Optical pulse control system and control method based on ferroelectric liquid crystal

Abstract

The invention discloses an optical pulse control system and control method based on ferroelectric liquid crystal. The control system comprises an optical pulse shaping device and a control device, the light pulse shaping device comprises a clipping unit, a plurality of laser amplifiers, a polaroid and a resonant cavity. Wherein the clipping unit comprises a polarization module, a ferroelectric crystal, a polarization detection module and a high-voltage module; according to the invention, the required high voltage can be quickly reached through the ferroelectric crystal by using relatively low driving voltage; the clipping unit can achieve high-precision adjustment, and narrow pulse width output is achieved by applying the pulse width of the voltage stage to the ferroelectric crystal; the optical pulse shaping device can realize high-precision control on the phase and amplitude of the optical pulse by accurately controlling parameters of an external electric field, and provides support for complex pulse shaping; according to the invention, through combination of deep learning and real-time feedback, intelligent and dynamic accurate control of the light pulse is realized, and the method is especially suitable for complex application scenes requiring accurate control of pulse characteristics and rapid response.

Description

Technical Field

[0001] The invention relates to the field of light pulses, and in particular to a light pulse control system and a control method based on ferroelectric liquid crystal. Background Art

[0002] As the application of lasers becomes more and more extensive, the research on the controllability of the time domain waveform of optical pulses has attracted more and more attention. For example, in the great changes of laser inertial confinement, the requirements for the time filling factor of the terminal pulse are getting higher and higher, which directly leads to higher and higher requirements for the shaping of the front-end time optical pulse.

[0003] At present, the main technology used is pulse interception using electro-optical crystals such as Pockels cell and KDP (potassium dihydrogen phosphate). However, electro-optical crystals such as Pockels cell and KDP not only require a relatively high driving voltage, but also require high-precision voltage control, complex electronic driving circuits and a stable high-voltage power supply, which makes the control complexity of the overall system relatively high. Secondly, these electro-optical crystals require a high driving voltage, which results in high power consumption and easy thermal effects. These thermal effects not only affect the stability and life of the device, but may also affect the overall performance of the system. Therefore, there is an urgent need for an optical pulse control system with low driving voltage, relatively simple control circuit, easy integration and high-precision control.

[0004] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0005] The purpose of the present invention is to achieve high-precision and high-stability light pulse control through low driving voltage and simple control circuit.

[0006] The present invention provides a light pulse control system based on ferroelectric liquid crystal, characterized in that it includes a light pulse shaping device;

[0007] The optical pulse shaping device comprises a clipping unit, a plurality of laser amplifiers, a polarizer and a resonant cavity; wherein,

[0008] The clipping unit comprises: a polarizing module, a ferroelectric crystal, a polarizing module and a high-voltage module.

[0009] Preferably, in an embodiment of the present invention, the ferroelectric crystals are two or more ferroelectric liquid crystals.

[0010] Preferably, in an embodiment of the present invention, the polarizing module and the analyzing module both include a plurality of analyzers.

[0011] Preferably, in an embodiment of the present invention, it includes: a data acquisition module for acquiring beam shape images and laser pulse data in real time, a data preprocessing module, a deep learning module and a control signal generation module.

[0012] Preferably, in the embodiment of the present invention, it also includes:

[0013] The feedback optimization module is used to collect the characteristic data of the light beam and the pulse in real time and feed the data back to the deep learning module.

[0014] Preferably, in an embodiment of the present invention, the data acquisition module includes:

[0015] A camera for capturing an image of the beam's spatial distribution and a photodetector for measuring the pulse energy and pulse width.

[0016] Preferably, in an embodiment of the present invention, the control signal generating module includes: a digital signal processor and a high-speed digital-to-analog converter.

[0017] In another aspect of the present invention, a light pulse control method based on ferroelectric liquid crystal is also provided, which is used in the light pulse control system based on ferroelectric liquid crystal as described above, comprising the steps of:

[0018] S11, presetting the electric field parameters of the ferroelectric crystal in the clipping unit; and energizing the ferroelectric crystal through a voltage module according to the electric field parameters;

[0019] S12, acquiring historical data including beam spatial distribution parameters, pulse energy parameters and pulse width parameters through a data acquisition module;

[0020] S13, preprocessing the historical data to obtain modeling data of a deep learning module;

[0021] S14, constructing a light pulse prediction model based on a convolutional neural network according to the modeling data;

[0022] S15. Generate a control instruction according to the output result of the optical pulse prediction model.

[0023] Preferably, in an embodiment of the present invention, it further includes: optimizing the pulse prediction model according to data of the feedback optimization module.

[0024] Preferably, in an embodiment of the present invention, the output result of the optical pulse prediction model includes: a phase modulation amplitude value and a pulse width adjustment amount.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides an optical pulse control system based on ferroelectric liquid crystal; wherein, a clipping unit in an optical pulse shaping device uses a relatively low driving voltage to quickly reach the required high voltage through a ferroelectric crystal; and the clipping unit can achieve high-precision regulation, and achieves output of a narrow pulse width by applying the pulse width of the voltage stage to the ferroelectric crystal.

[0027] Furthermore, the optical pulse shaping device of the present invention can achieve high-precision control of the phase and amplitude of the optical pulse by accurately controlling the parameters of the external electric field, thereby providing support for complex pulse shaping.

[0028] Furthermore, the optical pulse control system based on ferroelectric liquid crystal in the present invention realizes intelligent, dynamic and precise control of optical pulses by combining deep learning and real-time feedback, which is particularly suitable for complex application scenarios that require precise control of pulse characteristics and rapid response.

[0029] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, and to make the above and other purposes, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 is a flow chart of the optical pulse control system based on ferroelectric liquid crystal in the present invention;

[0032] Figure 2 is a schematic structural diagram of the optical pulse shaping device of the present invention;

[0033] Figure 3 is a schematic structural diagram of the clipping unit in the present invention;

[0034] Figure 4 It is a data processing flow chart of the optical pulse control system based on ferroelectric liquid crystal in the present invention;

[0035] Figure 5 is a step diagram of the light pulse control method based on ferroelectric liquid crystal in the present invention;

[0036] Figure 6 It is a schematic diagram of the structure of the convolutional neural network model described in the present invention. DETAILED DESCRIPTION

[0037] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.

[0038] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.

[0039] In this document, the terms "first", "second", etc. are used to distinguish two different elements or parts, and are not used to limit a specific position or relative relationship. In other words, in some embodiments, the terms "first", "second", etc. can also be interchangeable.

[0040] Embodiment 1

[0041] In the prior art, electro-optical crystals such as Pockels cells and KDP require not only a relatively high driving voltage, but also high-precision voltage control, complex electronic driving circuits, and a stable high-voltage power supply, which makes the control complexity of the overall system relatively high; secondly, these electro-optical crystals require a high driving voltage, which results in high power consumption and is prone to thermal effects, which not only affect the stability and life of the device, but may also affect the overall performance of the system; and these crystals are usually bulky and require precise mechanical and optical devices for installation and adjustment, which makes the size of the entire system larger and difficult to achieve high integration.

[0042] In order to achieve high-precision and high-stability optical pulse control, such as Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a light pulse control system based on ferroelectric liquid crystal, including: a light pulse shaping device;

[0043] The optical pulse shaping device comprises a clipping unit, a plurality of laser amplifiers, a polarizing plate and a resonant cavity; wherein the clipping unit comprises a polarizing module, a ferroelectric crystal, a polarizing analyzer module and a high-voltage module.

[0044] The idea of ​​the present invention includes: ferroelectric liquid crystal (FLC) is a type of liquid crystal material with spontaneous polarization, and its molecules have bistability, that is, they can quickly switch between two different orientation states under the action of an external electric field. FLC molecules also have a certain polarization when there is no external electric field, and this polarization enables FLC to respond quickly under a very weak electric field; due to the spontaneous polarization and bistability of FLC, the response time of FLC to the electric field is very short, usually in the microsecond to nanosecond level, making it suitable for high-speed modulation applications. Therefore, in the embodiment of the present invention, ferroelectric liquid crystal is used in the optical pulse shaping device 10, and when the optical pulse passes through the ferroelectric liquid crystal, the external electric field can adjust the phase and amplitude of the optical pulse by changing the refractive index of the ferroelectric liquid crystal.

[0045] In the embodiment of the present invention, the optical pulse shaping device 10 has a specific structure as follows: Figure 2 As shown, the laser passes through the clipping unit 5 to intercept a 3ns pulse of the 10ns pulse width laser, which is amplified by the laser and then polarized by the polarizer 7. The 3ns pulse after polarization rotation enters the resonant cavity 3 and continues to be transmitted inside the laser. When passing through the semi-transparent and semi-reflective mirror 2, one percent of the laser is transmitted and enters the CCD camera 1. The CCD camera 1 is used to detect the beam quality. The clipping unit 5 is controlled by the control signal generation module to polarize the originally polarized beam, and the polarization and phase of the beam are adjusted, so that the beam quality can be better during the laser amplification process of the laser amplifier (4, 11, 13, 15, 17).

[0046] In the clipping unit 5, the ferroelectric crystal is two or more ferroelectric liquid crystals; the polarizing module and the analyzing module both include a plurality of analyzers.

[0047] In practical applications, the specific structure of the clipping unit 5 is as follows: Figure 3 As shown, the ferroelectric crystal 21 includes two identical ferroelectric liquid crystals; the polarizing module 22 and the analyzing module 19 respectively include two identical analyzers; the high-voltage module 20 is used to provide the required voltage to the ferroelectric crystal 21, and the laser passes through the polarizing module 22, and is put into the vertically or horizontally polarized laser, which is then polarized into horizontal or vertical light by the ferroelectric crystal 21 and is emitted again through the analyzing module 19.

[0048] Under the action of the ferroelectric crystal 21, the light beam can propagate through it, the phase delay in the ferroelectric crystal 21 can be adjusted by the electric field inside the crystal, and the polarization state of the linear polarized light is deflected by the ferroelectric crystal 21. This implementation requires a very narrow pulse width, and the ferroelectric crystal 21 needs to be able to quickly reach the required high voltage. Therefore, the advantages of the ferroelectric crystal 21 are reflected. The driving voltage of the ferroelectric liquid crystal (FLC) is usually low, generally between a few volts and tens of volts. The power consumption of the ferroelectric liquid crystal (FLC) is low, and the driving circuit is relatively simple, which is suitable for portable and low-power applications. In addition, another ferroelectric liquid crystal is used to achieve faster high voltage. The high-voltage module 20 provides the voltage required for the ferroelectric crystal 21 to work, and realizes a certain pulse width through the clipping control board. The timing of the pulse is synchronized and delayed with the original Q switch through the delay board. Within the pulse width range, the polarization state is deflected, and after passing through the polarization analyzer module 19 designed with the same polarization angle, it can continue to propagate. However, at the rising and falling edges on both sides of the pulse width, the ferroelectric crystal 21 does not apply voltage, and the polarization state does not deflect, so it is inconsistent with the polarization state of the polarization analyzer module 19, and this part of the pulse light cannot pass. Therefore, the light that is finally output has only the pulse width of the stage where the ferroelectric crystal 21 applies voltage, thereby achieving narrow pulse width output. The rising and falling edges of the pulse are reduced from the original 10ns to less than 1ns, and the clipping circuit board can achieve high-precision adjustment of time / delay, and achieve a full-width pulse width output of 3.5ns.

[0049] The clipping unit 5 achieves nanosecond response time through a lower driving voltage and a simple driving circuit, so that the optical pulse shaping device can achieve ultra-high-speed modulation; then, by precisely controlling the parameters of the external electric field, highly precise modulation of the optical pulse phase and amplitude is achieved.

[0050] Furthermore, in order to achieve high-precision and stable pulse control, the embodiment of the present invention further includes: a data acquisition module 20 for real-time acquisition of beam shape images and laser pulse data, a data preprocessing module 30, a deep learning module 40 and a control signal generation module 50; the data processing flow of the optical pulse control system based on ferroelectric liquid crystal is as follows: Figure 4 As shown. Among them,

[0051] The data acquisition module 20 includes a camera for acquiring a spatial distribution image of the light beam and a photodetector for measuring pulse energy and pulse width; the collected data includes the spatial distribution of the light beam, pulse width, intensity distribution, phase information, etc. In practical applications, data acquisition is achieved through a CCD camera, a high-speed photodetector and a wavefront sensor. The CCD camera is used to intercept the laser pulse image, and the photodetector is used to measure the pulse energy and pulse width.

[0052] The data preprocessing module 30 preprocesses the collected historical data to make it suitable for the input of the deep learning module 40; the preprocessing steps may include normalization, noise reduction, edge detection and image enhancement. In specific applications, image processing algorithms such as edge detection (Canny algorithm) and noise filtering (Gaussian filtering) may also be used.

[0053] In a specific application scenario, the acquired image is compared with the flattened Gaussian laser pulse image, and the image close to the Gaussian laser pulse is selected as the data set; and the pulse signal corresponding to the data set is used as the control signal data set.

[0054] The deep learning module 40 includes a convolutional neural network model, specifically Figure 6 As shown, a convolutional neural network (CNN) is used to analyze the preprocessed beam shape image and pulse data. Through multi-layer convolution and pooling operations, CNN extracts the spatial characteristics of the beam and the key characteristics of the pulse morphology. Finally, the optical pulse prediction model based on the convolutional neural network outputs the pulse signal parameters, including phase modulation amplitude and pulse width adjustment amount.

[0055] The control signal generating module 50 includes a digital signal processor and a high-speed digital-to-analog converter, which are used to convert the pulse signal parameters into specific instructions for the spatial light modulator (SLM) and the optical pulse shaping device 01. These instructions directly affect the shape and pulse width of the laser output by adjusting the phase mode of the SLM and the electric field parameters of the optical pulse shaping device 01.

[0056] Preferably, in order to dynamically adjust and continuously optimize the deep learning module 40, the embodiment of the present invention also includes: a feedback optimization module 60, which is used to collect the characteristic data of the light beam and pulse in real time, and feed the data back to the deep learning module, and continuously update the model parameters and control strategy of the deep learning module 40 to ensure the accuracy and stability of the laser output; the characteristic data includes key parameters such as beam shape, pulse width, and energy. In practical applications, dynamic adjustment and continuous optimization can be achieved with a high-sensitivity detector and a high-speed processing unit.

[0057] In summary, an embodiment of the present invention provides an optical pulse control system based on ferroelectric liquid crystal; wherein, the clipping unit in the optical pulse shaping device uses a relatively low driving voltage to quickly reach the required high voltage through the ferroelectric crystal; and the clipping unit can achieve high-precision adjustment, and realize narrow pulse width output by applying the pulse width of the voltage stage to the ferroelectric crystal.

[0058] Furthermore, the optical pulse shaping device of the present invention can achieve highly accurate control of the phase and amplitude of the optical pulse by accurately controlling the parameters of the external electric field, thereby providing support for complex pulse shaping.

[0059] Furthermore, the optical pulse control system based on ferroelectric liquid crystal in the present invention realizes intelligent, dynamic and precise control of optical pulses by combining deep learning and real-time feedback, which is particularly suitable for complex application scenarios that require precise control of pulse characteristics and rapid response.

[0060] Embodiment 2

[0061] Corresponding to the above-mentioned embodiment of the light pulse control system based on ferroelectric liquid crystal, another aspect of the embodiment of the present invention further provides a light pulse control method based on ferroelectric liquid crystal, such as Figure 5 As shown, the steps include:

[0062] S11, presetting the electric field parameters of the ferroelectric crystal in the clipping unit; and energizing the ferroelectric crystal through a voltage module according to the electric field parameters;

[0063] In the embodiment of the present invention, the electric field parameters of the ferroelectric crystal 21 are first set, and the ferroelectric crystal 21 is energized through the voltage module according to the electric field parameters, and the highly accurate modulation of the phase and amplitude of the optical pulse is achieved by precisely controlling the parameters of the applied electric field.

[0064] S12, acquiring historical data including beam spatial distribution parameters, pulse energy parameters and pulse width parameters through a data acquisition module;

[0065] In the embodiment of the present invention, the collected data includes the spatial distribution, pulse width, intensity distribution, and phase information of the light beam. In practical applications, data collection is achieved through a CCD camera, a high-speed photodetector, and a wavefront sensor. The CCD camera is used to capture the laser pulse image, and the photodetector is used to measure the pulse energy and pulse width.

[0066] S13, preprocessing the historical data to obtain modeling data of a deep learning module;

[0067] In an embodiment of the present invention, the collected historical data is preprocessed, and the preprocessing steps may include normalization, noise reduction, edge detection and image enhancement; image processing algorithms such as edge detection (Canny algorithm) and noise filtering (Gaussian filtering) may also be used. The preprocessed modeling data can make the constructed model more accurate and reliable.

[0068] In a specific application scenario, the acquired image is compared with the flattened Gaussian laser pulse image, and the image close to the Gaussian laser pulse is selected as the data set; and the pulse signal corresponding to the data set is used as the control signal data set.

[0069] S14, constructing a light pulse prediction model based on a convolutional neural network according to the modeling data;

[0070] In the embodiment of the present invention, the optical pulse prediction model is based on a convolutional neural network, specifically Figure 6 As shown in the figure, the convolutional neural network (CNN) is used to analyze the preprocessed beam shape image and pulse data. The convolutional neural network model includes: input layer, convolution layer, pooling layer, fully connected layer and output layer. Among them, the input layer is the preprocessed image and pulse data; the convolution layer is used to extract spatial features and temporal features; the pooling layer is used to reduce the feature dimension and enhance the generalization ability of the model; the fully connected layer is used to generate pulse signal parameters according to each feature; the output layer is used to output the pulse signal parameters.

[0071] Furthermore, in an embodiment of the present invention, the output of the optical pulse prediction model includes: a phase modulation amplitude value and a pulse width adjustment amount.

[0072] Preferably, in an embodiment of the present invention, the method further includes: optimizing the pulse prediction model according to the data of the feedback optimization module 60. The feedback optimization module 60 feeds back the data to the optical pulse prediction model, continuously updates the model parameters and control strategy, and ensures the accuracy and stability of the laser output; the characteristic data includes key parameters such as beam shape, pulse width, and energy.

[0073] S15. Generate a control instruction according to the output result of the optical pulse prediction model.

[0074] In the embodiment of the present invention, the output result of the optical pulse prediction model is converted into specific instructions for the spatial light modulator (SLM) and the optical pulse shaping device 01 through the control signal generation module 50. These instructions directly affect the shape and pulse width of the laser output by adjusting the phase mode of the SLM and the electric field parameters of the optical pulse shaping device 01. In practical applications, real-time and high-precision signal transmission and conversion can be ensured through the signal scheduling algorithm.

[0075] In summary, the embodiments of the present invention provide a light pulse control method based on ferroelectric liquid crystal, and construct a light pulse prediction model through the collected light pulse history data. When constructing the light pulse prediction model, a convolutional neural network is used to process the light beam shape image and pulse data, so as to generate a control signal for adjusting the light beam shape and pulse width. Through real-time feedback information, the control strategy is continuously learned and optimized to achieve precise control of the laser output characteristics; thereby achieving high-precision and high-stability light pulse control.

[0076] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An optical pulse control system based on ferroelectric liquid crystal, characterized in that: including an optical pulse shaping device; The optical pulse shaping device comprises a clipping unit, a plurality of laser amplifiers, a polarizer and a resonant cavity; wherein, The clipping unit comprises: a polarizing module, a ferroelectric crystal, a polarizing module and a high-voltage module.

2. The optical pulse control system based on ferroelectric liquid crystal according to claim 1, characterized in that: The ferroelectric crystals are two or more ferroelectric liquid crystals.

3. The optical pulse control system based on ferroelectric liquid crystal according to claim 2, characterized in that: The polarizing module and the analyzing module both include a plurality of analyzers.

4. The optical pulse control system based on ferroelectric liquid crystal according to claim 3, characterized in that: include: Data acquisition module, data preprocessing module, deep learning module and control signal generation module for acquiring beam shape images and laser pulse data in real time.

5. The optical pulse control system based on ferroelectric liquid crystal according to claim 4, characterized in that: Also includes: The feedback optimization module is used to collect the characteristic data of the light beam and the pulse in real time and feed the data back to the deep learning module.

6. The optical pulse control system based on ferroelectric liquid crystal according to claim 4, characterized in that: The data acquisition module comprises: A camera for capturing an image of the beam's spatial distribution and a photodetector for measuring the pulse energy and pulse width.

7. The optical pulse control system based on ferroelectric liquid crystal according to claim 4, characterized in that: The control signal generating module comprises: Digital signal processors and high-speed digital-to-analog converters.

8. A light pulse control method based on ferroelectric liquid crystal, used in the light pulse control system based on ferroelectric liquid crystal as claimed in any one of claims 1 to 7, characterized in that: Includes steps: S11, presetting the electric field parameters of the ferroelectric crystal in the clipping unit; and energizing the ferroelectric crystal through a voltage module according to the electric field parameters; S12, acquiring historical data including beam spatial distribution parameters, pulse energy parameters and pulse width parameters through a data acquisition module; S13, preprocessing the historical data to obtain modeling data of a deep learning module; S14, constructing a light pulse prediction model based on a convolutional neural network according to the modeling data; S15. Generate a control instruction according to the output result of the optical pulse prediction model.

9. The optical pulse control method based on ferroelectric liquid crystal according to claim 8, characterized in that: Also includes: The optical pulse prediction model is optimized according to the data of the feedback optimization module.

10. The optical pulse control method based on ferroelectric liquid crystal according to claim 9, characterized in that: The output result of the optical pulse prediction model includes: Phase modulation amplitude value and pulse width adjustment amount.

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