A SiPM array dark count suppression system and method based on multi-channel information fusion

Abstract

This invention relates to a dark count suppression system and method for a SiPM array based on multi-channel information fusion. The system includes: a signal conditioning module comprising a compensation network and N transimpedance amplifiers connected thereto. The compensation network is also connected to an N-channel SiPM array. The compensation network receives the original pulse signals from the N channels output by the SiPM array and performs zero-pole compensation on the original pulse signals of each channel. Each transimpedance amplifier amplifies the compensated original pulse signal of its corresponding channel to obtain amplified pulse signals for each channel. An analog operation module includes multiple analog multipliers connected to the transimpedance amplifiers. The analog operation module performs analog multiplication fusion operations on the amplified pulse signals of each channel using the analog multipliers to output the final pulse signal, thus achieving dark count suppression. Compared with existing technologies, this invention has advantages such as achieving multi-channel dark count suppression.

Description

Technical Field

[0001] This invention relates to the field of sensors and electronic circuits, and in particular to a dark counting suppression system and method for SiPM arrays based on multi-channel information fusion. Background Technology

[0002] Silicon photomultiplier tubes (SiPMs), as a novel type of photodetector, have shown great application potential in the field of low-light detection due to their advantages such as high gain, high sensitivity, low power consumption, and compact design. In biomedical imaging, SiPMs can be used to detect weak light signals, enabling high-sensitivity imaging of biological tissues; in lidar, SiPMs can be used to receive weak laser echo signals, achieving long-range, high-precision target detection and three-dimensional imaging; and in high-energy physics, SiPMs can be used to detect Cherenkov radiation produced by high-energy particles for particle identification and energy measurement.

[0003] However, SiPMs still face some challenges in low-light detection applications, among which dark count (DC) is a crucial factor limiting their signal-to-noise ratio (SNR) in low-light detection scenarios. Dark count refers to the output signal generated by the SiPM due to thermal excitation and other factors in the absence of incident light. Dark count reduces the SNR of the SiPM detection signal, especially in low-light detection scenarios, where its negative impact on SNR is more significant, thus limiting the detection performance of the SiPM.

[0004] Patent application CN107110985A discloses a silicon photomultiplier tube with an internal calibration circuit. This solution disables microcells with dark currents exceeding a predetermined threshold by setting a cell disable switch and a self-test circuit in each microcell, thereby reducing the overall dark count. This solution improves performance by shielding high dark count cells, but the disabled cells cannot participate in photon detection, resulting in a reduced effective detection area and affecting photon collection efficiency.

[0005] Patent application CN115524740A discloses a detection and compensation device for the irradiation damage effect of silicon photomultiplier tubes. This solution uses a voltage adjustment module to detect dark current and adjust the bias voltage, while simultaneously adaptively adjusting the signal acquisition trigger threshold based on the measured dark count noise to reduce the probability of false triggering due to noise. This solution employs digital signal processing, using threshold judgment to filter valid signals; however, threshold adjustment suffers from response delays and is difficult to accurately distinguish between real photon signals and dark count noise in extremely low light conditions.

[0006] To reduce dark counts, a common approach is to deeply cool SiPM devices, as lower temperatures effectively suppress carrier thermal motion, thereby reducing dark counts. However, this method requires additional cooling equipment, increasing system size, complexity, and cost, and its effect on suppressing dark counts is limited.

[0007] Therefore, there is an urgent need to provide a dark count suppression method that does not require cooling equipment, has significant effects, low complexity, low cost, and small size, in order to improve the signal-to-noise ratio of the output signal of the SiPM array detector and solve the application needs of SiPM in the field of weak light detection. Summary of the Invention

[0008] The purpose of this invention is to provide a dark count suppression system and method for SiPM arrays based on multi-channel information fusion that significantly suppresses dark counts.

[0009] The objective of this invention can be achieved through the following technical solutions: A dark counting suppression system for a SiPM array based on multi-channel information fusion includes a signal conditioning module and an analog computing module connected thereto. Signal conditioning module: includes a compensation network and N transimpedance amplifiers connected thereto. The compensation network is also connected to a SiPM array with N channels. The compensation network is used to receive the original pulse signals of the N channels output by the SiPM array and to perform zero-pole compensation on the original pulse signals of each channel. Each transimpedance amplifier is used to amplify the compensated original pulse signals of the corresponding channel to obtain the amplified pulse signals of each channel. Analog operation module: includes multiple analog multipliers connected to the transimpedance amplifier. The analog operation module is used to perform analog multiplication and fusion operations on the amplified pulse signals of each channel through the analog multipliers, and output the final pulse signal to achieve dark count suppression.

[0010] Furthermore, the compensation network includes a first resistor. and the first capacitor Parallel branch formed by parallel connection, second resistor One end of the parallel branch is connected to the SiPM array, and the other end is connected to the input of each transimpedance amplifier. The second resistor One end of it is connected to the connection node between the parallel branch and the input terminal of the transimpedance amplifier, and the other end is grounded.

[0011] Furthermore, each of the transimpedance amplifiers includes an operational amplifier and a feedback resistor. Front-end parasitic capacitance The feedback resistor The feedback resistor is connected between the output and inverting input of the operational amplifier, with the non-inverting input grounded. and front-end parasitic capacitance The system bandwidth of the transimpedance amplifier is connected in parallel. and feedback resistor Front-end parasitic capacitance and gain-bandwidth product The following relationship must be satisfied: , Based on the aforementioned relationship, the feedback resistor is adjusted accordingly according to the bandwidth and gain requirements. The resistance value.

[0012] Furthermore, the output voltage of the transimpedance amplifier satisfies: , In the formula, For output voltage, This is the input current of the transimpedance amplifier.

[0013] Furthermore, the plurality of analog multipliers adopt a multiplication tree structure, and the number of analog multipliers in the multiplication tree structure is: , In the formula, To simulate the number of multipliers.

[0014] Furthermore, the N channels in the SiPM array The formula for the coincidence rate is: , In the formula, for The probability of dark counting events occurring simultaneously in multiple channels. For the first Dark count rate of a single-channel SiPM array This is the time-resolved window used for compliance judgment.

[0015] Furthermore, the analog operation module also includes a unity-gain stabilized amplifier connected to the last analog multiplier to enhance the output driving capability of the final pulse signal.

[0016] Furthermore, it also includes a power supply module connected to the signal conditioning module and the analog computing module, for supplying power to the signal conditioning module, the analog computing module and the unity-gain stable amplifier.

[0017] Furthermore, the power module includes a boost converter, a first low-dropout linear regulator, a second low-dropout linear regulator, a dual-channel boost positive / negative output converter, and a buck converter. The boost converter is connected to the N-channel SiPM array and is used to provide a power supply voltage of more than 25V to the N-channel SiPM array. The buck converter, dual-channel boost positive / negative output converter, and first low-dropout linear regulator are connected in sequence, and then connected to the analog multiplier and unity-gain stable amplifier to provide the analog multiplier and unity-gain stable amplifier with a set voltage. The back end of the first low-dropout linear regulator is connected to the second low-dropout linear regulator, and then to the transimpedance amplifier to provide the transimpedance amplifier with a set and stable voltage.

[0018] This invention also provides a dark counting suppression method for SiPM arrays based on multi-channel information fusion, comprising the following steps: The original pulse signals of the N channels output by the SiPM array are received, and zero-pole compensation is performed on the original pulse signals of each channel. The compensated original pulse signals of the corresponding channels are then amplified by transimpedance to obtain the amplified pulse signals of each channel. The amplified pulse signals of each channel are subjected to analog multiplication and fusion operations to output the final pulse signal, thereby achieving dark count suppression.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention utilizes the independence of each channel of the SiPM array and the randomness of the dark count to perform simulation operation on each channel of the SiPM array, so that the dark count of the final output of the SiPM is greatly suppressed.

[0020] (2) This invention can significantly suppress dark counts at room temperature without the need for refrigeration equipment. By utilizing the principle of N-fold coincidence rate, the dark count rate of the four-channel system is reduced to [missing value]. Much smaller than the single-channel dark count rate Experimental data show that the signal-to-noise ratio of the four-channel configuration reaches 4.68 and the signal-to-back ratio reaches 11.82, which are 93.4% and 43.3% higher than those of the cooled single-channel SiPM (signal-to-noise ratio 2.42, signal-to-back ratio 8.25), respectively, significantly improving the low-light detection performance.

[0021] (3) The present invention suppresses the long tail effect of the output pulse of SiPM array by compensating the network, reduces the full width at half maximum of the pulse signal, improves the time resolution capability, and enables the system to perform better in high-speed imaging scenarios.

[0022] (4) The present invention uses analog multiplication to realize real-time hardware fusion processing of multi-channel signals. Compared with the existing digital signal processing methods of threshold adjustment or unit disabling, the response speed is faster, there is no delay, and it can accurately distinguish between real photon signals and dark counting noise.

[0023] (5) The present invention can flexibly match the bandwidth and gain requirements of different application scenarios by adjusting the feedback resistor of the transimpedance amplifier. For high bandwidth and high gain scenarios, a two-stage amplification configuration can be adopted, and the system has strong adaptability.

[0024] (6) The system structure of the present invention is simple and does not require additional cooling equipment, which reduces the size, complexity and cost of the system. It is suitable for weak light detection and imaging applications in normal temperature environment, such as two-photon microscopy, lidar, high-energy physics detection and other fields. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall system structure of the present invention; Figure 2 This is a schematic diagram of the specific structure of the signal conditioning module of the present invention; Figure 3 This is a schematic diagram illustrating the principle of multi-channel signal analog multiplication and fusion in this invention; Figure 4 This is a schematic diagram showing the comparison of the imaging effects of the SiPM system and the cooled SiPM system at the same depth in an embodiment of the present invention. In the figure, 1: SiPM array, 2: compensation network, 3: transimpedance amplifier, 4: analog multiplier, 5: unity-gain stable amplifier, 6: first low-dropout linear regulator, 7: second low-dropout linear regulator, 8: dual-channel boost positive / negative output converter, 9: buck converter, 10: boost converter. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0027] This embodiment provides a dark count suppression system for a SiPM array based on multi-channel information fusion. This system aims to utilize the independence of each channel in the SiPM array 1 and the randomness of dark counts to perform simulated calculations on each channel, thereby significantly suppressing the dark count output by the detector. Specifically, as... Figure 1 As shown, the system includes a signal conditioning module, an analog computing module, and a power supply module. The signal conditioning module and the analog computing module are connected, and the power supply module is connected to both the signal conditioning module and the analog computing module.

[0028] like Figure 2 As shown, the signal conditioning module includes a compensation network 2 and N transimpedance amplifiers 3 connected thereto. The compensation network 2 is also connected to an N-channel SiPM array.

[0029] The SiPM array 1 allows each channel to be read out independently, with noise levels independent between each channel, and each channel outputs a raw pulse signal that does not interfere with each other.

[0030] The root cause of the long-tailed pulse effect in the output pulse of SiPM array 1 is the existence of a pole in the detector system function. This results in an exponentially decaying waveform in the optical response signal after passing through the SiPM system. Therefore, this embodiment addresses this by connecting a compensation network 2 after SiPM array 1. This network uses passive devices to perform zero-pole compensation on the original pulse signal of each channel, thus suppressing the tail of the original pulse signal output by SiPM array 1 to a certain extent. The compensation network 2 is specifically described as follows... Figure 2 As shown on the left, it includes a first resistor. and the first capacitor Parallel branch formed by parallel connection, second resistor One end of the parallel branch is connected to the SiPM array 1, and the other end is connected to the input terminal of each transimpedance amplifier 3. The second resistor One end of it is connected to the connection node of the parallel branch and the input terminal of the transimpedance amplifier 3, and the other end is grounded.

[0031] Secondly, the N transimpedance amplifiers 3 in the signal conditioning module amplify the multi-channel signals of the SiPM array 1 after processing, while meeting the bandwidth and gain requirements. For example... Figure 2 As shown on the right, each transimpedance amplifier 3 includes an operational amplifier and a feedback resistor. Front-end parasitic capacitance Feedback resistor The feedback resistor is connected between the output and inverting input of the operational amplifier, with the non-inverting input grounded. and front-end parasitic capacitance Parallel connection. Transimpedance amplifier 3 system bandwidth and feedback resistor Front-end parasitic capacitance The relationship between the gain-bandwidth product (GBP) and the gain-bandwidth product is shown in the following formula: , The output voltage of transimpedance amplifier 3 satisfies: , In the formula, For output voltage, This is the input current of transimpedance amplifier 3.

[0032] The gain-bandwidth product is a constant for a single operational amplifier; therefore, gain and bandwidth are negatively correlated. For applications with low bandwidth requirements and high gain requirements, the gain can be increased. For applications with high bandwidth requirements and low gain requirements, the size can be reduced. For scenarios requiring high gain and bandwidth, a smaller amplifier needs to be used in the transimpedance amplifier circuit. Furthermore, a second-stage amplification was designed at the rear end of the transimpedance amplifier 3 to meet the high bandwidth and high gain requirements of the amplifier system.

[0033] like Figure 1 As shown, the analog operation module includes multiple analog multipliers 4 connected to the transimpedance amplifier 3, and a unity-gain stable amplifier 5 (buffer) connected to the last analog multiplier 4.

[0034] The function of multiple analog multipliers 4 is to input the amplified multi-channel signal into multiple high-bandwidth analog multipliers 4 for analog multiplication and fusion operations. Since the pulse signals of each channel are approximated as the logic levels of a bandwidth-limited system, the analog multiplication operation of each channel signal is approximated as an AND operation of the logic levels of each channel represented by dark counts or photon counts. The retained pulse signals are photon pulses and probability-suppressed dark count pulses.

[0035] To ensure real-time computation while using as few analog multipliers as possible, a multiplication tree structure is adopted. Assume the number of channels is... Specifically, the number of two-input analog multipliers used is 4. Satisfy the following formula: , Assume the light source is uniformly distributed across the entire SiPM array 1. When the light source emits photons, multiple channels will simultaneously generate photon counting pulses. These photon pulses are retained and recorded after analog multiplication. For dark counting pulses, their occurrence time is random; therefore, the probability of multiple channels simultaneously generating dark counting pulses at the same time is very low. Consequently, the number of dark counting pulses retained after analog multiplication is smaller than the original number of dark counting pulses. Taking four channels as an example, the principle is illustrated in the attached diagram. Figure 3 As shown.

[0036] In this system, the process of simulating multiplication by inputting SiPM signals from multiple channels into the multiplication tree is approximated as the logic levels representing dark counts or photon counts in multiple channels entering a multi-input AND gate for a logical AND operation. When the sample is irradiated by a pulsed laser and produces fluorescence, multiple photosensitive targets can receive photons, so the logic levels of the AND gates input to multiple channels are all "1", and the result of the AND operation is still "1", thus the photon event is preserved. For dark count events, due to the random independence of thermal excitation, the probability of concurrently generating four logic "1s" is negligible. By employing this multi-channel concurrent conformance logic, the system significantly reduces the probability of dark counts being preserved, successfully achieving effective suppression of dark counts.

[0037] For example For channel SiPM array 1, Each channel can be considered as Each independent detector, according to Formula for the probability of coincidence: , yes The probability of dark counting events occurring simultaneously in multiple detectors For the first Dark count rate (in Hertz) of a single channel SiPM. It is the time resolution window (unit: seconds) used for compliance judgment, and in this application it is the dead time of SiPM array 1.

[0038] Assumption In the SiPM array 1, the dark count rate of each channel corresponds to the same photosensitive chip, that is... And the dark count rate of each channel ( The range is generally ).when When it is smaller, it is obvious that it can be obtained The dark count rate was greatly reduced.

[0039] For the results of the above analog multiplication fusion operation, a voltage follower is built using a high-bandwidth unity-gain stable amplifier 5 to buffer the output and enhance the output driving capability.

[0040] like Figure 1As shown, the power supply module includes a boost converter 10, a first low-dropout linear regulator 6, a second low-dropout linear regulator 7, a dual-channel boost positive / negative output converter, and a buck converter 9. The boost converter 10 is connected to the N-channel SiPM array 1 to provide a low-noise high-voltage power supply of 25V or higher to the N-channel SiPM array 1. The buck converter 9, the dual-channel boost positive / negative output converter 8, and the first low-dropout linear regulator 6 are connected sequentially, and then connected to the analog multiplier 4 and the unity-gain stable amplifier 5 to provide a set and stable voltage to the analog multiplier 4 and the unity-gain stable amplifier 5. The rear end of the first low-dropout linear regulator 6 is connected to the second low-dropout linear regulator 7, and then connected to the transimpedance amplifier 3 to provide a set and stable voltage to the transimpedance amplifier 3. Finally, the power supply module provides a low-noise high-voltage power supply of 25V or higher to the SiPM array 1 through its graded voltages, and provides low-noise positive and negative power supplies to the analog multiplier 4, the transimpedance amplifier 3, and the unity-gain stable amplifier 5.

[0041] The final pulse signal output above can be connected to the data acquisition device to complete the data acquisition.

[0042] Using the above-described suppression system, this embodiment takes a channel-based SiPM array as an example. The suppression steps of the above-described suppression system include: Step S1: Obtain a four-channel SiPM array 1. The signal of each channel can be read out independently, and the original pulse signals output by each channel are independent of each other and will not affect each other. Step S2: Use passive components according to the attached... Figure 2 The compensation network 2 shown suppresses the signal tail of the original pulse signal output by SiPM array 1 in step S1, thereby reducing the full width at half maximum (FWHM) of the pulse signal. Through compensation network 2, the system can achieve better performance in high-speed scenarios.

[0043] Step S3: In this embodiment, the Analog Devices LTC6268-10 chip is used as transimpedance amplifier 3 to amplify the output signals of the four channels of SiPM array 1. The LTC6268-10 is a 4GHz ultra-low bias current FET input operational amplifier from Analog Devices, featuring excellent performance such as ultra-low input bias current, low input parasitic capacitance, high gain-bandwidth product, high slew rate, and low noise. The circuit topology of transimpedance amplifier 3 is shown in the attached figure. Figure 2 As shown.

[0044] Specifically, the implementation of step S3 includes steps S3.1 to S3.3: Step S3.1: For applications with low bandwidth requirements but high gain requirements, use a larger feedback resistor. A transimpedance amplifier 3 can meet the requirements; Step S3.2: For applications with high bandwidth requirements and low gain requirements, use a smaller feedback resistor. A transimpedance amplifier 3 can meet the requirements; Step S3.3: For applications with high bandwidth and high gain requirements, use a smaller feedback resistor. The first stage of amplification is performed by the transimpedance amplifier 3, and the second stage of amplification is performed by a high-bandwidth amplifier connected after the transimpedance amplifier 3 (a circuit topology of non-inverting or inverting amplifier can be used) to meet the requirements of high bandwidth and high gain. Step S4: The four-channel signal, after transimpedance amplification, needs to be multiplied by analog multiplier 4 to obtain a single-channel multiplication output. Analog multiplier 4 uses the AD835 chip from Analog Devices. The AD835 is a 250MHz four-quadrant voltage output multiplier manufactured by Analog Devices, featuring high bandwidth, high input impedance, high output current capability, and low noise. The number of analog multipliers 4 used is... ; For example, the four channels of the four-channel SiPM array 1 can be considered as four independent detectors, according to the fourfold coincidence rate formula: , It is the probability that all four detectors will simultaneously experience a dark counting event. , , , The dark count rates (in Hertz) for the four channels of the SiPM array 1 are respectively. It is the time-resolved window (unit: seconds) used for conformity judgment, that is, when the time difference between multiple channel dark counts or photon counts is within a certain range. When the counts are within a certain range, these counts are considered to have occurred simultaneously. In this example, This refers to the dead time of the SiPM device.

[0045] The analog multiplication fusion operation using three analog multipliers is as follows: the analog multiplication operation is approximated by the SiPM signal input from the four channels into the multiplication tree, where the logic levels representing dark counts or photon counts in the four channels are entered into a four-input AND gate for a logical AND operation. When the sample is irradiated by a pulsed laser and produces fluorescence, all four photosensitive targets can receive photons, so the logic levels of the four channel input AND gates are all "1", and the result of the AND operation is still "1", thus the photon event is preserved. For dark count events, due to the random independence of thermal excitation, the probability of simultaneously generating four logic "1s" is extremely low.

[0046] Assuming that the dark count rate of each channel in the four-channel SiPM array 1 is consistent with that of the corresponding photosensitive chip, i.e. For a typical SiPM (taking a 3mm x 3mm size as an example), the dark count rate of each channel satisfies the following relationship: ( The range is generally Then it is obvious that we can get .

[0047] The system proposed in this embodiment uses a four-channel SiPM array 1 to record the final photon pulses through analog multiplication. This is done for two reasons: 1. It significantly reduces the dark count at the detector output. 2. It reduces the full width at half maximum (FWHM) of the recorded photon pulses, resulting in better performance in high-speed scanning imaging scenarios. Step S5: In this example, the output buffer uses the Analog Devices ADA4857-1 chip. The ADA4857-1 is a unity-gain stable amplifier with excellent characteristics such as high speed, low distortion, and low noise. The output of the analog multiplier 4 is connected to the input of the output buffer to obtain a voltage output with ADC driving capability. Step S6: For the SiPM array 1 in step S1, the transimpedance amplifier 3 in step S3, the analog multiplier 4 in step S4, and the output buffer in S5, a suitable power supply is required to power the relevant chips.

[0048] Specifically, the implementation of step S6 includes steps S6.1 to S6.3: Step S6.1: For SiPM array 1, the required supply voltage varies depending on the model. Hamamatsu series SiPM array 1 requires a supply voltage of 40V-64V. Other manufacturers' SiPM array 1 supply voltage ranges from 25V-35V. Since the SiPM array 1 requires a relatively high supply voltage, a Boost circuit (boost converter 10) is needed to provide it (taking Onsemi MICROFC-30035 as an example). Step S6.2: For analog multiplier 4 (taking AD835 as an example) and output buffer (taking ADA4857-1 as an example), both require a positive and negative 5V low noise power supply. Therefore, a positive and negative 5V low dropout regulator (LDO) needs to be connected to the back end of the dual-channel boost positive / negative output converter 8 for voltage regulation. Step S6.3: For transimpedance amplifier 3 (taking LTC6268-10 as an example), a low-noise power supply of ±2.5V is required. Therefore, a ±2.5V LDO is connected to the ±5V LDO for voltage regulation. A schematic diagram of the power supply section in step S5 is attached. Figure 1 As shown; Step S7: Connect the output signal from step S5 to the acquisition device to complete the acquisition. (Appendix) Figure 4 This paper presents a comparison of the imaging performance of the proposed SiPM system (based on the Sharplight TP3050) and a cooled SiPM (based on the Hamamatsu C13852-3050GD) at the same depth in two-photon microscopy (from left to right: cooled SiPM, uncooled single-channel SiPM, uncooled dual-channel SiPM array, and uncooled four-channel SiPM array). It can be seen that the SiPM system of this invention has a significant advantage over the cooled SiPM imaging at room temperature. The signal-to-background ratio (SBR) and signal-to-noise ratio (SNR) of the imaging results are shown in Appendix Table 1. The formulas for calculating SBR and SNR are as follows: , , in The average value of the region of interest. This is the average value of the background area. The standard deviation of the background region.

[0049] Table 1 Comparison of signal-to-background ratio and signal-to-noise ratio under different channel number configurations. Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0050] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A dark counting suppression system for a SiPM array based on multi-channel information fusion, characterized in that, It includes a signal conditioning module and an analog computing module connected to it. Signal conditioning module: includes a compensation network and N transimpedance amplifiers connected thereto. The compensation network is also connected to a SiPM array with N channels. The compensation network is used to receive the original pulse signals of the N channels output by the SiPM array and to perform zero-pole compensation on the original pulse signals of each channel. Each transimpedance amplifier is used to amplify the compensated original pulse signals of the corresponding channel to obtain the amplified pulse signals of each channel. Analog operation module: includes multiple analog multipliers connected to the transimpedance amplifier. The analog operation module is used to perform analog multiplication and fusion operations on the amplified pulse signals of each channel through the analog multipliers, and output the final pulse signal to achieve dark count suppression.

2. The SiPM array dark counting suppression system based on multi-channel information fusion according to claim 1, characterized in that, The compensation network includes a first resistor. and the first capacitor Parallel branch formed by parallel connection, second resistor One end of the parallel branch is connected to the SiPM array, and the other end is connected to the input of each transimpedance amplifier. The second resistor One end of it is connected to the connection node between the parallel branch and the input terminal of the transimpedance amplifier, and the other end is grounded.

3. The SiPM array dark counting suppression system based on multi-channel information fusion according to claim 1, characterized in that, Each of the transimpedance amplifiers includes an operational amplifier and a feedback resistor. Front-end parasitic capacitance The feedback resistor The feedback resistor is connected between the output and inverting input of the operational amplifier, with the non-inverting input grounded. and front-end parasitic capacitance The system bandwidth of the transimpedance amplifier is connected in parallel. and feedback resistor Front-end parasitic capacitance and gain-bandwidth product The following relationship must be satisfied: ， Based on the aforementioned relationship, the feedback resistor is adjusted accordingly according to the bandwidth and gain requirements. The resistance value.

4. The SiPM array dark counting suppression system based on multi-channel information fusion according to claim 3, characterized in that, The output voltage of the transimpedance amplifier satisfies: ， In the formula, For output voltage, This is the input current of the transimpedance amplifier.

5. The SiPM array dark counting suppression system based on multi-channel information fusion according to claim 1, characterized in that, The multiple analog multipliers adopt a multiplication tree structure, and the number of analog multipliers in the multiplication tree structure is: ， In the formula, To simulate the number of multipliers.

6. The SiPM array dark counting suppression system based on multi-channel information fusion according to claim 1, characterized in that, The N-channel of the SiPM array The formula for the coincidence rate is: ， In the formula, for The probability of dark counting events occurring simultaneously in multiple channels. For the first Dark count rate of a single-channel SiPM array This is the time-resolved window used for compliance judgment.

7. The SiPM array dark counting suppression system based on multi-channel information fusion according to claim 1, characterized in that, The analog computing module also includes a unity-gain stabilized amplifier connected to the last analog multiplier to enhance the output driving capability of the final pulse signal.

8. The SiPM array dark counting suppression system based on multi-channel information fusion according to claim 7, characterized in that, It also includes a power supply module connected to the signal conditioning module and the analog computing module, for supplying power to the signal conditioning module, the analog computing module and the unity-gain stable amplifier.

9. A SiPM array dark counting suppression system based on multi-channel information fusion according to claim 8, characterized in that, The power supply module includes a boost converter, a first low-dropout linear regulator, a second low-dropout linear regulator, a dual-channel boost positive / negative output converter, and a buck converter. The boost converter is connected to the N-channel SiPM array and is used to provide a power supply voltage of more than 25V to the N-channel SiPM array. The buck converter, dual-channel boost positive / negative output converter, and first low-dropout linear regulator are connected in sequence, and then connected to the analog multiplier and unity-gain stable amplifier to provide the analog multiplier and unity-gain stable amplifier with a set voltage. The back end of the first low-dropout linear regulator is connected to the second low-dropout linear regulator, and then to the transimpedance amplifier to provide the transimpedance amplifier with a set and stable voltage.

10. A dark counting suppression method for SiPM arrays based on multi-channel information fusion, characterized in that, Includes the following steps: The original pulse signals of the N channels output by the SiPM array are received, and zero-pole compensation is performed on the original pulse signals of each channel. The compensated original pulse signals of the corresponding channels are then amplified by transimpedance to obtain the amplified pulse signals of each channel. The amplified pulse signals of each channel are subjected to analog multiplication and fusion operations to output the final pulse signal, thereby achieving dark count suppression.

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