SPAD device radiation effect real-time online test system

Abstract

The invention relates to the technical field of space radiation effects, in particular to an SPAD device radiation effect real-time online test system, which comprises an irradiation source, an SPAD device tool, a rear-end signal processing circuit, a test platform and a laser transmitter, and is characterized in that the SPAD device tool is used for fixing an SPAD device; the irradiation source is used for irradiating the SPAD device on the SPAD device tool; the rear-end signal processing circuit is electrically connected with the SPAD device on the SPAD device tool; the test platform is electrically connected with the rear-end signal processing circuit and the laser transmitter respectively; and the laser transmitter is connected with the SPAD device on the SPAD device tool through the radiation-resistant optical fiber. According to the application, the laser emitter, the optical fiber and the shielding protection rear-end signal processing circuit are introduced into a common SPAD radiation effect research test, real-time online evaluation of a high-sensitivity SPAD device radiation effect test is realized, and output changes of the SPAD device before and after radiation under different radiation rates and different accumulation time are directly and visually displayed.

Description

Technical Field

[0001] This application relates to the technical field of space radiation effects. Specifically, it relates to a real-time online test system for the radiation effects of SPAD devices. Background Art

[0002] Lidar detectors based on single photon avalanche diodes (SPADs) achieve high detection efficiency through the avalanche multiplication effect, and have the advantages of small size, low time jitter, high detection sensitivity, fast response speed, high circuit integration, low power consumption, and low manufacturing cost. They have a series of unparalleled space application advantages compared with traditional discrete lidar systems and have outstanding application potential in the field of remote sensing technology.

[0003] Space high-energy charged particle radiation can damage semiconductor materials, resulting in a decrease in the carrier mobility of the materials and a reduction in the minority carrier lifetime, and even changing the net doping concentration of the materials, causing an increase in leakage current and a drift in the working wavelength, seriously affecting the performance of optoelectronic devices; the displacement damage effect of optoelectronic devices is obvious, and most devices are also affected by the total dose effect; both the displacement damage dose and the total ionization dose will cause a decrease in the optical response speed and an increase in the dark current of optoelectronic devices, and cause photon detection errors.

[0004] As a single photon photodetector, the working requirements of SPAD devices are high resolution and high sensitivity. However, the space radiation environment will affect the change of its detection accuracy. Therefore, before space application, it is necessary to conduct a comprehensive study on its space radiation effects. In the prior art, the evaluation of the radiation effects of SPAD devices mostly adopts an offline test method, that is, irradiating the device first and then measuring its performance changes. This method has problems such as a long test cycle and the inability to reflect the dynamic changes of the device performance during the radiation process in real time. The performance impact of the device caused by radiation may recover over time, resulting in an omission in the evaluation of the device performance. Summary of the Invention

[0005] This application provides a real-time online test system for the radiation effects of SPAD devices, which uses a radiation source to simulate the radiation of SPAD devices and monitors the output changes of the SPAD array in real time, and can truly evaluate the radiation situation of the simulated device during in-orbit flight and the impact on the device performance damage.

[0006] To achieve the above object, the present application provides a real-time online test system for the radiation effect of SPAD devices, including an irradiation source, a SPAD device tooling, a backend signal processing circuit, a test platform, and a laser emitter, where: the irradiation source, the SPAD device tooling, and the backend signal processing circuit are arranged in an irradiation chamber; the test platform and the laser emitter are arranged in a test chamber; the SPAD device tooling is used to fix the SPAD device; the irradiation source irradiates the SPDA device on the SPAD device tooling; the backend signal processing circuit is electrically connected to the SPDA device on the SPAD device tooling; the test platform is electrically connected to the backend signal processing circuit and the laser emitter respectively; the laser emitter is connected to the SPDA device on the SPAD device tooling through a radiation-resistant optical fiber.

[0007] Further, the irradiation source is a variety of radiation sources with adjustable energy, dose / flux rate.

[0008] Further, the SPAD device tooling is insensitive to irradiation and provides a fixed irradiation direction for the SPAD device.

[0009] Further, a lead brick shielding structure is arranged outside the backend signal processing circuit.

[0010] Further, the laser emitter provides a laser beam input with adjustable power density for the SPAD device through a radiation-resistant optical fiber.

[0011] The real-time online test system for the radiation effect of SPAD devices provided by the present application has the following beneficial effects:

[0012] The present application introduces a laser emitter, an optical fiber, and a shielded and protected backend signal processing circuit into the ordinary SPAD radiation effect research experiment. Utilizing the material advantages of the optical fiber such as strong radiation resistance and good stability, and the function of the normal operation of the backend circuit after shielding, it realizes the real-time online evaluation of the irradiation effect experiment of high-sensitivity SPAD devices, directly and intuitively showing the output changes of SPAD devices before and after irradiation, under different irradiation rates, and at different cumulative times, providing a reference for the radiation hardening of space SPAD devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings constituting a part of the present application are used to provide a further understanding of the present application, making other features, objects, and advantages of the present application more obvious. The schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0014] Figure 1 is a schematic diagram of the real-time online test system for the radiation effect of SPAD devices provided by the embodiments of the present application;

[0015] In the figure: 1 - irradiation source, 2 - SPAD device tooling, 3 - backend signal processing circuit, 4 - test platform, 5 - laser emitter, 6 - radiation-resistant optical fiber. Detailed implementation manners

[0016] In order to enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0017] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to describe the embodiments of this application here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0018] In this application, the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe this application and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.

[0019] Moreover, in addition to being able to represent an orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0020] In addition, the meaning of the term "plural" should be two or more.

[0021] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[0022] AsFigure 1 As shown in the figure, the present application provides a real-time online test system for the radiation effect of SPAD devices, including an irradiation source 1, a SPAD device tooling 2, a backend signal processing circuit 3, a test platform 4, and a laser transmitter 5, where: the irradiation source 1, the SPAD device tooling 2, and the backend signal processing circuit 3 are arranged in the irradiation chamber; the test platform 4 and the laser transmitter 5 are arranged in the test chamber; the SPAD device tooling 2 is used to fix the SPAD device; the irradiation source 1 irradiates the SPDA device on the SPAD device tooling 2; the backend signal processing circuit 3 is electrically connected to the SPDA device on the SPAD device tooling 2; the test platform 4 is electrically connected to the backend signal processing circuit 3 and the laser transmitter 5 respectively; the laser transmitter 5 is connected to the SPDA device on the SPAD device tooling 2 through a radiation-resistant optical fiber 6.

[0023] Specifically, the real-time online test system for the radiation effect of SPAD devices provided by the embodiments of the present application uses the irradiation source 1 to perform real-time online data processing and analysis on the response output of the SPAD device to the standard laser input signal before, during, and after the radiation simulation and irradiation test of the SPAD device, quickly and comprehensively evaluate the evolution of the output performance of the solar cell during radiation, and can form a radiation damage database of the SPAD device based on the test results of multiple irradiation tests with different energies and different fluences / fluxes, providing a more comprehensive reference for the later application of high-energy and high-intensity beam radiation protection of solar cells.

[0024] Furthermore, the irradiation source 1 is a variety of radiation sources with adjustable energy, dose / flux rate. The irradiation source 1 is used to provide irradiation to the SPAD device, and according to the actual test situation, electrons, protons, γ irradiation sources 1, etc. can be selected, and their energy, dose / flux rate can be adjusted and set.

[0025] Furthermore, the SPAD device tooling 2 is insensitive to irradiation and provides a fixed irradiation direction for the SPAD device. The SPAD device tooling 2 provides an independent mounting base for the SPAD device, enabling the SPAD device to be at the fixed irradiation direction of the irradiation source 1 and connected to the backend signal processing circuit 3 through a shielded cable.

[0026] Furthermore, a lead brick shielding structure is arranged outside the backend signal processing circuit 3. The backend signal processing module supplies power and driving signals to the SPAD device, collects and processes the signals output by the SPAD device, and transmits them to the test platform 4 in the test chamber through a cable. The backend signal processing circuit 3 is shielded by lead bricks to avoid damage to the circuit by irradiation.

[0027] Furthermore, the laser emitter 5 provides a laser beam input with adjustable power density to the SPAD device through the radiation-resistant optical fiber 6. The laser emitter 5 and the radiation-resistant optical fiber in the irradiation chamber provide a laser beam input with adjustable power density to the SPAD device. The optical fiber has good resistance to various radiation types (such as gamma rays, electron radiation, etc.). During the irradiation process, the SPAD device can receive the standard signal normally, that is, the laser emitter 5 and the optical fiber can provide a real-time online standard laser signal input to the SPAD device.

[0028] Specifically, the real-time online test system for the radiation effect of the SPAD device provided by the embodiment of the present application is adapted to various irradiation sources 1 such as gamma rays, electrons, protons, etc., and can realize the real-time online irradiation evaluation of the SPAD device. During the test process, the SPAD device array on the SPAD device fixture 2 faces the irradiation source 1 directly and receives irradiation. During the irradiation process, the SPAD device can work online, receive the standard laser signal, and output the signal in real time. The backend signal processing circuit 3 constructs the output change curve of the SPAD device according to the output signal through the test platform 4.

[0029] More specifically, the test platform 4 measures and studies parameters such as the count rate, time jitter, and photon detection efficiency of the device according to the output signal. It mainly consists of modules such as an optical fiber coupler, an optical power meter, a signal generator, and a pixel readout circuit. Among them, the optical fiber coupler performs beam splitting on the irradiated laser to adjust the attenuation range, adjustment accuracy, etc. of the optical power; the optical power meter accurately measures the optical power value of the irradiated laser signal; the signal generator generates the control signals required for the normal operation and testing of the detector assembly; the pixel readout circuit reads out the signals output by the front-end circuit. Through the test platform 4, according to the real-time online output performance evaluation of the SPAD device under different energies, different fluxes, and different particle irradiations, and comparing with the data without irradiation, an output performance degradation curve is formed; thus meeting the device output performance evaluation of the SPAD under different energies, different fluxes, and different particle irradiations, and further providing complete and comprehensive output damage data support for the space application of the device.

[0030] The foregoing is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A real-time online test system for radiation effects of a SPAD device, characterized in that, It includes an irradiation source, an SPAD device tooling, a back-end signal processing circuit, a test platform, and a laser emitter, where: The irradiation source, the SPAD device tooling, and the back-end signal processing circuit are arranged in the irradiation chamber; The test platform and the laser emitter are arranged in the test chamber; The SPAD device tooling is used to fix the SPAD device; The irradiation source irradiates the SPDA device on the SPAD device tooling; The back-end signal processing circuit is electrically connected to the SPDA device on the SPAD device tooling; The test platform is electrically connected to the back-end signal processing circuit and the laser emitter respectively; The laser emitter is connected to the SPDA device on the SPAD device tooling through a radiation-resistant optical fiber.

2. The real-time online test system for radiation effect of the SPAD device according to claim 1, characterized in that The irradiation source is a variety of radiation sources with adjustable energy, dose / flux rate.

3. The real-time online test system for radiation effect of the SPAD device according to claim 2, wherein The SPAD device tooling is insensitive to irradiation and provides a fixed irradiation direction for the SPAD device.

4. The real-time online test system for radiation effect of the SPAD device according to claim 3, characterized in that, A lead brick shielding structure is arranged outside the back-end signal processing circuit.

5. The real-time online test system for radiation effects of the SPAD device according to claim 4, characterized in that, The laser emitter provides a laser beam input with adjustable power density for the SPAD device through a radiation-resistant optical fiber.

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