.

[0073] (II) Implementing Random Field Theory Methods on DMD Screens

[0074] A DMD is an amplitude-limited spatial light modulator that modulates the amplitude of a light beam. A hologram is generated and then adjusted and loaded onto the DMD. To fully modulate the amplitude and phase of the complex field, the complex field, including the x and y field components implemented by the random field, is written in the following form:

[0075]

[0076] To reconstruct the complex field S(x,y) from a generated hologram that only displays amplitude, the amplitude mode takes the following form:

[0077] h(x,y)=C0a(x,y){1+cos[2πf x x-ψ(x,y)]}, (11)

[0078] Where C0 is a constant, f x ψ(x,y) is the spatial frequency in the x-direction, a(x,y) is the amplitude, and ψ(x,y) is the phase.

[0079] Equation (11) can be used to obtain the electric field vectors modulated in two directions by the hologram in the DMD.

[0080] (III) Theoretical methods for measuring the modulus of coherence

[0081] Based on optical coherence theory, the normalized autocorrelation and cross-correlation intensities of a random vector field are expressed as:

[0082]

[0083] in,

[0084] Considering that the stochastic process follows Gaussian statistics, we obtain:

[0085]

[0086] Furthermore, the normalized self-correlation and cross-correlation strengths can be simplified as follows:

[0087] |μ αβ (r1,r2)| 2 =g αβ (2) (r1,r2)-1,(α,β=x,y). (15)

[0088] In the above formula, E α (r,t) represents the electric field in the x or y direction.

[0089] According to formula (15), the square modulus of the correlation function can be measured based on the intensity correlation measurement value, that is, the result obtained by measuring the coherence function is... The final result is |μ αβ (r1,r2)| 2 .

[0090] (iv) Theoretical method for measuring beam Stokes parameters

[0091] The four Stokes parameters of the random vector field can be determined by the beam coherent polarization matrix, i.e.:

[0092]

[0093] In the above formula, J(r,r) is the cross spectral density function matrix.

[0094] In this embodiment, the Stokes parameters are measured using standard methods with the aid of polarization and a quarter-wave plate. The output intensity distribution as the beam passes through the polarizer and phase retarder is as follows:

[0095] I(θ,δ)=J xx cos 2 θ+J yy sin 2 θ+J xy e iδ sinθcosθ+J xy e -iδ cosθsinθ (17)

[0096] Where θ is the angle formed by the transmission angle between the polarizer and the x-axis; δ is the phase difference between the x and y field components introduced by the phase retarder.

[0097] Furthermore, the cross-correlation coefficient B xy The real and imaginary parts can be obtained through the Stokes parameters:

[0098]

[0099] The degree of polarization is calculated using the following formula:

[0100]

[0101] The Stokes parameters of the beam can be measured using the above formula. In other words, the Stokes parameters are measured by measuring the light intensity I(θ,δ) after passing through the polarizer.

[0102] (V) Generating an electromagnetic Gaussian Sherman mode beam

[0103] The beam model of the electromagnetic Gaussian Sherman mode source on the light source surface is as follows:

[0104]

[0105] Among them, A α A β For amplitude, σ α δ is the beam waist width. xx δ xy , and δ yy It is the spatial coherence width. It is the complex coherence coefficient.

[0106] Using the apparatus described in Example 1 and the method described in this example, an electromagnetic Gaussian Sherman mode beam is generated by modulating, generating, and loading a hologram onto a DMD using steps (I) and (II) above. This beam is then used to verify the effectiveness and flexibility of the method described in this example. The mode square experimental results of the coherence of the electromagnetic Gaussian Sherman mode source are obtained using the aforementioned measuring device, as shown in the figure. Figure 2 and Figure 3 As shown, Figure 2A schematic diagram of the light intensity of an electromagnetic Gaussian Sherman mode beam at the source plane and the light source plane is given. Figure 3 The upper part of the light intensity diagram shows the fitting curves between the experimental and theoretical results. These curves demonstrate that the beam generated in this embodiment perfectly matches the theoretical results. Meanwhile, Figure 2 and Figure 3 It also provides different angles, namely 45° (I x-y ) and 135°(I y-x A schematic diagram and fitting curve of the light intensity distribution of the beam on the light source surface after the linear polarizer is applied.

[0107] (vi) Generating random cylindrical vector beams

[0108] Based on the same method described above, a random cylindrical vector beam is generated. By generating two types of beams as examples, the flexibility of the scheme described in this embodiment is illustrated.

[0109] The polarization state of the cylindrical vector beam is mapped onto a higher-order Poincaré sphere through a certain relationship, namely:

[0110]

[0111] Where θ and φ are the polar angle and azimuth angle in spherical coordinates, LG 0,l It is the modulus of a Laguerre Gaussian topological charge of l with a radial exponent of 0. and It is the unit vector for left-handed and right-handed circular polarization.

[0112] Using a higher-order Poincaré sphere to represent the polarization state of the generated beam is simply mapping the polarization state of the generated beam onto a higher-order Poincaré sphere for intuitive understanding.

[0113] To synthesize the corresponding SCVB, the electric field is first converted into horizontal and vertical field components in a Cartesian coordinate system. Then, a 2×2 power spectrum matrix is ​​obtained through calculation. The autocorrelation function and cross-correlation function are Fourier transforms of the diagonal and anti-diagonal elements of the matrix. Based on the calculation results, the input beam is modulated, and the amplitude, phase, polarization, and coherence parameters of the beam are adjusted. The desired random structure beam is generated through the controllability of these parameters (amplitude, phase, polarization, and coherence).

[0114] In other words, in the above scheme, the corresponding parameters of the random structured light to be generated are first set, and then a hologram is generated according to the parameters. The hologram is loaded into the DMD to modulate the amplitude and phase of the input beam. After the beam is modulated, it is passed through a common-path interference system to generate the required random structured light.

[0115] This embodiment presents two beam models (electromagnetic Gaussian Sher mode beam and random cylindrical vector beam). By adjusting the parameters of each model, the feasibility of the generation scheme is verified through a beam verification method. This feasibility is specifically reflected in the generation results of these two beams.

[0116] Furthermore, such as Figure 4 As shown, the beam gradually evolves into a hollow state during transmission, and the degree of polarization further increases, while the polarization state remains unchanged. Therefore, the polarization state can also be changed by adjusting other parameters, as shown in the following example. Figure 5 As shown.

[0117] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0118] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0119] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A parameter-controllable random structured light generation device, characterized in that, The system includes a laser, a linear polarizer, a beam expander, a digital micromirror device with a hologram loaded, a beam splitter, and a common-path interference system. The laser beam passes sequentially through the linear polarizer and the beam expander before entering the beam splitter. The beam reflected by the beam splitter is the first beam. The first beam enters the digital micromirror device with the hologram loaded for modulation, and after modulation, a second beam is obtained. The second beam then enters the beam splitter, and after transmission, it enters the common-path interference system. The common-path interference system includes a first lens and a second lens constituting an optical 4F system, a pinhole aperture and two half-wave plates and a Ronche grating arranged sequentially at the focal planes of the two lenses; the second beam passes through the first lens, and at the focal plane of the first lens, it is filtered out into positive and negative first-order light spots by the pinhole aperture. The positive and negative first-order light spots pass through the two half-wave plates respectively, and then pass through the second lens and the Ronche grating to combine into a random vector beam. The hologram loaded in the digital micromirror device is called a composite screen. The hologram contains information about the beam model to be generated, including the amplitude and phase of the beam. By loading a hologram, the digital micromirror in the digital micromirror device is divided into two composite screens. The electric fields in two directions are controlled separately by the two composite screens. The composite screens contain the polarization and spatial coherence of the beam to be generated. The first beam is modulated by the two composite screens in the digital micromirror device, and the amplitude and phase of the beam on the two composite screens are controlled. The modulation process includes: Two screens and Represented as a product The inverse Fourier transform is given by the following equation: in, It contains circular complex Gaussian random numbers with zero mean and unit variance. The matrix, u , v Φα is the discrete space index, m and n are the discrete space frequency indices, Lx and Ly are the physical sizes of the discrete grids in the x and y directions, respectively, and Φαα is the power spectral density function. but and The interrelationships are as follows: To generate cross-correlation function Random numbers are represented in the following form: ； Based on the definition and setting of random numbers, the Monte Carlo method is used to synthesize complex screens. and This generates the corresponding hologram.

2. The parameter-controllable random structured light generation device as described in claim 1, characterized in that, It also includes a random structured light measurement device; The device includes a third and fourth lens constituting an optical 4F system, a beam splitter, a linear polarizer, a quarter-wave plate, and a charge-coupled device. The random vector beam obtained by the Ronchi grating passes through the third and fourth lenses that constitute the optical 4F system, and then enters the beam splitter at the rear focal plane of the fourth lens. The beam transmitted by the beam splitter is the third beam, and the beam reflected by the beam splitter is the fourth beam. The third beam passes through a linear polarizer and a quarter-wave plate in sequence and is incident into the charge-coupled device. The Stokes parameters of the beam are obtained by calculation based on the recorded beam data. The fourth beam is then transmitted and reflected by a beam splitter to the corresponding charge-coupled devices, and the mutual coherence function of the beam is measured according to the Hanbury-Brown-Twiss principle.

3. A method for generating random structured light with controllable parameters, implemented using the random structured light generation device with controllable parameters as described in any one of claims 1-2, characterized in that, Includes the following steps: The laser beam passes through a linear polarizer and a beam expander in sequence and then enters a beam splitter. The beam reflected by the beam splitter is the first beam. The first beam enters a digital micromirror device loaded with a hologram for modulation. After modulation, a second beam is obtained. The second beam then enters the beam splitter and, after transmission, enters a common-path interference system. The second beam passes through the first lens, and at the focal plane of the first lens, it is filtered by a pinhole aperture to produce positive and negative first-order light spots. After passing through two half-wave plates, the positive and negative first-order light spots are combined with the second lens and the Ronchi grating to form a random vector beam.

4. The parameter-controllable random structured light generation method as described in claim 3, characterized in that, The hologram loaded in the digital micromirror device is called the composite screen. The hologram contains information about the beam model to be generated, including the amplitude and phase of the beam.

5. The parameter-controllable random structured light generation method as described in claim 4, characterized in that, By loading a hologram, the digital micromirror device is divided into two complex screens. The electric fields in two directions are controlled separately by the two complex screens. The complex screens contain the polarization and spatial coherence of the beam to be generated. The first beam is modulated by the two complex screens in the digital micromirror device, and the amplitude and phase of the beam on the two complex screens are controlled.

6. The method for generating random structured light with controllable parameters as described in claim 5, characterized in that, The modulation process includes: Two screens and Represented as a product The inverse Fourier transform is given by the following equation: in, It contains circular complex Gaussian random numbers with zero mean and unit variance. The matrix, u , v Φα is the discrete space index; m and n are the discrete space frequency indices, Lx and Ly are the physical sizes of the discrete grids in the x and y directions, respectively, and Φαα is the power spectral density function. but and The interrelationships are as follows: To generate cross-correlation function Random numbers are represented in the following form: ； Based on the definition and setting of random numbers, the Monte Carlo method is used to synthesize complex screens. and This generates the corresponding hologram.

7. The method for generating random structured light with controllable parameters as described in claim 3, characterized in that, it further... include: The random vector beam obtained by the Ronchi grating passes through the third and fourth lenses that constitute the optical 4F system, and then enters the beam splitter at the rear focal plane of the fourth lens. The beam transmitted by the beam splitter is the third beam, and the beam reflected by the beam splitter is the fourth beam. The third beam passes through a linear polarizer and a quarter-wave plate in sequence and is incident into the charge-coupled device. The Stokes parameters of the beam are obtained by calculation based on the recorded beam data. The fourth beam is then transmitted and reflected by a beam splitter to the corresponding charge-coupled devices, and the mutual coherence function of the beam is measured according to the Hanbury-Brown-Twiss principle.

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