Ultrafast random speckle generation system, device and method

Abstract

The invention is suitable for the technical field of optics, and provides an ultrafast random speckle generation system, device and method. The ultrafast random speckle generation system comprises a mode-locked pulse laser module which generates a high-repetition-frequency femtosecond-scale broadband laser pulse optical signal; the DFT module broadens the broadband laser pulse optical signal of the femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one corresponding linear relation; the wavelength adjusting module enables the frequency domain wavelength of the broadband laser pulse optical signal to have an interference phenomenon; the speckle generation module enables broadband laser pulse optical signals with different wave crest wavelengths to generate mode interference in a two-dimensional space; and the speckle detection and calibration module performs data detection, and performs data acquisition according to wavelength information at the wave crest and random speckle distribution to complete image data processing. According to the invention, the number and speed of random speckle generation are adjusted, and the problem that the spatial modulation of single-pixel imaging is too slow is solved.

Description

Technical Field

[0001] The present invention belongs to the field of optical technology, and in particular relates to an ultrafast random speckle generation system, device and method. Background Art

[0002] Random speckle has received high attention and research in the fields of ultrafast optical information processing, ultrafast optical detection and single-pixel imaging, and is widely used in the generation of various random signals and the imaging and detection of ultrafast phenomena.

[0003] However, the development of random speckle generation devices has been slow, and the generation rate of random speckle has seriously affected its wide range of applications. Current random speckle generation devices mainly use spatial light modulators or digital micro-mirrors, and their rates are generally KHz, but due to the inherent problems of their liquid crystal or mechanical structure, it is difficult to increase the rate. There are also some reports that use the method of etching speckles onto transparent disks and rotating the disks at high speeds to generate speckles at a higher rate, but the inherent problems of their mechanical structures limit the generation rate of their speckles, and ultrafast speckle generation on the nanosecond scale cannot be achieved. Therefore, there is a need for an ultrafast speckle generation device that does not require liquid crystal or mechanical structure.

[0004] Therefore, how to adopt a new structural design to realize an ultrafast speckle generation device without the need for an active mechanical structure and increase the speckle generation rate to the nanosecond scale is a technical problem that needs to be solved at present. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide an ultrafast random speckle generation system, aiming to solve the problem of low speckle generation rate.

[0006] The embodiment of the present invention is implemented as follows: an ultrafast random speckle generation system, wherein the ultrafast random speckle generation system is provided with the following modules in sequence:

[0007] Mode-locked pulse laser module, used to generate high-repetition-rate femtosecond-scale broadband laser pulse optical signals;

[0008] DFT module, used to broaden the broadband laser pulse optical signal of femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one linear relationship;

[0009] A wavelength adjustment module, used to cause interference in the frequency domain wavelength of a broadband laser pulse optical signal;

[0010] A speckle generation module, used to make broadband laser pulse light signals with wavelengths at different peaks generate mode interference in a two-dimensional space;

[0011] The speckle detection and calibration module is used to detect the data of the speckle space image after the wavelength generation mode interference at different peaks, collect data according to the wavelength information at the peak and the random speckle distribution, and complete the image data processing.

[0012] Furthermore, the high-repetition-rate femtosecond-scale broadband laser pulse light signal generated by the mode-locked pulse laser module includes a broadband laser pulse light signal L0 (A0, λ) in the near-infrared band, where A0 is the amplitude value of the mode-locked broadband laser pulse light signal and λ is the frequency domain wavelength.

[0013] Furthermore, the DFT module is composed of a dispersion-compensating optical fiber, a long-distance ordinary single-mode optical fiber or a chirped fiber grating, the broadband laser pulse optical signal input to the DFT module is L0(A0, λ), and the broadband laser pulse optical signal output by the DFT module is L1(A1, λ(t)), λ(t)=α*t+β, wherein α and β are constants, A1 is the amplitude value of the mode-locked broadband laser pulse optical signal after broadening, and t is the pulse time domain signal.

[0014] Furthermore, the wavelength adjustment module adopts the Michelson interference structure of spatial light. When the broadband laser pulse light signal passes through the Michelson interference structure, L1(A1, λ(t)) is divided into signal light L 11 (A 11 ,λ(t)) and reference light L 12 (A 12 ,λ(t)),A 11 is the amplitude of the signal light, A 12 is the amplitude value of the reference light; after the broadened broadband laser pulse light signal passes through the Michelson interference structure, the light signal at this time becomes Among them, A2 is the amplitude value of the mode-locked broadband laser pulse light signal after passing through the Michelson interference structure, and φ is the signal light L 11 (A 11 ,λ(t)) and reference light L 12 (A 12 ,λ(t)), where λ2 is the wavelength of the light signal. After passing through the Michelson interference structure, the light signal L2(A2,λ2(t)) at this time has peak and trough values.

[0015] Furthermore, the speckle generation module uses a multimode optical fiber to obtain the distribution L3(A3, λ(z, t)) of random speckles of optical signals of wavelengths at different peaks at different times, where z is the distribution of random speckles, z=f(λ), f is a function related to z and λ, that is, the distribution z of random speckles is related to the wavelength at the peak.

[0016] Furthermore, the speckle detection and calibration module also receives a synchronization signal from the mode-locked pulse laser module.

[0017] Another object of an embodiment of the present invention is to provide an ultrafast random speckle generating device, wherein the ultrafast random speckle generating device is provided with the following modules in sequence:

[0018] Mode-locked pulse laser module, used to generate high-repetition-rate femtosecond-scale broadband laser pulse optical signals;

[0019] DFT module, used to broaden the broadband laser pulse optical signal of femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one linear relationship;

[0020] A wavelength adjustment module, used to cause interference in the frequency domain wavelength of a broadband laser pulse optical signal;

[0021] A speckle generation module, used to make broadband laser pulse light signals with wavelengths at different peaks generate mode interference in a two-dimensional space;

[0022] The speckle detection and calibration module is used to detect the data of the speckle space image after the wavelength generation mode interference at different peaks, collect data according to the wavelength information at the peak and the random speckle distribution, and complete the image data processing.

[0023] Another object of an embodiment of the present invention is to provide an ultrafast random speckle generation method, the ultrafast random speckle generation method comprising the following steps:

[0024] A mode-locked pulse laser module is used to generate a high-repetition-rate femtosecond-scale broadband laser pulse optical signal;

[0025] The DFT module is used to broaden the broadband laser pulse optical signal at the femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one linear relationship.

[0026] The wavelength adjustment module is used to make the frequency domain wavelength of the broadband laser pulse optical signal interfere;

[0027] The speckle generation module is used to make broadband laser pulse optical signals with wavelengths at different peaks generate mode interference in two-dimensional space;

[0028] The speckle detection and calibration module is used to detect the speckle spatial image after the interference of the wavelength generation pattern at different peaks, and data is collected according to the wavelength information at the peak and the random speckle distribution to complete the image data processing.

[0029] An ultrafast random speckle generation system provided by an embodiment of the present invention can not only generate ultrafast random speckles, but also adjust the number and speed of random speckle generation by adjusting the optical path difference of an interference structure; it creatively solves the problem of slow spatial modulation of traditional single-pixel imaging and can perform ultrafast modulation in space. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of an ultrafast random speckle generating device in a first embodiment;

[0031] Figure 2 The frequency domain (a) and time domain (b) result diagrams of the optical signal after entering the DFT module in the first embodiment; the frequency domain (c) and time domain (d) result diagrams of the optical signal after entering the wavelength adjustment module;

[0032] Figure 3 A schematic diagram of random speckle generated after an optical signal enters a multimode optical fiber in the first embodiment;

[0033] Figure 4 is an application environment diagram of an ultrafast random speckle generation method in the third embodiment;

[0034] Figure 5 FIG. 4 is a flow chart of the ultrafast random speckle generation method in the fourth embodiment. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] In the first embodiment, if Figure 1 As shown, an ultrafast random speckle generation system is proposed. The ultrafast random speckle generation system is configured with the following modules in sequence:

[0037] Mode-locked pulse laser module, used to generate high-repetition-rate femtosecond-scale broadband laser pulse optical signals;

[0038] DFT module, used to broaden the broadband laser pulse optical signal of femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one linear relationship;

[0039] A wavelength adjustment module, used to cause interference in the frequency domain wavelength of a broadband laser pulse optical signal;

[0040] A speckle generation module, used to make broadband laser pulse light signals with wavelengths at different peaks generate mode interference in a two-dimensional space;

[0041] The speckle detection and calibration module is used to detect the data of the speckle space image after the wavelength generation mode interference at different peaks, collect data according to the wavelength information at the peak and the random speckle distribution, and complete the image data processing.

[0042] In this embodiment, the high-repetition-rate femtosecond-scale broadband laser pulse light signal generated by the mode-locked pulse laser module includes a broadband laser pulse light signal L0 (A0, λ) in the near-infrared band, where A0 is the amplitude value of the mode-locked broadband laser pulse light signal and λ is the wavelength in the frequency domain. The femtosecond-scale broadband laser pulse repetition frequency used in this embodiment is 50 MHz, the pulse width is 44 fs, the infrared center wavelength is 1558 nm, and the bandwidth is about 20 nm.

[0043] The DFT module is composed of dispersion-compensating fiber, long-distance ordinary single-mode fiber or chirped fiber grating. After the femtosecond-scale broadband laser pulse optical signal L0 (A0, λ) with a repetition rate of 50MHz passes through the DFT module (dispersion Fourier transform module) composed of dispersion-compensating fiber, the femtosecond-scale broadband laser pulse will be broadened due to the material dispersion of the dispersion-compensating fiber, and the broadband laser pulse optical signal is broadened in the time domain, while realizing the linear correspondence between the pulse time domain signal and the frequency domain wavelength. The material dispersion value of the dispersion-compensating fiber used in this embodiment is 500ps / nm, so the femtosecond-scale pulse signal is broadened by about 500ps / nm*20nm=10ns. The broadband laser pulse optical signal input to the DFT module is L0(A0, λ), and the broadband laser pulse optical signal output by the DFT module is L1(A1, λ(t)), λ(t) = α*t+β, where α and β are constants, A1 is the amplitude value of the mode-locked broadband laser pulse optical signal after broadening, and t is the pulse time domain signal, that is, the pulse time domain signal t has a linear correspondence with the frequency domain wavelength λ. The frequency domain and time domain results of the optical signal after entering the DFT module are shown in the figure below: Figure 2 As shown in (a) and (b) in the figure, the frequency domain and time domain diagrams of the optical signal are shown.

[0044] The wavelength adjustment module can adopt the Michelson interference structure of optical fiber, spatial light or Mach-Zehnder interference structure. Take the Michelson interference structure of spatial light as an example. The broadened broadband laser pulse light signal enters the wavelength adjustment module, which adopts the Michelson interference structure of optical fiber spatial light. After passing through the interference structure, the frequency domain wavelength of the broadened broadband laser pulse will show interference phenomenon, that is, peaks and troughs will appear at different wavelengths. When the broadband laser pulse passes through the Michelson interference structure, L1(A1, λ(t)) is divided into signal light L 11 (A 11 ,λ(t)) and reference light L 12 (A 12 ,λ(t)), both of which can be abbreviated as L11 and L 12 , A 11 is the amplitude of the signal light, A 12 is the amplitude value of the reference light. After the broadened broadband laser pulse light signal passes through the Michelson interference structure, the light signal at this time becomes Among them, A2 is the amplitude value of the mode-locked broadband laser pulse light signal after passing through the Michelson interference structure, and φ is the signal light L 11 (A 11 ,λ(t)) and reference light L 12 (A 12 ,λ(t)), where λ2 is the wavelength of the optical signal. By adding an adjustable optical delay device to the reference optical path, the phase difference between the signal light and the reference light can be adjusted. After passing through the Michelson interference structure, the optical signal L2(A2,λ2(t)) at this time has a series of peaks and valleys. The frequency domain and time domain results of the optical signal after entering the wavelength adjustment module are shown in the figure below. Figure 2 As shown in (c) and (d) in the figure, the frequency domain and time domain diagrams of the optical signal are shown at this time. By comparing the corresponding positions of the peaks and troughs in the frequency domain (c) and time domain (d) diagrams of the optical signal, the relationship between the pulse time domain signal t and the frequency domain wavelength λ can be obtained. In this embodiment, by calculating Figure 2 The corresponding positions of the peaks and troughs in the frequency domain (c) and time domain (d) of the optical signal in the figure, if λ(t) = α*t+β, we can get α = 0.498, β = -2.26, λ(nm) = 0.498*t(ns)-2.26, that is, the pulse time domain signal t and the frequency domain wavelength λ have a linear correspondence. In addition, by using an adjustable optical delay device, the phase difference between the signal light and the reference light can be adjusted, that is, the distance between adjacent peaks can be adjusted, which is Δλ in the frequency domain and Δt in the time domain, as shown in Figure 2 As shown by the bidirectional arrows in the frequency domain (c) and time domain (d) diagrams, by adjusting the phase difference between the signal light and the reference light, the frequency domain or time domain interval for subsequently generating speckles can be adjusted.

[0045] The broadband laser pulse light signal after broadening after the interference structure enters the speckle generation module, which uses a multimode optical fiber with a core of 400 microns and a length of 5 meters, which can achieve mode interference in two-dimensional space at the crest of the broadened broadband laser pulse light signal. The multimode optical fiber used ensures that laser signals of different wavelengths have different random speckle distributions. Since the distribution of random speckle is related to the wavelength at the crest of the optical signal, and the wavelength of the optical signal is related to time after the optical signals of different wavelengths pass through the dispersion compensation optical fiber or the long-distance ordinary single-mode optical fiber, the distribution of random speckle of the optical signal at different wavelengths at different times can be obtained L3 (A3, λ (z, t)), where A3 is the amplitude value of the locked broadband laser pulse light signal after the speckle generation module, z is the distribution of random speckle, z = f (λ), f is a function related to z and λ, that is, the distribution of random speckle z is related to the wavelength λ at the crest. It is also known that the pulse time domain signal t and the frequency domain wavelength λ have a linear corresponding relationship. In this embodiment, λ(nm)=0.498*t(ns)-2.26, so the distribution z of the random speckle is related to the pulse time domain signal t. Figure 3 The schematic diagram shows the random speckle generated after the optical signal enters the multimode optical fiber. The laser pulse optical signal is a single-mode signal when it enters the multimode optical fiber, and the laser pulse optical signal output from the multimode optical fiber has the characteristics of random speckle distribution. According to the one-to-one correspondence between the wavelength λ and the time series t and the random speckle distribution z, it can be known that the laser pulse optical signal output from the multimode optical fiber has different random speckle distribution z at different time points t.

[0046] The generated random speckle enters the speckle detection and calibration module, which is used to detect the random speckle spatial image after the wavelength generation mode interference at different peaks, and complete the image data processing after data collection based on the wavelength information at the peak and the random speckle distribution, that is, the relationship analysis between the wavelength λ at the peak and the random speckle distribution z. The random speckle distribution z is as follows:

[0047]

[0048] Among them, x, y are the coordinates of the speckle; a m and φ n are the m- and n-order modes of amplitude and phase, respectively.

[0049] The random speckle distribution z can be calculated using the zero-mean normalized cross-correlation algorithm R ref It is used for analysis and calibration, and stores the random speckle distribution z of different wavelengths for subsequent calibration, calculation and processing. Zero-mean normalized cross-correlation algorithm R ref as follows:

[0050]

[0051] Z0 is the pixel distribution intensity of the detection image, Z ref is the pixel distribution intensity of the reference image; is the average value of the pixel distribution intensity of all detection images, is the average value of the pixel distribution intensity of all reference images.

[0052] In this embodiment, a mode-locked pulse laser module, a DFT module, a wavelength adjustment interference, a speckle generation module, and a speckle detection and calibration module are provided, which can not only realize the generation of ultrafast random speckles, but also realize the regulation of the number and speed of random speckle generation by adjusting the optical path difference of the interference structure; the problem of slow spatial modulation of traditional single-pixel imaging is creatively solved, and ultrafast modulation can be performed in space.

[0053] In a second embodiment, an ultrafast random speckle generating device is provided, and the ultrafast random speckle generating device comprises:

[0054] Mode-locked pulse laser module, used to generate high-repetition-rate femtosecond-scale broadband laser pulse optical signals;

[0055] DFT module, used to broaden the broadband laser pulse optical signal of femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one linear relationship;

[0056] A wavelength adjustment module, used to cause interference in the frequency domain wavelength of a broadband laser pulse optical signal;

[0057] A speckle generation module, used to make broadband laser pulse light signals with wavelengths at different peaks generate mode interference in a two-dimensional space;

[0058] The speckle detection and calibration module is used to detect the data of the speckle space image after the wavelength generation mode interference at different peaks, collect data according to the wavelength information at the peak and the random speckle distribution, and complete the image data processing.

[0059] In this embodiment, the ultrafast random speckle generating device is a specific structural device, and its working principle and technical effect are the same as those of the ultrafast random speckle generating system of the first embodiment, which will not be described in detail here.

[0060] In a third embodiment, if Figure 4 As shown, an application environment diagram of an ultrafast random speckle generation method is proposed. The application environment includes a computer device and the ultrafast random speckle generation system described in the first embodiment, and the computer device controls the mode-locked pulse laser module, the DFT module, the wavelength adjustment interference, the speckle generation module, and the speckle detection and calibration module.

[0061] In the fourth embodiment, Figure 5As shown, an ultrafast random speckle generation method is proposed, which is applied to the computer device in the third embodiment. The ultrafast random speckle generation method includes the following steps S102 to S110:

[0062] Step S102, using a mode-locked pulse laser module to generate a high-repetition-rate femtosecond-scale broadband laser pulse optical signal;

[0063] Step S104, using a DFT module to broaden the broadband laser pulse light signal at a femtosecond scale, so that a linear relationship between the time domain signal and the frequency domain wavelength of the broadband laser pulse light signal appears in a one-to-one correspondence;

[0064] Step S106, using a wavelength adjustment module to cause interference in the frequency domain wavelength of the broadband laser pulse light signal;

[0065] Step S108, using a speckle generation module to cause broadband laser pulse light signals with wavelengths at different peaks to generate mode interference in a two-dimensional space;

[0066] Step S110, using a speckle detection and calibration module to perform data detection on the speckle spatial image after the wavelength generation mode interference at different peaks, and perform data collection according to the wavelength information at the peak and the random speckle distribution to complete the image data processing.

[0067] In this embodiment, the specific technical means and technical effects of the ultrafast random speckle generation method have been clearly explained in the first embodiment and will not be repeated here.

[0068] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An ultrafast random speckle generation system, characterized in that: The ultrafast random speckle generation system is configured with the following modules in sequence: Mode-locked pulse laser module, used to generate high-repetition-rate femtosecond-scale broadband laser pulse optical signals; DFT module, used to broaden the broadband laser pulse optical signal of femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one linear relationship; A wavelength adjustment module, used to cause interference in the frequency domain wavelength of a broadband laser pulse optical signal; A speckle generation module, used to make broadband laser pulse light signals with wavelengths at different peaks generate mode interference in a two-dimensional space; The speckle detection and calibration module is used to detect the data of the speckle space image after the wavelength generation mode interference at different peaks, collect data according to the wavelength information at the peak and the random speckle distribution, and complete the image data processing.

2. The ultrafast random speckle generation system according to claim 1, characterized in that: The high-repetition-rate femtosecond-scale broadband laser pulse light signal generated by the mode-locked pulse laser module includes a broadband laser pulse light signal L0 (A0, λ) in the near-infrared band, where A0 is the amplitude value of the mode-locked broadband laser pulse light signal and λ is the frequency domain wavelength.

3. The ultrafast random speckle generation system according to claim 2, characterized in that: The DFT module is composed of a dispersion-compensating optical fiber, a long-distance ordinary single-mode optical fiber or a chirped fiber grating. The broadband laser pulse optical signal input to the DFT module is L0(A0, λ), and the broadband laser pulse optical signal output by the DFT module is L1(A1, λ(t)), λ(t)=α*t+β, wherein α and β are constants, A1 is the amplitude value of the mode-locked broadband laser pulse optical signal after broadening, and t is the pulse time domain signal.

4. The ultrafast random speckle generation system according to claim 3, characterized in that: The wavelength adjustment module adopts the Michelson interference structure of spatial light. When the broadband laser pulse light signal passes through the Michelson interference structure, L1(A1, λ(t)) is divided into signal light L 11 (A 11 ,λ(t)) and reference light L 12 (A 12 ,λ(t)),A 11 is the amplitude of the signal light, A 12 is the amplitude value of the reference light; after the broadened broadband laser pulse light signal passes through the Michelson interference structure, the light signal at this time becomes Among them, A2 is the amplitude value of the mode-locked broadband laser pulse light signal after passing through the Michelson interference structure, and φ is the signal light L 11 (A 11 ,λ(t)) and reference light L 12 (A 12 ,λ(t)), where λ2 is the wavelength of the light signal. After passing through the Michelson interference structure, the light signal L2(A2,λ2(t)) at this time has peak and trough values.

5. The ultrafast random speckle generation system according to claim 4, characterized in that: The speckle generation module adopts a multimode optical fiber to obtain the distribution L3(A3, λ(z, t)) of random speckles of optical signals of wavelengths at different peaks at different times, where A3 is the amplitude value of the mode-locked broadband laser pulse optical signal passing through the speckle generation module, z is the distribution of random speckles, z=f(λ), f is a function related to z and λ, that is, the distribution z of random speckles is related to the wavelength at the peak.

6. The ultrafast random speckle generation system according to any one of claims 1 to 5, characterized in that: The speckle detection and calibration module also receives a synchronization signal from the mode-locked pulse laser module.

7. An ultrafast random speckle generation device, characterized in that: The ultrafast random speckle generation device is provided with the following modules in sequence: Mode-locked pulse laser module, used to generate high-repetition-rate femtosecond-scale broadband laser pulse optical signals; DFT module, used to broaden the broadband laser pulse optical signal of femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one linear relationship; A wavelength adjustment module, used to cause interference in the frequency domain wavelength of a broadband laser pulse optical signal; A speckle generation module, used to make broadband laser pulse light signals with wavelengths at different peaks generate mode interference in a two-dimensional space; The speckle detection and calibration module is used to detect the data of the speckle space image after the wavelength generation mode interference at different peaks, collect data according to the wavelength information at the peak and the random speckle distribution, and complete the image data processing.

8. An ultrafast random speckle generation method, characterized in that: The ultrafast random speckle generation method comprises the following steps: A mode-locked pulse laser module is used to generate a high-repetition-rate femtosecond-scale broadband laser pulse optical signal; The DFT module is used to broaden the broadband laser pulse optical signal at the femtosecond scale, so that the time domain signal and the frequency domain wavelength of the broadband laser pulse optical signal have a one-to-one linear relationship. The wavelength adjustment module is used to make the frequency domain wavelength of the broadband laser pulse optical signal interfere; The speckle generation module is used to make broadband laser pulse optical signals with wavelengths at different peaks generate mode interference in two-dimensional space; The speckle detection and calibration module is used to detect the speckle spatial image after the interference of the wavelength generation pattern at different peaks, and data is collected according to the wavelength information at the peak and the random speckle distribution to complete the image data processing.

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