X-ray communication device and method based on laser-driven matrix photocathode

Abstract

The application provides an X-ray communication device and method based on a laser-driven matrix photocathode. The device is applied to the technical field of X-ray tubes and comprises a laser control circuit, a matrix transmission photocathode array, a collimating microchannel plate, a matrix transmission anode target array, a vacuum tube shell and a beryllium window. The method comprises: generating a dynamic pattern, loading data information to be input into an optical signal; and exciting photoelectron emission with spatial resolution characteristics at a corresponding photocathode pixel area; each channel cluster is aligned with a single photocathode pixel at the front end; after the electrons enter the microchannel, continuous secondary electron emission occurs under the action of the electric field on the inner wall of the channel, and an avalanche effect is generated; and through mechanisms such as bremsstrahlung radiation, a bundle of microfocus X-rays is generated at each target point. In this way, the technical problems of the X-ray source in the prior art, such as the limitation in spatial coding capability, response speed, integration degree and communication dimension, can be solved.

Description

Technical Field

[0001] This invention relates to the field of X-ray tube technology, and in particular to an X-ray communication device and method based on a laser-driven matrix photocathode. Background Technology

[0002] Traditional X-ray tubes, employing thermionic cathodes to emit electrons, suffer from inherent limitations such as slow response speed (microseconds), high power consumption, and difficulties in miniaturization and integration, significantly hindering their application in high-speed communication. While field emission cathodes (cold cathodes) have improved response speed, they still face challenges such as poor emission uniformity over large areas, insufficient stability, and complex driving circuits. Therefore, photocathodes based on the photoelectric effect are considered an ideal choice for achieving high-speed, controllable, and highly integrated X-ray sources. In specific communication scenarios with high requirements for confidentiality and anti-interference, such as deep-sea exploration, in vivo medical device communication, and communication within shielded environments, the strong penetrating power of X-rays makes them a highly promising communication medium. However, current X-ray communication technology primarily achieves information transmission by modulating the intensity or energy of a single X-ray beam, resulting in limited bandwidth and difficulty in meeting the demands of large data transmission volumes.

[0003] Currently, research on photocathodes mainly focuses on the development of single-point photocathodes, and large-scale array applications have not yet been achieved. This is primarily due to several technical challenges. First, the design and fabrication of photocathode arrays place extremely high demands on micro- and nano-fabrication technologies, resulting in complex and costly processes. For example, preparing photocathode materials with high efficiency and stability requires precise thin-film deposition and surface treatment techniques. Fabricating them into high-density arrays further necessitates overcoming challenges in micron- and nanometer-level patterning, etching, and integration to ensure the independence and performance consistency of each unit. Second, the design of the drive and control system for photocathode arrays is complex, especially ensuring the independence and consistency of each unit in high-density arrays, which is a key technological bottleneck. Traditional X-ray tubes typically use simple DC or high-voltage pulse power supplies, while array-type X-ray sources require independent addressing and modulation of each pixel or subarray to achieve spatially coded communication. This necessitates complex microelectronic control circuits and precise timing management to avoid crosstalk and ensure precise synchronous response from each emitting unit.

[0004] Traditional X-ray sources, including hot cathodes and field emission cold cathodes, can typically only generate and control a single or a limited number of X-ray beams simultaneously. This results in a lack of spatial coding capabilities, limiting the capacity of communication channels. Existing X-ray communication technologies primarily transmit information by modulating the intensity or energy of X-rays. This single-dimensional coding strategy severely limits the information transmission rate and data throughput of X-ray communication systems, or XCOM systems. Existing array X-ray sources based on scanning or mechanical motion are slow and unreliable. Some methods attempting to achieve spatial control of the X-ray beam, such as scanning photocathode X-ray tubes, typically rely on mechanical moving parts (such as deflection coils or robotic arms) to change the direction or focal position of the X-ray beam. The introduction of mechanical motion increases the complexity, size, weight, and manufacturing cost of the system, and the long-term operational reliability is also poor due to wear and fatigue of mechanical components. Miniaturized, integrated array X-ray sources face challenges related to crosstalk and driving complexity. The first challenge is crosstalk: in densely packed arrays, effectively isolating adjacent emitting units to prevent mutual interference between electron beams or X-rays is crucial for achieving independent control. Secondly, there is the complexity of the drive: achieving efficient, independent, and high-speed control of tens of thousands of transmitting units requires the design of extremely complex drive circuits and control systems. Summary of the Invention

[0005] This invention provides an X-ray communication device and method based on a laser-driven matrix photocathode. Traditional X-ray tubes typically use simple DC or high-voltage pulse power supply, while array-type X-ray sources require independent addressing and modulation of each pixel or subarray to achieve spatial coding communication. This invention solves the technical problems of limitations in spatial coding capability, response speed, integration and communication dimension of existing X-ray sources.

[0006] According to a first aspect of the present invention, an X-ray communication device based on a laser-driven matrix photocathode is provided, comprising: a laser control circuit, a matrix transmission photocathode array, a collimated microchannel plate, a matrix transmission anode target array, a vacuum tube shell, and a beryllium window.

[0007] The laser control circuit is located outside the vacuum tube shell. Inside the vacuum tube shell, from left to right, are a matrix-type transmission photocathode array, a collimated microchannel plate, and a matrix-type transmission anode target array. A beryllium window is installed on the far right side of the vacuum tube shell, through which X-rays pass through the anode target array and exit.

[0008] According to a second aspect of the present invention, an X-ray communication method based on a laser-driven matrix photocathode is provided, comprising:

[0009] An integrated laser control circuit located outside the vacuum tube shell independently controls the laser pulses illuminating each photocathode pixel, generating dynamic QR codes and coded sequences, loading the data to be input into the optical signal, and exciting photoelectron emission with spatial resolution characteristics in the corresponding photocathode pixel area.

[0010] The electron pulses are collimated and multiplied, and the electron beams emitted from each pixel of the photocathode enter the collimated microchannel plate. Each microchannel cluster is aligned with the individual photocathode pixel at the front end. After entering the microchannel, the electrons undergo continuous secondary electron emission under the action of the electric field of the inner wall of the channel, producing an avalanche effect.

[0011] After collimation and multiplication, the high-intensity electron pulse bombards the corresponding matrix-type transmission anode target array; each anode target is made of high atomic number metals such as tungsten and molybdenum; the high-speed electrons interact with the target atoms, generating a microfocus X-ray beam at each target point through mechanisms such as bremsstrahlung.

[0012] Compared with existing technologies, the advantages and positive effects of this invention are:

[0013] The communication device of this invention is driven by precise control of a laser control circuit. Each photocathode pixel is driven by an independent, high-speed switching laser pulse, achieving nanosecond-level response. By independently controlling the laser pulse sequence and duration, spatial and temporal joint modulation of the X-ray signal can be achieved, generating a highly directional and controllable X-ray beam that supports complex information encoding. The joint modulation strategy greatly improves communication capacity and encoding complexity, overcoming the limitations of traditional XCOM which relies on only single-dimensional modulation. This embodiment can achieve the transmission of extremely high volumes of data per second, and the communication process is highly directional, anti-interference, and has strong penetration, showing great potential in the field of special communications (such as communication across shielded walls, communication between implanted devices and external devices, and communication between critical components of aerospace vehicles).

[0014] It should be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of the present invention, nor is it intended to restrict the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0015] The above and other features, advantages, and aspects of the various embodiments of the present invention will become more apparent from the accompanying drawings and the following detailed description. The drawings are provided for a better understanding of the invention and are not intended to limit the invention. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0016] Figure 1 A block diagram of an X-ray communication device based on a laser-driven matrix photocathode according to an embodiment of the present invention is shown;

[0017] Figure 2 A flowchart of an X-ray communication method based on a laser-driven matrix photocathode according to an embodiment of the present invention is shown;

[0018] Figure 3 A schematic diagram of the signal transmission process of an X-ray communication device based on a laser-driven matrix photocathode, which can implement embodiments of the present invention, is shown.

[0019] Figure 4 A block diagram of a matrix transmission photocathode array for an X-ray communication device based on a laser-driven matrix photocathode according to an embodiment of the present invention is shown.

[0020] Figure 5 A block diagram of a collimated microchannel plate for an X-ray communication device based on a laser-driven matrix photocathode, according to an embodiment of the present invention, is shown. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0023] Figure 1 A block diagram of an X-ray communication device 100 based on a laser-driven matrix photocathode is shown in an embodiment of the present invention. The signal transmission process is as follows: Figure 3 As shown. Matrix transmission photocathode array as... Figure 4 As shown; collimated microchannel plate Figure 5 As shown. The device 100 includes: a laser control circuit 110, a matrix-type transmission photocathode array 120, a collimated microchannel plate 130, a matrix-type transmission anode target array 140, a vacuum tube shell 150, a beryllium window 160, and an X-ray 170.

[0024] The laser control circuit 110 is located outside the vacuum tube shell 150. Inside the vacuum tube shell 150, from left to right, a matrix-type transmission photocathode array 120, a collimated microchannel plate 130, and a matrix-type transmission anode target array 140 are installed. A beryllium window 160 is installed on the far right of the vacuum tube shell 150. X-rays 170 penetrate the matrix-type transmission anode target array 140 and exit through the beryllium window 160.

[0025] In this embodiment, the laser control circuit 100 provides an independent, high-speed switchable laser source for each photocathode pixel, which is encapsulated outside the vacuum tube housing 150, enabling rapid switching control of any pixel combination within a nanosecond timescale.

[0026] The matrix-type transmissive photocathode array 120 is an electron source: a transmissive photocathode film is prepared on a transparent substrate, and the photocathode film is divided into an M×N independent pixel matrix, in which each pixel serves as an independent electron emission unit.

[0027] The collimated microchannel plate 130 has a tapered aperture in the microchannel so that it corresponds to the individual pixels of the photocathode, so that the electron beam emitted by each photocathode pixel can be precisely guided and multiplied.

[0028] The matrix-type transmission anode target array 140 corresponds to and is closely fitted with the aperture of the photocathode array pixels and the collimated structure microchannel plate 130, and is arranged in parallel in a high vacuum environment; each anode target is composed of a tiny thin film or coating made of a high atomic number metal.

[0029] Vacuum tube shell 150 and beryllium window 160: A beryllium window 160 or other low-absorption window is opened on one side of the matrix transmission anode target array 140.

[0030] The communication device in this embodiment is driven by precise control of a laser control circuit. Each photocathode pixel is driven by an independent, high-speed switching laser pulse, achieving nanosecond-level response. By independently controlling the laser pulse sequence and duration, spatial and temporal joint modulation of the X-ray signal can be achieved, generating a highly directional and controllable X-ray beam that supports complex information encoding. The joint modulation strategy greatly improves communication capacity and encoding complexity, overcoming the limitations of traditional XCOM which relies on only single-dimensional modulation. This embodiment can transmit extremely high volumes of data per second, and the communication process is highly directional, anti-interference, and has strong penetration, showing great potential in the field of special communications (such as communication across shielded walls, communication between implanted devices and external devices, and communication between critical components of aerospace vehicles).

[0031] In summary, this embodiment uses a matrix photocathode array as the electron source. The cathode array, collimated microchannel plate (MCP), and anode target array all adopt a pixel-to-pixel parallel close-fitting structure. The driving and modulation method involves precisely controlling the electron emission of each photocathode pixel through independent, high-speed switching laser pulses. The device is used to construct a matrix X-ray communication system based on dynamic spatial modulation. By independently addressing and high-speed modulating each pixel in the matrix photocathode array, an X-ray beam with dynamic spatial coding characteristics can be generated, thereby realizing parallel data transmission and complex spatial multiplexing.

[0032] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0033] The above is an introduction to the method embodiments. The following describes the solution of the present invention further through device embodiments.

[0034] Figure 2 A flowchart illustrating an X-ray communication method 200 based on a laser-driven matrix photocathode according to an embodiment of the present invention is shown. Method 200 includes:

[0035] S210: An integrated laser control circuit located outside the vacuum tube shell, which independently controls the laser pulses illuminating each photocathode pixel, generates dynamic QR codes and encoded sequence patterns, loads the data information to be input into the optical signal, and excites photoelectron emission with spatial resolution characteristics in the corresponding photocathode pixel area.

[0036] Optionally, in some embodiments, the laser control circuit provides an independent, high-speed switchable laser source for each photocathode pixel. The highly integrated design of the laser control circuit allows it to be packaged outside a vacuum tube, enabling rapid switching control of any pixel combination on a nanosecond timescale. For example, pulsed drive mode has been shown to drastically reduce the X-ray delay time from 102 ns to 75 ns, with the relative pulse broadening saturating at approximately 350 ns (±20 ns) as the gate voltage increases from 600 V to 650 V. This precise and rapid control capability allows the device to generate dynamic QR code patterns or complex communication codes, providing flexible data loading schemes for X-ray communication.

[0037] In this embodiment of the invention, the process of loading the data information to be input into the optical signal specifically includes the following steps:

[0038] S211: An integrated laser control circuit located outside the vacuum tube shell, which drives the miniature laser source of each corresponding photocathode pixel at the nanosecond level; it controls the switching and pulse modulation of the laser of each pixel, and outputs a set of laser pulse arrays that can be programmed on different pixels and pulse sequences.

[0039] S212: A laser pulse array illuminates the corresponding pixels of the matrix photocathode in the matrix-type transmissive photocathode array. Each pixel generates local photoelectron emission under laser excitation, and its switching state is synchronized with the laser pulse. By switching the brightness of different pixel combinations on a nanosecond scale, complex time-varying optical patterns such as QR codes and coding sequences are dynamically generated on the photocathode plane.

[0040] Optionally, in some embodiments, the matrix-type transmissive photocathode array (electron source) is a transmissive photocathode thin film fabricated on a transparent substrate (such as quartz, sapphire, or special glass). Its spectral response characteristics need to be precisely matched to the wavelength of the driving laser to ensure efficient photoelectric conversion. Through high-precision micro-nano fabrication processes, such as photolithography, electron beam etching combined with thin film deposition technology, this photocathode thin film can be finely divided into an M×N independent pixel matrix (64×64 or higher density), where each pixel serves as an independent electron emission unit. This pixelated design is the basis for realizing spatial encoding and parallel information transmission. The fabrication of a matrix-type transmissive photocathode array typically involves the following steps:

[0041] S2121: Substrate selection and pretreatment: Select transparent substrates with high optical transmittance, excellent thermal stability and mechanical strength, such as quartz glass or sapphire, and perform pretreatment such as cleaning and polishing on their surfaces to ensure the quality of thin film deposition.

[0042] S2122: Photocathode Thin Film Deposition: Photocathode materials are deposited on transparent substrates using techniques such as high-vacuum thermal evaporation, sputtering, or atomic layer deposition (ALD). For example, multi-alkali metal photocathodes (such as Cs-K-Sb and Cs-Na-K-Sb) are typically prepared by multi-step evaporation of different alkali metals and antimony, with strict control over the proportions of each component and the deposition temperature to obtain optimal quantum efficiency and stability. For oxide cathodes, oxide thin films can be prepared using the sol-gel method or magnetron sputtering.

[0043] S2123: Patterning and Pixelation: Advanced photolithography (such as UV lithography and deep UV lithography) or electron beam etching techniques are used to pattern the deposited photocathode film. First, photoresist is spin-coated onto the photocathode film, and then exposed and developed using a mask to form an M×N pixel array pattern. Next, reactive ion etching (RIE) or wet etching is used to remove the photocathode material from unprotected areas, forming individual pixels. The spacing between pixels is designed to account for electron beam crosstalk and electrical isolation requirements.

[0044] S2124: Electrode Lead-out and Passivation: Independent micro-electrode leads are designed for each photocathode pixel, typically formed by evaporating or sputtering metal (such as Ti / Au, Cr / Au) in combination with photolithography. After the electrode leads are completed, passivation may be required to protect the photocathode material from environmental influences and improve the long-term stability of the device.

[0045] S2125: Vacuum encapsulation: The prepared photocathode array is encapsulated together with other components in a high vacuum environment to ensure the purity of the internal environment and prevent oxidation or contamination of the photocathode material, which is crucial for maintaining its high quantum efficiency and long lifespan.

[0046] S213: The dynamic optical pattern generated on the photocathode surface, where the pulse-on and pulse-off states of each pixel directly represent binary data 1 and 0; the spatial distribution and temporal variation sequence of the dynamic optical pattern together constitute a spatial-temporal two-dimensional optical code.

[0047] S220: The electron pulses are collimated and multiplied, and the electron beams emitted from each pixel of the photocathode enter the collimated microchannel plate; each channel cluster consisting of several microchannels is aligned with the single photocathode pixel at the front end; after the electrons enter the microchannel, they undergo continuous secondary electron emission under the action of the electric field of the inner wall of the channel, producing an avalanche effect.

[0048] In this embodiment, a collimated microchannel plate (MCP) is used: a microchannel plate is a precision electron multiplier device that precisely fabricates the aperture of a microchannel into a tapered shape. This structure allows it to precisely correspond to the individual pixels of a photocathode. Typically, each photocathode pixel corresponds to several micropores, thereby enabling the electron beam emitted by each photocathode pixel to be precisely guided and multiplied, effectively preventing crosstalk of the electron beam during transmission.

[0049] Optionally, in some embodiments, the process of generating an avalanche effect specifically includes the following steps:

[0050] S2201: Low-current-density electron beams representing encoded information emitted from each pixel of the matrix photocathode are guided by an electric field into individual microchannel clusters of a collimated microchannel plate aligned with its pixels. Each microchannel cluster acts as an independent electron multiplication unit.

[0051] S2202: The incident initial electrons are accelerated by the strong electric field established by the high voltage applied to both ends of the microchannel plate. When the electrons collide with the secondary electron emission material on the inner wall of the channel at high speed, multiple secondary electrons are excited. The newly generated secondary electrons are then accelerated by the same electric field and collide with the inner wall of the channel on the opposite side again, exciting more next-generation secondary electrons to continuously and cascade repeatedly occur in the microchannel.

[0052] S2203: The continuous secondary electron emission cascade within a single microchannel causes the number of electrons to increase exponentially over millimeter-level transmission distances and in extremely short time, forming a violent, localized electron avalanche effect; hundreds of thousands to millions of microchannels achieve sub-nanosecond-level synchronous response under a unified bias field, transforming the originally weak initial electron pulse at the output of the entire microchannel board into a strong electron pulse with significantly multiplied current intensity.

[0053] S230: After collimation and multiplication, a strong electron pulse bombards the corresponding matrix-type transmission anode target array; each anode target is made of high atomic number metals such as tungsten and molybdenum; high-speed electrons interact with the target atoms, generating a micro-focus X-ray beam at each target point through mechanisms such as bremsstrahlung.

[0054] In this embodiment, a matrix-type transmission anode target array is used: the anode array, photocathode array pixels, and microchannel plate apertures are strictly corresponding and tightly fitted, and arranged in parallel in a high vacuum environment. Each anode target is composed of a tiny thin film or coating made of a high atomic number metal (such as tungsten or molybdenum). When the electron beam emitted by the corresponding photocathode pixel is multiplied by the microchannel plate and accelerated under high voltage to bombard the anode target directly opposite it, the interaction between the electrons and the target atoms generates a micro-focused X-ray beam. The transmission-type anode target structure design effectively avoids the interference effect that may occur when traditional reflective targets emit X-rays, ensuring the purity of the X-ray signal and the accuracy of the encoding.

[0055] Optionally, in some embodiments, the process of generating a microfocus X-ray beam at each target point specifically includes the following steps:

[0056] S2301: The strong electron pulse emitted from the collimated microchannel plate, after collimation and multiplication, gains extremely high kinetic energy under the acceleration of the anode high voltage and precisely bombards the metal target on the matrix transmission anode target array directly opposite it.

[0057] S2302: High-speed electrons undergo rapid deceleration or deflection in the strong Coulomb field of the atomic nuclei of the anode target, and their kinetic energy loss is mainly converted into X-ray photons of continuous energy spectrum through the bremsstrahlung mechanism.

[0058] S2303: Each bombarded anode target acts as an independent miniature X-ray source, generating a highly localized micro-focused X-ray beam. The spatial distribution of the X-ray beam corresponds to the pixel pattern of the photocathode at the front end. The high-speed electrons carrying the spatial-temporal encoded information loaded on the electron beam undergo rapid deceleration or deflection in the strong Coulomb field of the atomic nuclei of the anode target. Their kinetic energy loss is mainly converted into X-ray photons with a continuous energy spectrum through the bremsstrahlung mechanism. The spatial-temporal encoded information loaded on the electron beam is transferred and carried in the modulated X-ray signal.

[0059] This embodiment achieves a significant improvement in X-ray communication channel capacity: employing spatial coding technology, it enables a channel number proportional to the number of array pixels. Existing XCOM technologies largely rely on modulating the intensity or energy of a single X-ray beam (such as four-level pulse amplitude modulation, PAM-4), limiting the information transmission dimension and channel capacity. This embodiment utilizes a photocathode array and an external light source (such as a micro-LED or VCSEL array) to independently address and modulate the intensity of each pixel, thereby encoding the X-ray signal in the spatial dimension. The femtosecond to picosecond electron emission response speed of the photocathode, combined with the fast-switching micro-light source array, enables high-speed modulation of X-rays, meeting the bandwidth requirements for large data transmission. High-density integration and excellent pixel uniformity are achieved: this embodiment utilizes integrated packaging technology in the MCP-PMT field, enabling more effective control of material uniformity and fabrication precision, thus ensuring high consistency in the performance of each pixel in the array; high-density integration also significantly reduces the device size and weight, which is crucial for size- and weight-sensitive applications such as deep-sea, in vivo medical devices, and space communication. For example, by optimizing the photocathode material and structure and utilizing advanced micro-nano fabrication techniques, array units with uniform microstructures can be fabricated, further improving emission uniformity. Excellent stability and long lifespan: Mechanical scanning or moving parts are eliminated in favor of a fully electronically controlled matrix photocathode array; the absence of mechanical movement significantly improves system reliability and stability, reduces long-term failure rates, and is particularly suitable for communication applications with extremely high stability requirements.

[0060] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0061] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this invention does not impose any limitations on them.

[0062] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An X-ray communication device based on a laser-driven matrix photocathode, characterized in that, include: Vacuum tube shell, laser control circuit, matrix-type transmissive photocathode array, collimated microchannel plate and matrix-type transmissive anode target array, beryllium window; The laser control circuit is located outside the vacuum tube shell, and the interior of the vacuum tube shell is equipped with a matrix-type transmissive photocathode array, a collimated microchannel plate, and a matrix-type transmissive anode target array, arranged from left to right.

2. The X-ray communication device based on a laser-driven matrix photocathode according to claim 1, characterized in that, A beryllium window is installed on the far right of the vacuum tube shell. X-rays pass through the anode target array and exit through the beryllium window.

3. The X-ray communication device based on a laser-driven matrix photocathode according to claim 1, characterized in that, The laser control circuit provides a laser source for each photocathode pixel and is encapsulated outside the vacuum tube, enabling rapid switching control of any pixel combination on a nanosecond timescale.

4. The X-ray communication device based on a laser-driven matrix photocathode according to claim 1, characterized in that, A matrix-type transmissive photocathode array serves as an electron source: a transmissive photocathode film is fabricated on a transparent substrate, and the photocathode film is divided into an M×N independent pixel matrix, where each pixel serves as an independent electron emission unit.

5. The X-ray communication device based on a laser-driven matrix photocathode according to claim 1, characterized in that, The collimated microchannel plate fabricates the microchannel apertures into a tapered shape, allowing them to correspond to the individual pixels of the photocathode. This guides the electron beam emitted by each photocathode pixel and induces secondary electron emission through the strong electric field within the tapered channel, achieving electron beam 10-1 4 -10 6 A multiple increase.

6. An X-ray communication method based on a laser-driven matrix photocathode, used to implement the X-ray communication device based on a laser-driven matrix photocathode as described in any one of claims 1-5, comprising: An integrated laser control circuit located outside the vacuum tube shell independently controls the laser pulses illuminating each photocathode pixel, generating dynamic QR codes and encoded sequence patterns, loading the data information to be input into the optical signal, and exciting photoelectron emission with spatial resolution characteristics in the corresponding photocathode pixel area; The electron pulses are collimated and multiplied, and the electron beams emitted from each pixel of the photocathode enter the collimated microchannel plate; each microchannel cluster is aligned with the single photocathode pixel at the front end; After electrons enter the microchannel, they undergo continuous secondary electron emission under the influence of the electric field on the inner wall of the channel, resulting in an avalanche effect. After collimation and multiplication, the high-intensity electron pulse bombards the corresponding matrix-type transmission anode target array; each anode target is made of high atomic number metals such as tungsten and molybdenum; the high-speed electrons interact with the target atoms, generating a microfocus X-ray beam at each target point through the bremsstrahlung mechanism.

7. The X-ray communication method based on a laser-driven matrix photocathode according to claim 6, characterized in that, The process of loading the data to be input into the optical signal includes the following steps: An integrated laser control circuit located outside the vacuum tube shell drives the miniature laser source of each corresponding photocathode pixel at the nanosecond level; it controls the switching and pulse modulation of the laser of each pixel, and outputs a set of laser pulse arrays that can be programmed on different pixels and pulse sequences. A laser pulse array illuminates the corresponding pixels of the matrix photocathode in the matrix transmission photocathode array. Each pixel generates local photoelectron emission under laser excitation, and its switching state is synchronized with the laser pulse. By switching the brightness of different pixel combinations on a nanosecond scale, a time-varying optical pattern is dynamically generated on the photocathode plane. The dynamic optical pattern generated on the photocathode surface, the pulse and no-pulse states of each pixel directly represent binary data 1 and 0; the spatial distribution and temporal change sequence of the dynamic optical pattern together constitute the spatial-temporal two-dimensional code of optics.

8. The X-ray communication method based on a laser-driven matrix photocathode according to claim 6, characterized in that, The fabrication of a matrix-type transmissive photocathode array includes the following steps: Select a transparent substrate and clean and polish its surface; deposit photocathode material on the transparent substrate; for oxide cathodes, prepare oxide thin films using the sol-gel method or magnetron sputtering method; Photoresist is spin-coated onto a photocathode film, and exposed and developed using a photomask to form an M×N pixel array pattern; the photocathode material in unprotected areas is removed to form individual pixels; an independent microelectrode lead is designed for each photocathode pixel and formed using photolithography; after the electrode leads are completed, passivation is performed. The prepared photocathode array and other components are encapsulated in a high vacuum environment.

9. The X-ray communication method based on a laser-driven matrix photocathode according to claim 6, characterized in that, The process that generates an avalanche effect includes the following steps: The low-current-density electron beams, representing encoded information, emitted from each pixel of the matrix photocathode are guided by an electric field into the independent microchannel clusters of the collimated microchannel plate aligned with their pixels; each channel cluster, consisting of several microchannels, serves as an independent electron multiplication unit. The incident initial electrons are accelerated by the strong electric field established by the high voltage applied to both ends of the microchannel plate on the inner wall of the channel. When the electrons collide with the secondary electron emission material on the inner wall of the channel at high speed, multiple secondary electrons are excited. The newly generated secondary electrons are then accelerated by the same electric field and collide with the inner wall of the channel on the opposite side again, exciting more next-generation secondary electrons to repeat continuously and in a cascade manner in the microchannel. The continuous secondary electron emission cascade within a single microchannel causes the number of electrons to increase exponentially over millimeter-scale transmission distances and in extremely short time periods, forming a violent, localized electron avalanche effect. Hundreds of thousands to millions of microchannels achieve sub-nanosecond-level synchronous response under a unified bias field, transforming the originally weak initial electron pulse at the output of the entire microchannel plate into a strong electron pulse with significantly multiplied current intensity.

10. The X-ray communication method based on a laser-driven matrix photocathode according to claim 6, characterized in that, The process of generating a microfocus X-ray beam at each target point includes the following steps: The strong electron pulse emitted from the collimated microchannel plate, after collimation and multiplication, gains extremely high kinetic energy under the acceleration of the anode high voltage of ≥30 kV, and bombards the metal target on the matrix transmission anode target array directly opposite it. High-speed electrons undergo rapid deceleration or deflection in the strong Coulomb field of the atomic nuclei of the anode target; Each bombarded anode target acts as an independent miniature X-ray source, generating a highly localized micro-focused X-ray beam. The spatial distribution of the X-ray beam corresponds to the front-end photocathode pixel pattern, transferring and carrying the spatial-temporal encoded information loaded on the electron beam in a low-interference, high-integration manner within the modulated X-ray signal.

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