Device for testing performance of array type single-photon detector

Abstract

The utility model relates to a device for testing the performance of an array type single-photon detector, which aims to solve the technical problem that the existing means for testing the performance of the array type single-photon detector is not mature yet, and adopts the technical scheme that the device comprises an adjustable light source module, a beam expanding module, a testing module and a data analyzing and processing module, the adjustable laser emitter emits laser, the laser is reflected and attenuated by the three reflectors and the two attenuators and then enters the beam expanding module, the beam expanding module comprises two plano-convex lenses and an adjustable lens sleeve and is located on a reflected light path, and the testing module is a micro-lens array located on the light path. The array type single-photon detector and the optical fiber power meter are respectively connected with the array type single-photon detector and the optical fiber power meter; and a time-dependent single-photon counter in the data analysis processing module is electrically connected with the array single-photon detector and the computer respectively. According to the utility model, through testing the detection efficiency, the detection efficiency consistency, the dark count, the saturation count rate, the dead time, the time jitter and the overall time jitter of the array type single-photon detector, the performance of the array type single-photon detector is comprehensively represented.

Description

Technical Field

[0001] The utility model belongs to the technical field of single-photon detector testing, and in particular relates to a device for testing the performance of array-type single-photon detectors. Background Art

[0002] As a highly sensitive photoelectric detection device, single-photon detectors are widely used in fields such as quantum communication, optical imaging, medical imaging, and spectral analysis. Due to their efficient detection capabilities for single-photon events, such devices are becoming increasingly important in basic scientific research and emerging technologies. However, the currently commonly used single-pixel single-photon detectors have some limitations in performance, which affects their effectiveness in a wider range of applications. First, single-pixel single-photon detectors cannot achieve direct imaging. This means that in many application scenarios, it is still necessary to rely on traditional scanning optical paths to obtain image information, resulting in increased system complexity and slower response speeds. In addition, the saturation count rate of single-pixel detectors is relatively low, which limits their detection capabilities in high signal intensity environments.

[0003] To address these issues, researchers are actively developing array-based single-photon detectors. Compared to single-pixel detectors, array-based detectors utilize multiple detection units working together to achieve direct imaging, eliminating the need for traditional scanning methods and significantly reducing system complexity. Furthermore, the array design significantly increases the system's saturation count rate, enhancing the signal-to-noise ratio in high-signal environments. This improvement makes array-based single-photon detectors more robust in extreme environments, enabling them to meet the needs of demanding applications.

[0004] However, despite the numerous technological advantages of arrayed single-photon detectors, specialized devices and methods for comprehensively evaluating their performance are currently lacking. This evaluation is not only crucial for optimizing the design of arrayed single-photon detectors but also provides the necessary theoretical and practical support for their widespread adoption in practical applications. Therefore, developing an effective testing device to systematically evaluate the performance of arrayed single-photon detectors has become an important and pressing issue. Addressing this issue will lay a solid foundation for the further development of arrayed single-photon detectors and promote their application in cutting-edge fields such as quantum technology. Utility Model Content

[0005] The purpose of the utility model is to solve the above problems and provide a device for testing the performance of array-type single-photon detectors.

[0006] In order to solve this technical problem, the technical solution adopted by the present invention is:

[0007] Construct a test device for the performance of an array single-photon detector, including an adjustable light source module, a beam expansion module, a test module, and a data analysis and processing module;

[0008] The adjustable light source module includes an adjustable laser emitter, a first reflector, a second reflector, a third reflector, a first attenuator, and a second attenuator, wherein the first reflector is arranged on the emission light path of the adjustable laser emitter, the second reflector is arranged on the reflection light path of the first reflector, the third reflector is arranged on the reflection light path of the second reflector, and the first attenuator and the second attenuator are arranged in sequence on the reflection light path of the third reflector;

[0009] The beam expansion module includes a first plano-convex lens, a second plano-convex lens, and an adjustable lens sleeve. The first plano-convex lens and the second plano-convex lens are arranged at two ends of the adjustable lens sleeve and are both located on the reflected light path of the third reflector. The first plano-convex lens is located on a side close to the third reflector.

[0010] The test module includes a microlens array, a fiber optic power meter, and an array-type single-photon detector. The microlens array is arranged on the light path after the beam is expanded by the beam expansion module. The fiber optic power meter is connected to the microlens array through an optical fiber. The array-type single-photon detector is also connected to the microlens array through an optical fiber.

[0011] The data analysis and processing module includes a time-correlated single-photon counter and a computer. The time-correlated single-photon counter is electrically connected to the array-type single-photon detector and the computer respectively.

[0012] Furthermore, a first aperture and a second aperture are provided on the light path between the second reflector and the third reflector.

[0013] Furthermore, the focal length of the first plano-convex lens is 10 mm, and the focal length of the second plano-convex lens is 200 mm.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. The adjustable light source module of this utility model can output continuous laser and pulsed laser to meet the requirements of different detector performance measurements;

[0016] 2. The beam expansion module of the present invention can achieve 20 times beam expansion of the light beam, and combined with the use of the fiber-optic microlens array, the system has the ability of multi-channel parallel detection, thereby improving the overall sensitivity and response speed of the system.

[0017] 3. During the operation of the utility model, a variety of performance parameters of the array-type single-photon detector can be obtained by simply operating the software, which is simple to operate and highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0019] Figure 2 This is the detection efficiency test result of the 5×5 array single-photon detector of the utility model;

[0020] Figure 3 This is the overall time jitter test result of the array-type single-photon detector of the utility model;

[0021] Figure 1 In: 1. Adjustable light source module; 2. Adjustable laser emitter; 3. First reflector; 4. Second reflector; 5. First aperture; 6. Second aperture; 7. Third reflector; 8. First attenuator; 9. Second attenuator; 10. First plano-convex lens; 11. Second plano-convex lens; 12. Adjustable lens sleeve; 13. Beam expansion module; 14. Microlens array; 15. Optical fiber; 16. Optical fiber power meter; 17. Array single-photon detector; 18. Test module; 19. Time-correlated single-photon counter; 20. Computer; 21. Data analysis and processing module. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 The figure shows a test device for the performance of an array-type single-photon detector, comprising an adjustable light source module 1, a beam expansion module 13, a test module 18 and a data analysis and processing module 21;

[0024] The adjustable light source module 1 includes an adjustable laser emitter 2, a first reflector 3, a second reflector 4, a third reflector 7, a first attenuator 8 and a second attenuator 9, wherein the first reflector 3 is arranged on the emission light path of the adjustable laser emitter 2, the second reflector 4 is arranged on the reflection light path of the first reflector 3, the third reflector 7 is arranged on the reflection light path of the second reflector 4, the first attenuator 8 and the second attenuator 9 are sequentially arranged on the reflection light path of the third reflector 7, and are used to attenuate the incident light entering the arrayed single-photon detector 17, and a first aperture 5 and a second aperture 6 are provided on the light path between the first reflector 4 and the third reflector 7. The two apertures are on the same horizontal line, and the apertures cooperate with the reflectors to adjust the collimation of the light path;

[0025] The beam expansion module 13 includes a first plano-convex lens 10, a second plano-convex lens 11, and an adjustable lens sleeve 12. The focal length of the first plano-convex lens 10 is 10 mm, and the focal length of the second plano-convex lens 11 is 200 mm. The first plano-convex lens 10 and the second plano-convex lens 11 are arranged at both ends of the adjustable lens sleeve 12 and are both located on the reflected light path of the third reflector 7. The first plano-convex lens 10 is located on the side close to the third reflector 7. After the light beam is emitted from the beam expansion module, a nearly flat-top beam can be generated.

[0026] The test module 18 includes a fiber microlens array 14, a fiber optical power meter 16, and an array-type single-photon detector 17. The fiber microlens array 14 is arranged on the light path after the beam is expanded by the beam expansion module 13. The fiber optical power meter 16 and the array-type single-photon detector 17 are connected to the fiber microlens array 14 via an optical fiber 15.

[0027] The data analysis and processing module 21 includes a time-correlated single-photon counter 19 and a computer 20. The time-correlated single-photon counter 19 is electrically connected to the arrayed single-photon detector 17 and the computer 20, respectively. Photons detected by the arrayed single-photon detector 17 are recorded by the time-correlated single-photon counter 19 and transmitted to the computer 20. Data analysis and processing are performed using data processing software within the computer 20, written in MATLAB. Parameters of the arrayed single-photon detector that can be calibrated by this device include single-photon detection efficiency, detection efficiency consistency, dark count rate, saturation count rate, dead time, timing jitter, and overall timing jitter.

[0028] like Figure 2 Shown are the detection efficiency test results of a 5×5 array single-photon detector. Detection efficiency refers to the probability that a detector responds to an incident photon. A pulsed laser is used to calibrate the detector's detection efficiency.

[0029] The detection efficiency can be expressed as Where μ is the average number of photons per pulse (this parameter is obtained by the following formula: Where P represents the pulsed laser power, h is Planck's constant, λ is the wavelength of the corresponding laser, f is the laser repetition frequency, and N is the number of photons counted per second by the detector. This allows us to obtain the detection efficiency of a single-photon detector. By testing the detection efficiency of multiple detectors in parallel, we can determine the consistency of the detection efficiency of each pixel. The detection efficiency consistency test can be characterized by variance:

[0030]

[0031] The dark count (r) of a single-photon detector refers to the phenomenon that a single-photon detector still occasionally generates a false count signal in the absence of photon input. This performance indicator can be obtained by testing the photon count under no light conditions, and its unit is s -1 .

[0032] The saturation count rate of a single-photon detector is the maximum photon count rate that the detector can accurately record per unit time. This performance parameter can be measured by gradually increasing the incident photon flux by adjusting the incident laser power (continuous laser light) and measuring the detector's output count rate. The saturation count rate is reached when the count rate stabilizes.

[0033] The dead time (DT) of a single-photon detector is the time interval between the detector detecting a photon event and the time it takes to recover and be able to detect again. During this time, the detector is insensitive to incident photons and cannot record new events. This performance parameter can be obtained by fitting the saturation count rate curve of the single-photon detector. The fitting function is: Where m is the number of input photons per second (this parameter is obtained by the following formula: ).

[0034] like Figure 3 The figure shows the overall timing jitter test results for a single-photon detector array. The timing jitter of a single-photon detector refers to the timing uncertainty of the detector's response to a single photon event, manifesting as a random deviation between the actual detection signal time and the actual photon arrival time. This performance parameter is obtained using a high-precision time-correlated single-photon counter. The timing jitter parameter is obtained by measuring the single-photon detector's instrument response function and fitting its full width at half maximum. The overall timing jitter of the detector array is then determined by measuring the timing jitter of multiple detectors in parallel.

[0035] The working process of this utility model is as follows:

[0036] When using the present invention, different output lasers are selected based on different test parameters. Pulsed lasers are used when measuring detection efficiency, detection efficiency consistency, time jitter, and overall time jitter. The repetition frequency of the pulsed laser is typically 10 MHz. A continuous laser is used when measuring dark counts, saturation count rate, and dead time. After the laser is output, the light is sequentially reflected by the first reflector 3 and the second reflector 4, passes through the first aperture 5 and the first aperture 6, and adjusts the optical path collimation. It is then reflected by the third reflector 7, and then attenuated by the first attenuator 8 and the second attenuator 9. It is then directed to a first plano-convex lens 10 with a focal length of 10 mm and a second plano-convex lens 11 with a focal length of 200 mm. After achieving a 20-fold beam expansion, a nearly flat-top beam is emitted. After passing through the microlens array 14, the beam is transmitted via an optical fiber 15 to a fiber optic power meter 16 and an arrayed single-photon detector 17, respectively. The fiber optic power meter can monitor the optical power input to the arrayed single-photon detector 17 in real time to evaluate parameters such as photon counts per pulse or photon counts per second.

[0037] The photons detected by the array single-photon detector 17 are counted by the time-correlated single-photon counter 19 and transmitted to the computer 20. The data is analyzed and processed by the data processing software in the computer 20. The data processing software is written in MATLAB. The test content includes single-photon detection efficiency, detection efficiency consistency, dark count rate, saturation count rate, dead time, time jitter and overall time jitter. Utilizing the performance characteristics of the adjustable light source module, the device has the advantages of controllable conditions, wide application and high measurement accuracy.

Claims

1. A device for testing the performance of an array-type single-photon detector, characterized in that: It comprises an adjustable light source module (1), a beam expansion module (13), a testing module (18) and a data analysis and processing module (21); The adjustable light source module (1) comprises an adjustable laser emitter (2), a first reflector (3), a second reflector (4), a third reflector (7), a first attenuator (8) and a second attenuator (9), wherein the first reflector (3) is arranged on the emission light path of the adjustable laser emitter (2), the second reflector (4) is arranged on the reflection light path of the first reflector (3), the third reflector (7) is arranged on the reflection light path of the second reflector (4), and the first attenuator (8) and the second attenuator (9) are arranged in sequence on the reflection light path of the third reflector (7); The beam expansion module (13) comprises a first plano-convex lens (10), a second plano-convex lens (11) and an adjustable lens sleeve (12), wherein the first plano-convex lens (10) and the second plano-convex lens (11) are arranged at two ends of the adjustable lens sleeve (12) and are both located on a reflected light path of a third reflector (7), and the first plano-convex lens (10) is located on a side close to the third reflector (7); The test module (18) includes a microlens array (14), a fiber optic power meter (16) and an array-type single-photon detector (17); the microlens array (14) is arranged on a light path after being expanded by a beam expansion module; the fiber optic power meter (16) is connected to the microlens array (14) via an optical fiber (15); and the array-type single-photon detector (17) is also connected to the microlens array (14) via an optical fiber (15); The data analysis and processing module (21) comprises a time-correlated single-photon counter (19) and a computer (20), and the time-correlated single-photon counter (19) is electrically connected to the array-type single-photon detector (17) and the computer (20) respectively.

2. The device for testing the performance of an arrayed single-photon detector according to claim 1, characterized in that: A first diaphragm (5) and a second diaphragm (6) are provided on the light path between the second reflector (4) and the third reflector (7).

3. The device for testing the performance of an array-type single-photon detector according to claim 1, characterized in that: The focal length of the first plano-convex lens (10) is 10 mm, and the focal length of the second plano-convex lens (11) is 200 mm.

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