A WSS-based light source-photocathode system and a regulation method

Abstract

The application discloses a kind of light source-light cathode system and regulation and control method based on WSS, it is related to electronic tube and light source regulation and control technical field.The system includes: laser light source;Wavelength selection switch module, its input end is connected with laser light source, for receiving initial laser and modulating it into multiple different wavelengths and different light intensity output laser;Output fiber array, its input end is connected with wavelength selection switch module output end, its output end is oppositely arranged with light cathode plate, for forming the dot array light spot irradiated to the different positions of light cathode plate;Temperature sensing module is the film structure of light receiving surface being set in light cathode plate, for monitoring the temperature of each light spot irradiation point;Central control system is connected with wavelength selection switch module and temperature sensing module respectively, for according to the temperature data fed back by temperature sensing module, dynamically controls wavelength selection switch module to the wavelength and light intensity distribution of each output laser, realizes the accurate regulation and control of photon energy and photoelectric effect threshold.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electron tube and light source regulated discharge devices, and particularly relates to a light source-photocathode system based on a WSS and a regulating method. BACKGROUND

[0002] In the fields of modern advanced non-destructive detection and ultrafast scientific imaging, a photocathode X-ray tube is a key component for realizing high-brightness and high-time-resolution X-ray generation. The basic working principle is as follows: a specific wavelength of laser irradiates a photocathode through a light window, and electrons are excited through photoelectric effect; the electrons are multiplied and focused to bombard an anode target material, and finally X-rays are generated.

[0003] According to the principle of photoelectric effect, the photon energy of incident laser must be higher than the excitation threshold energy (i.e. the sum of the band gap and the work function) of the photocathode material to effectively emit electrons. However, the performance and long-term reliability of the traditional photocathode X-ray tube face the following core challenges:

[0004] Firstly, the electron excitation threshold energy of the photocathode material is sensitive to temperature. During the working process, temperature fluctuations will cause the threshold energy to drift, which in turn causes the photoelectron emission efficiency to be unstable, directly affecting the brightness and long-term consistency of X-ray output; secondly, the output mode of the light source is single, which cannot adapt to the threshold energy difference at different positions of the photocathode, making it difficult to achieve efficient excitation in the whole area and restricting the improvement of beam quality; thirdly, the continuous irradiation of a single spot is easy to cause local temperature rise, leading to reduced material life and performance degradation, and may further induce threshold energy drift and emission point deformation due to thermal effects, forming a vicious cycle of continuous performance decline.

[0005] Therefore, the traditional fixed-parameter light source system cannot meet the precise and adaptive matching requirements of the photocathode for the excitation light source under dynamic working conditions. Developing a light source system that can real-time perceive the cathode state and dynamically regulate the excitation light source parameters to adapt to the temporal and spatial changes of the photocathode is the key to breaking through the technical bottleneck and realizing a high-performance photocathode X-ray tube. SUMMARY

[0006] The present application provides a light source-photocathode system based on a WSS and a regulating method to address the inherent contradiction between excitation efficiency and thermal management of the traditional light source system. The system realizes precise matching of photon energy and local threshold energy of the photocathode by real-time perception of cathode temperature and dynamic adjustment of the wavelength and intensity of each point excitation light, thereby significantly improving the electron emission efficiency while effectively suppressing material damage and performance degradation caused by photothermal effects.

[0007] In a first aspect, an embodiment of the present application provides a light source-photocathode system based on a WSS, comprising: a laser light source, a wavelength selection switch module, an output fiber array, a photocathode plate, a temperature sensing module, and a central control system.

[0008] The laser light source is used to provide initial laser light;

[0009] The input end of the wavelength selection switch module is connected with the laser light source, for receiving the initial laser light and splitting, modulating it into multiple beams of output laser light with different wavelengths and different light intensities which can be independently controlled;

[0010] The input end of the output fiber array is connected with the output end of the wavelength selection switch module, and the output end thereof is arranged opposite to the photocathode plate, for guiding multiple beams of output laser light and forming dot array light spots irradiated to different positions of the photocathode plate;

[0011] The temperature sensing module is of a thin film structure and is arranged on the light-receiving surface of the photocathode plate, for monitoring the temperature of each light spot irradiation point and irradiation area in real time;

[0012] The central control system is connected with the wavelength selection switch module and the temperature sensing module respectively, for dynamically controlling the wavelength selection switch module to allocate the wavelength and light intensity of each output laser light according to the temperature data fed back by the temperature sensing module.

[0013] As a preferred embodiment, the central control system pre-stores temperature-threshold energy correlation data of the photocathode plate, and the central control system is configured to:

[0014] receive real-time temperature data from the temperature sensing module;

[0015] calculate the target photon energy required by each position of the photocathode plate based on the temperature-threshold energy correlation data and the real-time temperature data;

[0016] control the wavelength selection switch module according to the target photon energy required by each position, so that the laser photon energy output to each position of the photocathode plate matches the corresponding target photon energy.

[0017] As a preferred embodiment, the thin film structure is a thin film type thermal sensor array plated on the light-receiving surface of the photocathode plate, wherein the material photon reaction cross section of the thin film type thermal sensor array is lower than a preset threshold.

[0018] As a preferred embodiment, a temperature data preprocessing unit connected with the temperature sensing module is further included, for preprocessing the temperature analog signal collected by the temperature sensing module and feeding back to the central control system in a preset data format, and the central control system generates control instructions for the wavelength selection switch module according to the received data;

[0019] The preset data format includes a two-dimensional array or a visual heat map, the two-dimensional array is used for internal processing of the system and comparison with a preset threshold, and the visual heat map is used for providing an intuitive temperature distribution display to a user.

[0020] As a preferred implementation, the central control system generates control instructions for the wavelength selection switch module according to the received data, including an over-threshold control instruction and a threshold energy adaptation control instruction, wherein,

[0021] The over-threshold control instruction includes: when the temperature of a certain monitoring point exceeds the corresponding preset safety threshold of the material of the point, controlling the wavelength selection switch module to reduce the light intensity of the output laser irradiating the point or adjusting it to a higher wavelength to suppress the temperature rise of the point.

[0022] The threshold energy adaptation control instruction includes: when the temperature of a certain monitoring point does not exceed the threshold but fluctuates, dynamically adjusting the laser wavelength irradiating the point according to the temperature-threshold energy correlation data to match the photon energy with the real-time threshold energy, so as to maintain the optimal photoelectric emission efficiency of the point.

[0023] As a preferred implementation, the wavelength selection switch module adopts an incident end and an exit end layout structure, and the wavelength selection switch module internally includes, along the light path, an incident optical fiber, a first electrically controlled grating, a second electrically controlled grating, an electrically controlled micromirror array, and an input end of the output optical fiber array, wherein,

[0024] The first electrically controlled grating is used for spatially angularly separating incident laser light.

[0025] The second electrically controlled grating is used for converging or mixing the separated light beams.

[0026] Each micromirror unit in the electrically controlled micromirror array is independently controllable, and is used for reflecting the light beams processed by the second electrically controlled grating to a designated input port of the output optical fiber array.

[0027] As a preferred implementation, the first electrically controlled grating is an electrically controlled scattering grating, and the second electrically controlled grating is an electrically controlled focusing grating.

[0028] In a second aspect, the embodiment of the present application also provides a light source-photocathode control method, comprising:

[0029] The temperature data of each light spot irradiating point of the photocathode plate is acquired in real time by the temperature sensing module, and the temperature data is converted into a preset format and fed back to the central control system.

[0030] Based on the temperature data and the pre-stored temperature-threshold energy correlation data, the target photon energy required for irradiating each position is determined.

[0031] The wavelength selection switch module is regulated according to the target photon energy required by each position, so that the laser photon energy output to each position of the photocathode plate matches the corresponding target photon energy.

[0032] As a preferred embodiment, the wavelength selection switch module is regulated according to the target photon energy required by each position, so that the laser photon energy output to each position of the photocathode plate matches the corresponding target photon energy, including:

[0033] The temperature of each position is compared with its preset safety threshold;

[0034] If the temperature of any position exceeds its preset safety threshold, the target laser parameter of the corresponding position is set to a cooling parameter with the primary goal of reducing the heat load of the region;

[0035] If the temperature of all points is below the safety threshold, the target laser parameter of the corresponding position is set to an efficiency optimization parameter that matches the laser photon energy with the target photon energy.

[0036] As a preferred embodiment, the pre-stored temperature-threshold energy correlation data is obtained by the following steps:

[0037] Photoelectric response tests are performed at different temperatures and different position points;

[0038] The threshold energy spatial distribution of the photocathode plate and its temperature variation relationship are calibrated and stored.

[0039] Compared with the prior art, the present application achieves the following beneficial effects:

[0040] (1) The present application relies on the temperature-threshold energy correlation model and the wavelength real-time regulation mechanism, so that the photon energy of each region of the photocathode is always accurately matched with the real-time threshold energy, maintaining the optimal excitation state, effectively solving the problem of uneven excitation efficiency of traditional systems. Compared with the traditional system with the same light source and cathode material, the electron emission efficiency is increased by 1.9 times, providing core support for high-quality X-ray output.

[0041] (2) The present application reduces the photo-thermal conversion efficiency through precise wavelength matching, which effectively inhibits local overheating from the root and avoids the accelerated degradation of the photocathode material due to thermal damage. Compared with the traditional system, the average local temperature rise of the photocathode of the present application is reduced by 67.3%, significantly delaying the material aging process and ensuring long-term stable operation of the device.

[0042] (3) The present application realizes high-density dot array excitation of the fiber array by means of the multi-channel flexible regulation and control capability of the wavelength selective switch, and covers the full area of the photocathode. The dot array density of the present application is increased by more than 200% compared with the traditional system, can be adaptively matched with the threshold energy difference of different areas, completely solves the problem of local low efficiency caused by single-point excitation, and realizes uniform and efficient excitation of the full area.

[0043] (4) The present application constructs a complete closed-loop control system of temperature monitoring-threshold energy calculation-wavelength adjustment, collects temperature data in real time through a thin film thermal sensor, drives the wavelength selective switch to dynamically adjust the parameters after rapid processing by the central control system, the response time is ms level, ensures the stability and consistency of the electron emission efficiency, and avoids the emission fluctuation caused by the lack of feedback mechanism in the traditional system.

[0044] (5) The present application integrates the advantages of excitation efficiency optimization, thermal damage inhibition, closed-loop stable regulation and control, significantly reduces the performance degradation rate of the photocathode material, and greatly improves the overall working stability and service life of the X-ray tube. Compared with the traditional system, the service life of the X-ray tube of the present application is increased by more than 1.5 times on average, effectively reduces the equipment maintenance frequency and replacement cost, and improves the economy of long-term operation of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0045] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings. The drawings are for the purpose of illustrating preferred embodiments only and are not to be construed as limiting the present application. Moreover, in the accompanying drawings, the same reference numerals are used to denote the same components throughout the several views. In the drawings:

[0046] Figure 1 is a basic structure diagram of a traditional photocathode X-ray tube provided by the embodiment of the present application;

[0047] Figure 2 is a threshold energy schematic diagram of laser energy and photocathode photoelectric effect provided by the embodiment of the present application;

[0048] Figure 3 is a whole structure diagram of a light source-photocathode system provided by the embodiment of the present application;

[0049] Figure 4 is a sensor-control system-WSS system working flowchart provided by the embodiment of the present application;

[0050] Figure 5 is a schematic diagram of a visualized thermal diagram provided by the embodiment of the present application;

[0051] Figure 6 is an internal structure diagram of a WSS provided by the embodiment of the present application;

[0052] Figure 7 This is a flowchart of a light source-photocathode control method provided in an embodiment of the present invention. Detailed Implementation

[0053] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0054] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of the operations (or steps) can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but it may also have additional steps not included in the figures. The process may correspond to a method, function, procedure, subroutine, subroutine, etc.

[0055] Example 1

[0056] like Figure 2 As shown, from the perspective of photoelectric excitation mechanism, to achieve stable and effective electron excitation, the photon energy of the incident laser must be greater than the excitation threshold energy of the photocathode material (i.e., the sum of the band gap energy and the work function). Both excessively high and low laser energy have significant adverse effects. However, if the laser energy is too high, it will cause a significant temperature rise in the photocathode material, thereby accelerating the material aging process and reducing energy utilization. Conversely, if the laser energy is too low, it will be impossible to break through the threshold and achieve stable electron emission. Therefore, in practical applications, the laser energy is usually controlled within a range slightly higher than the threshold to balance electron excitation efficiency and the lifespan of the photocathode material.

[0057] The light source system of a traditional photocathode X-ray tube is shown in the attached figure. Figure 1 As shown, however, it still faces performance and reliability bottlenecks in high-end applications. Its technical limitations are mainly concentrated in the following three aspects: First, the electron excitation threshold energy of the photocathode material is sensitive to temperature. During operation, temperature fluctuations can cause the threshold energy to drift, leading to unstable photoelectron emission efficiency and directly affecting the brightness and long-term consistency of X-ray output. Second, the light source has a single output mode, which cannot adapt to the threshold energy differences at different locations of the photocathode, making it difficult to achieve efficient excitation across the entire area and restricting the improvement of beam quality. Third, continuous irradiation of a single spot can easily cause local temperature rise, leading to a reduction in material lifespan and performance degradation. It may also induce further threshold energy drift and emission point deformation due to thermal effects, forming a vicious cycle of continuous performance degradation.

[0058] The present application aims at the inherent contradiction of traditional light source system in excitation efficiency and heat management, and provides a light source-photocathode system based on WSS, as shown in Figure 3 The overall structure of the light source-photocathode system based on WSS provided by the first embodiment of the present application is shown in the figure, which specifically comprises:

[0059] The laser light source, the wavelength selection switch module, the output fiber array, the photocathode plate, the temperature sensing module and the central control system work cooperatively to form an intelligent excitation light source system with real-time sensing and adaptive control capabilities.

[0060] The laser light source is used to generate initial continuous or pulsed laser, and the wavelength range needs to cover the main photoelectric response band of the target photocathode material.

[0061] The wavelength selection switch module (WSS) is the core optical path control component of the system, and its input end is connected with the laser light source, used to receive the initial laser and split, modulate it into multiple beams of output laser with different wavelengths and different light intensities which can be independently controlled.

[0062] The input end of the output fiber array is connected with the output end of the wavelength selection switch module (WSS), and its output end is arranged opposite to the photocathode plate, used to guide the multiple beams of output laser and form a dot array of light spots irradiated to different positions of the photocathode plate, realizing independent irradiation of different areas of the cathode surface, and the number of channels of the output fiber array can be adjusted according to the size of the photocathode plate.

[0063] The photocathode plate is made of GaAs, Cs2Te or other photoelectric conversion materials, and is a functional component for generating photoelectrons.

[0064] The temperature sensing module is a thin film structure, arranged on the light receiving surface of the photocathode plate, used to monitor the temperature of each light spot irradiation point and irradiation area in real time, and the thin film structure is a thin film temperature sensor array prepared on the light receiving surface of the photocathode plate, which corresponds to the light spot array in space; the thin film material constituting the sensor is an insulating thin film material with a photon absorption rate <1%, such as silicon nitride or aluminum oxide, which is plated on the light receiving surface of the photocathode plate by magnetron sputtering process, ensuring that it does not interfere with the photoelectric effect and the temperature measurement accuracy is ≤±0.5℃.

[0065] The central control system is communicatively connected with the wavelength selection switch module (WSS) and the temperature sensing module, used to dynamically control the wavelength and light intensity distribution of each output laser of the wavelength selection switch module according to the temperature data fed back by the temperature sensing module.

[0066] As a preferred embodiment, the system further comprises a temperature data preprocessing module connected with the temperature sensing module, for preprocessing the temperature analog signals collected by the temperature sensing module; the temperature data preprocessing unit comprises a signal amplification module, a low-pass filter module, and an analog-to-digital conversion module, for converting the analog temperature signals into a two-dimensional array (the array dimensions correspond one-to-one to the light spot array), and finally converting them into digitized data reflecting the two-dimensional spatial distribution of the surface temperature of the photocathode plate, and feeding the digitized data to the central control system in a preset data format. The preset data format includes a two-dimensional array or a visualized heat map, as shown in Figure 5 , for providing an intuitive temperature distribution display to the user.

[0067] As a preferred embodiment, before the system is enabled, a temperature-threshold energy correlation database of the photocathode plate needs to be established through pre-calibration experiments. The specific method is as follows: in a controllable temperature environment, the temperature of the photocathode plate is regulated by a semiconductor refrigeration or heating table, the laser wavelength is monitored by an optical fiber spectrometer, and the photoelectron signal is collected by a microammeter; each position point is tested repeatedly for 3 times, and the average value of the critical photon energy at this temperature is taken as the threshold energy data at this temperature, so as to calibrate the spatial distribution of the threshold energy and its variation with temperature, and pre-store this correlation data into the central control system.

[0068] As a preferred embodiment, the central control system is configured to:

[0069] receive real-time temperature data reflecting each position of the photocathode plate from the temperature sensing module;

[0070] based on the above temperature-threshold energy correlation data and real-time temperature data, calculate the target photon energy required by each position of the photocathode plate;

[0071] According to the target photon energy required by each position, the wavelength selection switch module is regulated so that the laser photon energy output to each position of the photocathode plate matches the corresponding target photon energy.

[0072] As a preferred embodiment, as shown in Figure 4 , the regulation logic of the central control system includes two core modes of over-threshold regulation and threshold energy adaptation regulation, and intelligently switches according to the real-time temperature condition:

[0073] The over-threshold regulation includes: when the temperature of a certain monitoring point exceeds the preset safety threshold of the material of the point, the wavelength selection switch module is controlled to reduce the light intensity of the output laser irradiating the point or adjust it to a higher wavelength to inhibit the temperature rise of the point. Wherein, the preset safety threshold is determined according to the characteristics of the photocathode material (for example, 600 DEG C for GaAs and 500 DEG C for Cs2Te), and the user can finally configure it according to the actual application requirements. If the user tends to maximize the device life, a lower conservative threshold can be set to preferentially control the temperature; if the user tends to pursue higher operating efficiency, a relatively higher threshold can be set to bear slightly higher thermal load within the controllable range to improve the excitation efficiency.

[0074] The threshold energy adaptive regulation instruction includes: when the temperature of a certain monitoring point does not exceed the threshold but fluctuates, the wavelength of the laser irradiating the point is dynamically adjusted according to the temperature-threshold energy correlation data, so that the photon energy matches the real-time threshold energy, so as to maintain the optimal photoelectric emission efficiency of the point.

[0075] As a preferred embodiment, as the key to realize multi-path independent regulation, the WSS module in the embodiment preferably adopts a free-space optical architecture and an opposite layout, and its internal structure diagram is as shown in Figure 6 The internal structure along the optical path includes: an incident optical fiber, a first electrically controlled grating, a second electrically controlled grating, an electrically controlled micromirror array, and an input end of the output optical fiber array, wherein,

[0076] The incident optical fiber is the light signal receiving end of the WSS and the wavelength change, is made of special optical fiber material, realizes the conversion of a single energy laser beam into a multi-wavelength laser beam, and the output end is accurately aligned with the light entrance surface of the electrically controlled scattering grating to ensure lossless incidence of the optical signal;

[0077] The first electrically controlled grating is located on the light exit side of the incident optical fiber and is an electrically controlled adjustable wavelength light splitting structure. The light exit direction corresponds to the light entrance surface of the electrically controlled focusing grating, which is used for angular separation of laser in space;

[0078] The second electrically controlled grating is located between the electrically controlled scattering grating and the electrically controlled micromirror array, and is a grating structure containing beam convergence and multi-wavelength mixing functions. Its light exit surface accurately corresponds to the mirror surface area of the electrically controlled micromirror array, and can converge or mix the target wavelength beam;

[0079] The electrically controlled micromirror array is the exit laser positioning component of the WSS, which adopts an arrayed micro electrically controlled mirror structure. The deflection angle of each micro mirror can be independently regulated by the control system. The array arrangement range corresponds to the input end of the exit optical fiber array one by one, and is connected with the control system to realize intelligent angle adjustment.

[0080] Output fiber array: the light signal output end of the WSS, using an array type fiber arrangement structure matched with the electrically controlled micromirror array, each fiber input end corresponding to a micromirror reflection unit; the number and arrangement of its fiber channels are determined according to the specific form of the photocathode, and the output end is connected to the subsequent output fiber plate.

[0081] As a preferred embodiment, the first electrically controlled grating is an electrically controlled scattering grating, and the second electrically controlled grating is an electrically controlled focusing grating.

[0082] Specifically, during operation, the incident laser first enters the wavelength selective switch (WSS), and the internal optical elements of the WSS complete the separation of the single energy laser into different wavelength lasers and the spatial separation of the different wavelength lasers; the control system accurately matches the output fibers corresponding to the different wavelength lasers by calling the pre-stored threshold energy database, and finally forms a dot array light source that can be accurately controlled on the output fiber plate. At the same time, the plate spacing between the output fiber plate and the photocathode plate is controlled within a reasonable range (50-200 pm), so as to avoid interference optical effects such as interference and diffraction of the emitted light, and to ensure the stability of excitation.

[0083] The above components are connected in series along the light signal transmission path, and through accurate alignment and reasonable layout, wavelength regulation, wave separation, wave combination and positioning emission of the single incident laser are realized.

[0084] According to the above embodiments, the following beneficial effects are achieved:

[0085] (1) The present application relies on the temperature-threshold energy correlation model and the wavelength real-time regulation mechanism, so that the photon energy of each region of the photocathode is always accurately matched with the real-time threshold energy, the optimal excitation state is maintained, and the problem of uneven excitation efficiency of the traditional system is effectively solved. Compared with the traditional system with the same light source and cathode material, the electron emission efficiency is increased by 1.9 times, which provides core support for high-quality X-ray output.

[0086] (2) The present application reduces the photo-thermal conversion efficiency through accurate wavelength matching, inhibits the local overheating phenomenon from the root, and avoids the accelerated degradation of the photocathode material due to thermal damage. Compared with the traditional system, the local temperature rise of the photocathode of the present application is reduced by an average of 67.3%, which significantly delays the aging process of the material and ensures the long-term stable operation of the device.

[0087] (3) The present application takes advantage of the multi-channel flexible regulation and control capability of the wavelength selective switch to realize high-density dot array excitation of the fiber array, covering the entire region of the photocathode. The dot array density of the present application is increased by more than 200% compared with the traditional system, which can adapt to the threshold energy difference of different regions and completely solve the problem of local low efficiency caused by single-point excitation, realizing uniform and efficient excitation of the entire region.

[0088] (4) The present application constructs a complete closed-loop control system of temperature monitoring-threshold energy calculation-wavelength adjustment, collects temperature data in real time through a thin film thermal sensor, drives the wavelength selection switch to dynamically adjust parameters after rapid processing by the central control system, responds in ms, ensures the stability and consistency of electron emission efficiency, and avoids emission fluctuations caused by the lack of feedback mechanism in traditional systems.

[0089] (5) The present application integrates the advantages of excitation efficiency optimization, thermal damage inhibition, closed-loop stable regulation, etc., significantly reduces the performance degradation rate of photocathode materials, and greatly improves the overall working stability and service life of the X-ray tube. Compared with the traditional system, the service life of the X-ray tube of the present application is increased by more than 1.5 times on average, effectively reducing the equipment maintenance frequency and replacement cost, and improving the economy of long-term operation of the equipment.

[0090] Embodiment two

[0091] Figure 7 is a flowchart of a light source-photocathode regulation method provided by the second embodiment of the present application, as shown in Figure 7 , the method 700 comprises:

[0092] S710: Real-time acquisition of temperature data of each light spot irradiation point of the photocathode plate by the temperature sensing module, and feedback of the temperature data to the central control system after conversion into a preset format.

[0093] As a preferred embodiment, the temperature data of each light spot irradiation point on the surface of the photocathode plate is collected in real time by the temperature sensing module. The collected original signal is preprocessed, including analog-digital conversion, formatting, etc., to form digital temperature distribution information available for the central control system, and is fed back to the central control system.

[0094] S720: Based on the temperature data and the pre-stored temperature-threshold energy correlation data, determining the target photon energy required for irradiating each position;

[0095] As a preferred embodiment, after the central control system receives the real-time temperature data, the pre-stored temperature-threshold energy correlation data is called. The correlation data is obtained through the following calibration steps: after system assembly or regular maintenance, photoelectric response test is carried out at different environmental temperatures and for different position points of the photocathode plate, so as to calibrate and store the spatial distribution of threshold energy and its quantitative relationship with temperature change. Based on the correlation model and the current real-time temperature, the system calculates the target photon energy required for irradiating each position of the photocathode plate.

[0096] S730: Regulating the wavelength selection switch module according to the target photon energy required for each position, so that the laser photon energy output to each position of the photocathode plate matches the corresponding target photon energy.

[0097] As a preferred embodiment, the temperature of each position is first compared with its preset safety threshold;

[0098] If the temperature of any position exceeds its preset safety threshold, the target laser parameter of the corresponding position is set to a cooling parameter which primarily aims to reduce the heat load of the region;

[0099] If the temperature of all points is below the safety threshold, the target laser parameter of the corresponding position is set to an efficiency optimization parameter which matches its laser photon energy with the target photon energy.

[0100] As a preferred embodiment, the pre-stored temperature-threshold energy correlation data is obtained by photoelectric response tests at different temperatures and different position points, and the threshold energy spatial distribution of the photocathode plate and its variation with temperature are calibrated and stored.

[0101] According to the above embodiments, the following beneficial effects are achieved:

[0102] (1) The present application can fine-tune the photon energy of incident laser at different positions and different times through pre-calibrated temperature-threshold energy correlation data and real-time temperature feedback, realize dynamic matching of photon energy and real-time threshold energy, and ensure that the photoelectric conversion of each region is at the optimal efficiency point from a physical mechanism, greatly improving the precision and intelligent level of energy utilization.

[0103] (2) The present application deeply integrates temperature sensing, model calculation and real-time driving of wavelength selection switch (WSS) through the central control system, realizes compact and efficient automatic control. This method realizes seamless connection from monitoring to regulation, significantly reduces the system complexity and dependence on external control equipment, and improves the overall reliability.

[0104] (3) The core regulation logic of the present application (temperature feedback→threshold energy calculation→wavelength matching) has universality, and by updating the temperature-threshold energy correlation data model in the central control system, the same set of hardware system can quickly adapt to photocathodes of different materials or different packaging structures, without replacing the light source or core optical components, which improves the versatility and application flexibility of the equipment, and reduces the cost and cycle of customized development for different applications.

[0105] It should be understood that various forms of flow shown above can be used to reorder, add or delete steps. For example, each step described in the present application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which is not limited herein.

[0106] The above embodiments are merely exemplary and are not intended to limit the embodiments. Based on the above description, those skilled in the art can further make modifications and variations to the embodiments. The modifications and variations do not depart from the scope of the embodiments.

Claims

1. A WSS-based light source-photocathode system, characterized by, The application relates to a laser wavelength selection and control system for a photocathode plate. The system comprises a laser light source, a wavelength selection switch module, an output fiber array, a photocathode plate, a temperature sensing module and a central control system. The laser light source is used for providing initial laser light. The input end of the wavelength selection switch module is connected with the laser light source, and the wavelength selection switch module is used for receiving the initial laser light and splitting and modulating the initial laser light into multiple beams of output laser light with different wavelengths and different light intensities which can be independently controlled. The input end of the output fiber array is connected with the output end of the wavelength selection switch module, and the output end of the output fiber array is arranged opposite to the photocathode plate and is used for guiding the multiple beams of output laser light and forming dot array light spots irradiated to different positions of the photocathode plate. The temperature sensing module is a thin film structure and is arranged on the light receiving surface of the photocathode plate and is used for monitoring the temperature of each light spot irradiation point and irradiation area in real time. The central control system is connected with the wavelength selection switch module and the temperature sensing module respectively, and is used for dynamically controlling the wavelength selection switch module to allocate the wavelength and light intensity of each output laser light according to the temperature data fed back by the temperature sensing module. The central control system pre-stores temperature-threshold energy correlation data of the photocathode plate, and the central control system is configured to: receive real-time temperature data from the temperature sensing module; calculate the target photon energy required by each position of the photocathode plate based on the temperature-threshold energy correlation data and the real-time temperature data; control the wavelength selection switch module according to the target photon energy required by each position, so that the laser photon energy output to each position of the photocathode plate matches the corresponding target photon energy. The wavelength selection switch module adopts an incident end and an emission end layout structure, and the wavelength selection switch module internally comprises, along an optical path, an incident fiber, a first electrically controlled grating, a second electrically controlled grating, an electrically controlled micromirror array and the input end of the output fiber array. The first electrically controlled grating is used for spatially separating incident laser light. The second electrically controlled grating is used for converging or mixing the separated light beams. Each micromirror unit in the electrically controlled micromirror array is independently controllable and is used for reflecting the light beams processed by the second electrically controlled grating to a specified input port of the output fiber array.

2. The system of claim 1, wherein, The thin film structure is a thin film type thermal sensor array plated on the light receiving surface of the photocathode plate, and the material photon reaction cross section of the thin film type thermal sensor array is lower than a preset threshold.

3. The system of claim 1, wherein, A temperature data preprocessing unit connected with the temperature sensing module is further arranged, and the temperature data preprocessing unit is used for preprocessing temperature analog signals collected by the temperature sensing module and feeding back the temperature analog signals to the central control system in a preset data format. The preset data format comprises a two-dimensional array or a visualized heat map, the two-dimensional array is used for internal processing of the system and comparison with a preset threshold, and the visualized heat map is used for providing a user with an intuitive temperature distribution display.

4. The system of claim 3, wherein, The central control system generates control instructions for the wavelength selection switch module according to the received data, and the control instructions comprise an over-threshold control instruction and a threshold energy adaptation control instruction. The over-threshold regulation instruction comprises: when the temperature of a certain monitoring point exceeds the preset safety threshold corresponding to the material of the point, controlling the wavelength selection switch module to reduce the light intensity of the output laser irradiating the point or adjusting it to a higher wavelength to suppress the temperature rise of the point. The threshold energy adaptive regulation instruction comprises: when the temperature of a certain monitoring point does not exceed the threshold but fluctuates, dynamically adjusting the laser wavelength irradiating the point according to the temperature-threshold energy correlation data to match the photon energy with the real-time threshold energy, so as to maintain the optimal photoelectric emission efficiency of the point.

5. The system of claim 1, wherein, The first electrically controlled grating is an electrically controlled scattering grating, and the second electrically controlled grating is an electrically controlled focusing grating.

6. A method for regulating a WSS-based light source-photocathode system, applied to the WSS-based light source-photocathode system according to any one of claims 1-5, characterized in that, It comprises: The temperature data of each spot irradiation point of the photocathode plate is obtained in real time by the temperature sensing module, and the temperature data is converted into a preset format and then fed back to the central control system; Based on the temperature data and the pre-stored temperature-threshold energy correlation data, the target photon energy required for irradiating each position is determined; According to the target photon energy required for each position, the wavelength selection switch module is regulated so that the laser photon energy output to each position of the photocathode plate matches the target photon energy corresponding to the position.

7. The method of claim 6, wherein, The wavelength selection switch module is regulated according to the target photon energy required for each position, so that the laser photon energy output to each position of the photocathode plate matches the target photon energy corresponding to the position. Comparing the temperature of each position with its preset safety threshold; If the temperature of any position exceeds its preset safety threshold, the target laser parameter of the corresponding position is set as a cooling parameter with reducing the heat load of the region as the primary goal; If the temperature of all points is below the safety threshold, the target laser parameter of the corresponding position is set as an efficiency optimization parameter that matches the laser photon energy with the target photon energy.

8. The method of claim 7, wherein, The pre-stored temperature-threshold energy correlation data is obtained by the following steps: Photoelectric response test is carried out at different temperatures and different positions; Calibrate and store the threshold energy spatial distribution of the photocathode plate and its temperature variation relationship.

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