A refrigeration structure and single photon detection device

Abstract

The present invention provides a refrigeration structure suitable for single-photon detection, including a plurality of refrigeration boxes arranged side by side, each refrigeration box is individually packaged, and each refrigeration box includes a radiator, a shell, a TEC refrigerator, a bias plate, an APD tube, and an optical fiber connector. The TEC refrigerator, the bias plate, and the APD tube are fixed inside the shell, and the radiator is fixed outside the shell. The optical fiber connector extends into the interior of the refrigeration box through an optical fiber connection hole, and is used to connect the optical fiber of the APD tube in the refrigeration box and the transmission optical fiber outside the refrigeration box. The present invention also provides a single-photon detection device using the refrigeration structure. The advantages of the present invention are that a plurality of refrigeration boxes are arranged side by side to form a refrigeration structure. When a certain channel fails, only the corresponding refrigeration box needs to be removed and repaired, and other channels will not be affected, thereby improving the stability of the product.

Description

Technical Field

[0001] The present invention relates to the field of quantum communication technology, and in particular to a refrigeration structure and a single-photon detection device suitable for single-photon detection. Background Art

[0002] Single-photon detectors are an important part of the quantum key distribution (QKD) system. Their function is to convert the optical quantum signal transmitted to the receiving end into an electrical signal for further processing.

[0003] At present, single-photon detectors based on avalanche photodiodes (APDs) are widely used in quantum key distribution systems. In order to meet the needs of extremely weak light detection, this type of detector must reduce the dark noise level as much as possible. Thermally excited dark noise decreases as the temperature decreases, so it is necessary to reduce the temperature of the detector to improve the performance of the detector. Early single-photon detectors used a liquid nitrogen refrigeration system. Although this method has high refrigeration efficiency, it is inconvenient to use and difficult to control the temperature. At present, semiconductor refrigeration (TEC) is mainly used in practical applications. This method is small in size and easy to control the temperature. In addition, when the single-photon detector is actually working, it requires the bias voltage at both ends of the APD to be higher than its avalanche voltage. Therefore, it is necessary to set up a bias circuit board to transmit electrical pulse signals and provide working conditions for the avalanche photodiode so that it can reach the working state, and then transmit signals to other modules through the detector control circuit board (equivalent to the main control board).

[0004] In practice, for the convenience of application, avalanche photodiodes (APDs), semiconductor cooling devices and bias circuit boards are often packaged together to form detectors, which are then used in quantum key distribution systems.

[0005] The quantum key distribution system based on BB84 protocol polarization coding requires four single-photon detectors at the receiving end for detection, because the transmitter encodes the light quantum signal according to the four different polarization states. Therefore, in the structural design of the detector, a simple and feasible solution is to directly use four independently packaged detectors. Since each detector requires a main control board for control and the detectors need to be interconnected and communicated, this method will occupy a large volume, and the wiring and installation are complicated, and the maintenance cost is high.

[0006] The disadvantages of using four independently packaged detectors in the prior art are summarized as follows:

[0007] 1. It takes up a large volume. Since it uses 4 independently packaged detectors, each detector requires a main control board for control;

[0008] 2. Poor heat dissipation. Traditional detectors use simple fan-forced cooling to dissipate heat, which cannot effectively dissipate heat in some areas where wind is blocked and difficult to circulate;

[0009] 3. The wiring and installation are complicated. The detectors need to communicate with each other, which results in the addition of a large number of wiring harnesses, making installation and maintenance difficult.

[0010] 4. High cost: Multiple main control boards and a large number of wiring harnesses increase the cost of the detector.

[0011] Therefore, a commonly used solution in the prior art is to encapsulate four APDs in one cavity, that is, a multi-channel integrated structure. The patent "Single Photon Detector and Its Low Temperature Insulation Device" with the existing application number 201921556919.3 discloses this form. The low temperature insulation device includes a fixed module, a semiconductor refrigerator, a circuit board, a pressure plate, an insulation shell, an insulation shell cover, a first sealing ring, a second sealing ring and a radiator; the insulation shell, the insulation shell cover and the radiator form a closed low temperature insulation space through the first sealing ring and the second sealing ring; the fixed module, the semiconductor refrigerator and the circuit board form a refrigeration module, and the number of refrigeration modules is at least two; the pressure plate and all the refrigeration modules are built into the low temperature insulation space, and the pressure plate fixes all the refrigeration modules to the radiator; all the refrigeration modules in the low temperature insulation space are arranged horizontally, and the two outermost refrigeration modules are away from the boundary of the low temperature insulation space. The low temperature insulation device seals multiple APD refrigeration modules in a large cavity to achieve an integrated effect.

[0012] The prior art integrates multiple avalanche photodiodes and their bias circuit boards into a refrigeration box, i.e., a multi-channel integrated structure, which has the following defects:

[0013] 1. Disassembly and maintenance are inconvenient. When one of the modules is damaged, the entire integrated refrigeration box needs to be dismantled, that is, the shell of the entire refrigeration box needs to be dismantled. The shell is connected to the bias plates, APD tubes, etc. of all channels. Therefore, the disassembly, maintenance, and installation processes are likely to cause damage to other components in the refrigeration box.

[0014] 2. Slow cooling. The heat generated by multiple TEC coolers is dissipated through a radiator. The cavity is large, resulting in slow cooling, which affects the operation of the avalanche photodiode, especially when the cavity structure remains unchanged and the number of APD cooling modules is less than 4. In the same space, a small number of cooling modules cannot guarantee the temperature in the cavity.

[0015] 3. The existing refrigeration structure has no airtightness verification function, and there are few cavity insulation measures, so the temperature inside the cavity cannot be guaranteed.

[0016] 4. In the existing solution, the fiber fusion method is used to connect the optical fiber inside the refrigeration box. This method has a complex process, the fiber fusion point is easily damaged, and the reliability is not high.

[0017] 5. In the existing solution, the connection between the optical fiber and the refrigeration cavity is sealed with sealant. This method is not easy to operate and the sealant takes a long time to cure, generally 3 to 5 days.

[0018] 6. The existing refrigeration structure has poor flexibility. When the number of channels is large (more than 4), the structure of the existing solution is very bulky. Summary of the invention

[0019] The technical problem to be solved by the present invention is how to ensure that the structure of the single photon detection device is compact and convenient for maintenance.

[0020] The present invention solves the above technical problems through the following technical solutions: a refrigeration structure, suitable for single photon detection, comprising a plurality of refrigeration boxes (10) arranged side by side, each refrigeration box (10) being individually packaged, each refrigeration box comprising a heat sink (101), a shell (102), a TEC refrigerator (103), a bias plate (104), an APD tube (109) and an optical fiber connector (112), the TEC refrigerator (103), the bias plate (104) and the APD tube (109) being fixed inside the shell (102), the radiator (101) being fixed outside the shell (102), and the optical fiber connector (112) extending into the interior of the refrigeration box (10) through an optical fiber connection hole (1025) and being used for connecting the optical fiber of the APD tube (109) inside the refrigeration box (10) and the transmission optical fiber outside the refrigeration box (10).

[0021] Multiple refrigeration boxes are arranged side by side to form a refrigeration structure. When a channel fails, only the corresponding refrigeration box needs to be removed and repaired without affecting the structure inside other refrigeration boxes, thereby improving the stability of the product.

[0022] As an optimized technical solution, the refrigeration structure further comprises an upper sealing ring (107), a lower sealing ring (113) and an upper cover plate (106); the surface of the radiator (101) is provided with a first groove (1014), the lower sealing ring (113) is placed in the first groove (1014), the lower sealing ring (113) is pressed after the shell (102) and the radiator (101) are connected, the upper surface of the shell (102) is provided with a second groove (1027), the upper sealing ring (107) is placed in the second groove (1027), and the upper sealing ring (107) is pressed between the upper surface of the shell (102) and the upper cover plate (106).

[0023] As an optimized technical solution, the shell (102) is further provided with an airtightness detection hole (1024) for performing an airtightness detection on the refrigeration box (10) after it is assembled. After the detection is completed, the airtightness detection hole (1024) is sealed with a plug (111).

[0024] As an optimized technical solution, the refrigeration box (10) is filled with a heat-insulating filler, and the inner and outer surfaces of the shell (102) are coated with an aerogel heat-insulating coating.

[0025] As an optimized technical solution, the inner and outer surfaces of the upper cover plate (106) are coated with aerogel insulation coating.

[0026] The present invention also provides a single-photon detection device using a refrigeration structure as described in any of the above schemes, the single-photon detection device also comprising a support structure, a detector control circuit board (30) and a heat dissipation structure, the support structure being used to fix the refrigeration structure, the heat dissipation structure and the detector control circuit board (30), and the detector control circuit board (30) being used to control the entire single-photon detection device.

[0027] As an optimized technical solution, the support structure includes a bottom plate (22), a left side plate (23), a right side plate (24), a front bracket (25), and a rear bracket (26); the left side plate (23) and the right side plate (24) are respectively fixed to the left and right sides of the bottom plate (22); the left and right ends of the front bracket (25) and the rear bracket (26) are respectively fixed to the left side plate (23) and the right side plate (24); and a plurality of refrigeration boxes (10) are arranged side by side between the left side plate (23) and the right side plate (24) and the front bracket (25) and the rear bracket (26).

[0028] Multiple refrigeration boxes are arranged side by side to form the refrigeration structure of the single-photon detection device. When a channel fails, only the corresponding refrigeration box needs to be removed and repaired. At this time, only the left and right side panels, front and rear brackets and other structural parts need to be removed. Other refrigeration boxes are not involved, and other channels are not affected at all. It is easy to install, disassemble, repair and test, which improves the stability of the product.

[0029] As an optimized technical solution, the support structure further comprises a tray (28), the front and rear ends of the tray (28) are respectively fixed on the front bracket (25) and the rear bracket (26), the tray (28) is located above the refrigeration box (10), and the detector control circuit board (30) is fixed above the tray (28).

[0030] As an optimized technical solution, the heat dissipation structure comprises a refrigeration box heat dissipation fan (42), a circuit board radiator (44), and a circuit board fan (46), and a refrigeration box heat dissipation fan (42) is arranged in front of each refrigeration box (10).

[0031] As an optimized technical solution, a plurality of refrigeration box cooling fans (42) are arranged side by side below the front bracket (25), a slot (252) is provided on the lower surface of the front bracket (25) corresponding to each refrigeration box cooling fan (42), and the bottom of the refrigeration box cooling fan (42) is fixed on a fixing block (27), and the fixing block (27) is fixed on the bottom plate (22) and is located between the refrigeration box (10) and the front bracket (25).

[0032] As an optimized technical solution, the circuit board radiator (44) is fixed on the detector control circuit board (30), and a circuit board fan (46) is respectively installed above the circuit board radiator (44) at a position corresponding to each refrigeration box (10).

[0033] As an optimized technical solution, the heat dissipation structure further includes an insulating pad (43) and a first thermal pad (45); the insulating pad (43) is fixed above the base plate (22) and pressed between the refrigeration box (10) and the base plate (22); and the first thermal pad (45) is installed between the detector control circuit board (30) and the circuit board radiator (44).

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] 1. Multiple refrigeration boxes are arranged side by side to form a refrigeration structure. When a channel fails, only the corresponding refrigeration box needs to be removed and repaired without affecting other channels. It is easy to install, disassemble, repair and test, which improves the stability of the product.

[0036] 2. A heat dissipation structure is set up separately for each refrigeration box and detector control circuit board, which greatly improves the heat dissipation efficiency of the system, thereby improving the working efficiency of the avalanche photodiode and the reliability of the detector control circuit board.

[0037] 3. Increase flexibility and applicability. Since each cooling module is independent, it can be combined into detectors of any channel according to needs.

[0038] 4. The refrigeration structure is equipped with an airtightness detection function, which greatly ensures the reliability of internal temperature control.

[0039] 5. Improved the internal insulation measures of the refrigeration box (using aerogel to coat the shell for insulation) and the external heat dissipation measures (heat pipes are installed on the surface of the radiator).

[0040] 6. The heat dissipation structure designed for the detector module ensures the heat dissipation of the refrigeration box module and the detector control circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is an assembly diagram of a single-photon detection device according to an embodiment of the present invention;

[0042] Figure 2 is an exploded diagram of a single photon detection device according to an embodiment of the present invention;

[0043] Figure 3 is an assembly diagram of a refrigeration box in a single-photon detection device according to an embodiment of the present invention;

[0044] Figure 4 It is an exploded view of a refrigeration box in a single-photon detection device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0046] See also Figure 1 and Figure 2 As shown, Figure 1 The following is the structural assembly diagram of the detector device. Figure 2 The single photon detection device of the present invention comprises a cooling structure, a supporting structure, a detector control circuit board 30 and a heat dissipation structure.

[0047] The cooling structure is used to cool the avalanche photodiode (APD) so that the avalanche photodiode meets the working environment requirements. The heat dissipation structure is used to discharge the heat generated by the cooling structure and the heat generated by the detector control circuit board 30. The supporting structure is used to fix the cooling structure, the heat dissipation structure, the detector control circuit board 30 and other structural components. The detector control circuit board 30 is used to control the entire single-photon detection device.

[0048] The refrigeration structure of the single-photon detection device includes a plurality of refrigeration boxes 10 arranged side by side. The plurality of refrigeration boxes are arranged side by side to form a refrigeration structure. When a channel fails, only the corresponding refrigeration box needs to be removed and repaired without affecting other channels. This embodiment is described by taking a detection device including four refrigeration boxes as an example.

[0049] Please also see Figure 3 and Figure 4 , Figure 3 It is an assembly diagram of a refrigeration box in a single-photon detection device of the present invention; Figure 4 It is an exploded view of a refrigeration box in a single photon detection device of the present invention. Each refrigeration box 10 comprises a heat sink 101, a housing 102, a TEC refrigerator 103, a biasing plate 104, a tube clamp fixing frame 105, an upper cover plate 106, an upper sealing ring 107, an APD tube clamp 108, an APD tube 109, a TEC fixing block 110, a plug 111, an optical fiber connector 112, and a lower sealing ring 113.

[0050] The radiator 101 is arranged at the lower end of the shell 102. The lower end of the radiator 101 is a heat sink 1011, and the upper end is fixed to the shell 102 by screws. Specifically, a threaded hole 1012 is provided on the edge of the upper surface of the radiator 101, and the two sides of the shell 102 have protruding mounting edges 1022. A through hole 1023 is provided on the mounting edge 1022 at a position corresponding to the threaded hole 1012. A screw (not shown in the figure) is passed through the through hole 1023 and then screwed into the threaded hole 1012 to fix the radiator 101 and the shell 102 together. A groove 1014 is provided on the surface of the radiator 101, and the threaded hole 1012 is located at the periphery of the groove 1014. A lower sealing ring 113 is placed in the groove 1014. After the shell 102 and the radiator 101 are connected, the lower sealing ring 113 is pressed. Preferably, a heat pipe (not shown in the figure) is provided on the surface of the radiator 101 to assist in heat dissipation and improve the heat dissipation measures outside the refrigeration box.

[0051] The shell 102 is also provided with an airtight detection hole 1024, which is used to perform an airtight detection on the refrigeration box 10 after it is assembled. After the detection is completed, the airtight detection hole 1024 is sealed with a plug 111. The refrigeration structure is provided with an airtight detection function, which greatly ensures the reliability of internal temperature control. The shell 102 is also provided with an optical fiber connection hole 1025, and the optical fiber connector 112 is fixed to the shell 102 by screws. The optical fiber connector 112 extends into the interior of the refrigeration box 10 through the optical fiber connection hole 1025, and is used to connect the optical fiber of the APD tube 109 in the refrigeration box 10 and the transmission optical fiber outside the refrigeration box 10.

[0052] The TEC cooler 103 is placed on the upper surface of the heat sink 101 and below the TEC fixing block 110. The upper surface of the heat sink 101 is also provided with a threaded hole 1016 located in the inner circle of the groove 1014. The edge of the TEC fixing block 110 is provided with a through hole 1103. A screw (not shown) is passed through the through hole 1103 and then screwed into the threaded hole 1016 to fix the TEC cooler 103 between the TEC fixing block 110 and the heat sink 101.

[0053] The APD tube clamp 108 is fixed on the tube clamp fixing frame 105, and can be fixed by existing methods such as screws or buckles. The APD tube 109 and the APD tube clamp 108 are fixed as a whole by existing methods such as screws or buckles. The APD tube 109 is crimped to the cold surface of the TEC cooler 103 by the tube clamp fixing frame 105. Specifically, a through hole (not shown) is provided on the tube clamp fixing frame 105, and a threaded hole corresponding to the through hole on the tube clamp fixing frame 105 is also provided on the upper surface of the radiator 101. The screw is passed through the through hole on the tube clamp fixing frame 105 and screwed into the corresponding threaded hole on the radiator 101, that is, the tube clamp fixing frame 105 is fixed to the radiator 101. The bias plate 104 is connected to the APD tube 109 to provide bias for it, and the pins of the bias plate 104 are welded to the APD tube 109. An inner step (not shown) is provided inside the housing 102 of the refrigeration box 10 at a position corresponding to the biasing plate 104 . The biasing plate 104 is received in the inner step and is screwed together with the housing 102 .

[0054] The upper surface edge of the housing 102 is provided with a threaded hole 1026, and the edge of the upper cover plate 106 is provided with a through hole 1066 corresponding to the threaded hole 1026. The screw passes through the through hole 1066 on the upper cover plate 106 and is screwed into the corresponding threaded hole 1026 on the housing 102, that is, the upper cover plate 106 is fixed to the housing 102. As an optimized solution, the upper surface of the housing 102 is provided with a groove 1027, and the threaded hole on the upper surface of the housing 102 is located at the periphery of the groove 1027. The upper sealing ring 107 is placed in the groove 1027, and the upper sealing ring 107 is pressed between the upper surface of the housing 102 and the upper cover plate 106, thereby playing a sealing role.

[0055] The refrigeration box 10 is filled with heat-insulating fillers, such as spherical foam or pearlescent sand, and the inner and outer surfaces of the shell 102 and the upper cover plate 106 are coated with aerogel heat-insulating coating for heat insulation, thereby improving the heat preservation measures inside the refrigeration box.

[0056] The supporting structure includes a bottom plate 22 , a left side plate 23 , a right side plate 24 , a front bracket 25 , a rear bracket 26 , a fixing block 27 and a tray 28 .

[0057] The left side plate 23 and the right side plate 24 are respectively fixed to the left and right sides of the bottom plate 22 by screws through the mounting holes, and the left and right ends of the front bracket 25 and the rear bracket 26 are respectively fixed to the left side plate 23 and the right side plate 24 by screws through the mounting holes. The four refrigeration boxes 10 are placed side by side between the left side plate 23 and the right side plate 24 and the front bracket 25 and the rear bracket 26, so that the front, back, left and right positions of the four refrigeration boxes 10 are all limited. The fixing block 27 is fixed to the bottom plate 22 by screws, and is located between the refrigeration box 10 and the front bracket 25, and is used to fix the cooling fan 42 of the refrigeration box. The front and rear ends of the tray 28 are respectively fixed to the front bracket 25 and the rear bracket 26, and the tray 28 is located above the refrigeration box 10. The detector control circuit board 30 is fixed above the tray 28. Specifically, a plurality of nut columns (not shown) are provided on the tray 28, and the detector control circuit board 30 is provided with through holes corresponding to the nut columns. The detector control circuit board 30 is fixed to the tray 28 by screwing the screws through the through holes on the detector control circuit board 30 into the nut columns.

[0058] The detector control circuit board 30 is an integrated detector control circuit board, which can control a plurality of refrigeration boxes 10 .

[0059] The heat dissipation structure includes a refrigeration box heat dissipation fan 42 , an insulating pad 43 , a circuit board radiator 44 , a first thermal pad 45 , a circuit board fan 46 , and a second thermal pad 47 .

[0060] A cooling box cooling fan 42 is arranged in front of each cooling box 10, and four cooling box cooling fans 42 are arranged side by side below the front bracket 25. A card slot 252 is provided on the lower surface of the front bracket 25 corresponding to each cooling box cooling fan 42. The bottom of the cooling box cooling fan 42 is fixed on the fixing block 27. After the front bracket 25 is fixed on the left plate 23 and the right plate 24, the cooling box cooling fan 42 is firmly clamped on the bottom plate 22.

[0061] The insulating pad 43 is fixed on the top of the bottom plate 22 by screws and is pressed between the refrigeration box 10 and the bottom plate 22. The insulating pad 43 is made of polytetrafluoroethylene, which has the advantages of low thermal conductivity and good high and low temperature stability.

[0062] The circuit board heat sink 44 is fixed to the detector control circuit board 30 by screws.

[0063] A first thermal pad 45 is installed between the detector control circuit board 30 and the circuit board heat sink 44 .

[0064] Four circuit board fans 46 are installed above the circuit board heat sink 44 at positions corresponding to the refrigeration box 10 .

[0065] A heat sink (not shown) is disposed in the tray 28 , and a second heat conducting pad 47 is disposed between the heat sink and the detector control circuit board 30 .

[0066] A heat dissipation structure is provided for each refrigeration box 10 and the detector control circuit board 30, which greatly improves the heat dissipation efficiency of the system, thereby improving the working efficiency of the avalanche photodiode and the reliability of the detector control circuit board. Moreover, since each refrigeration module is independent, it can be combined into a detector of any channel according to the needs. The heat dissipation structure designed for the detector module ensures the heat dissipation of the refrigeration structure and the detector control circuit board 30.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A single photon detection device, characterized in that: The device comprises a plurality of refrigeration boxes (10) arranged side by side, a support structure, a detector control circuit board (30) and a heat dissipation structure, wherein the support structure is used to fix the refrigeration box (10), the heat dissipation structure and the detector control circuit board (30), and the detector control circuit board (30) is used to control the entire single-photon detection device; Each refrigeration box (10) is individually packaged, and each refrigeration box (10) comprises a heat sink (101), a shell (102), a TEC cooler (103), a bias plate (104), an APD tube (109), and an optical fiber connector (112); the TEC cooler (103), the bias plate (104), and the APD tube (109) are fixed inside the shell (102); the heat sink (101) is fixed outside the shell (102); and the optical fiber connector (112) extends into the interior of the refrigeration box (10) through an optical fiber connection hole (1025) and is used to connect the optical fiber of the APD tube (109) inside the refrigeration box (10) and the transmission optical fiber outside the refrigeration box (10); A heat dissipation structure is separately provided for each refrigeration box (10) and the detector control circuit board (30), the heat dissipation structure comprising a refrigeration box heat dissipation fan (42), a circuit board radiator (44), and a circuit board fan (46). A refrigeration box heat dissipation fan (42) is arranged in front of each refrigeration box (10), the circuit board radiator (44) is fixed on the detector control circuit board (30), and a circuit board fan (46) is respectively installed above the circuit board radiator (44) at a position corresponding to each refrigeration box (10).

2. The single photon detection device according to claim 1, characterized in that: The refrigeration box (10) further comprises an upper sealing ring (107), a lower sealing ring (113) and an upper cover plate (106); a first groove (1014) is provided on the surface of the radiator (101); the lower sealing ring (113) is placed in the first groove (1014); the lower sealing ring (113) is pressed after the shell (102) and the radiator (101) are connected; a second groove (1027) is provided on the upper surface of the shell (102); the upper sealing ring (107) is placed in the second groove (1027); the upper sealing ring (107) is pressed between the upper surface of the shell (102) and the upper cover plate (106).

3. The single photon detection device according to claim 1, characterized in that: The shell (102) is also provided with an airtightness detection hole (1024) for performing an airtightness detection on the refrigeration box (10) after it is assembled. After the detection is completed, the airtightness detection hole (1024) is sealed with a plug (111).

4. The single photon detection device according to claim 1, characterized in that: The refrigeration box (10) is filled with a heat-insulating filler, and the inner and outer surfaces of the shell (102) are coated with an aerogel heat-insulating coating.

5. The single photon detection device according to claim 2, characterized in that: Aerogel thermal insulation coating is applied to the inner and outer surfaces of the upper cover plate (106).

6. The single photon detection device according to claim 1, characterized in that: The supporting structure comprises a bottom plate (22), a left side plate (23), a right side plate (24), a front bracket (25), and a rear bracket (26); the left side plate (23) and the right side plate (24) are respectively fixed to the left and right sides of the bottom plate (22); the left and right ends of the front bracket (25) and the rear bracket (26) are respectively fixed to the left side plate (23) and the right side plate (24); and a plurality of refrigeration boxes (10) are arranged side by side between the left side plate (23) and the right side plate (24) and the front bracket (25) and the rear bracket (26).

7. The single photon detection device according to claim 6, characterized in that: The support structure also includes a tray (28), the front and rear ends of the tray (28) are respectively fixed on the front bracket (25) and the rear bracket (26), the tray (28) is located above the refrigeration box (10), and the detector control circuit board (30) is fixed above the tray (28).

8. The single photon detection device according to claim 6, characterized in that: A plurality of refrigeration box cooling fans (42) are arranged side by side below the front bracket (25); a slot (252) is provided on the lower surface of the front bracket (25) corresponding to each refrigeration box cooling fan (42); the bottom of the refrigeration box cooling fan (42) is fixed on a fixing block (27); the fixing block (27) is fixed on the bottom plate (22) and is located between the refrigeration box (10) and the front bracket (25).

9. The single photon detection device according to claim 6, characterized in that: The heat dissipation structure further comprises an insulating pad (43) and a first thermally conductive pad (45); the insulating pad (43) is fixed above the base plate (22) and is pressed between the refrigeration box (10) and the base plate (22); and the first thermally conductive pad (45) is installed between the detector control circuit board (30) and the circuit board radiator (44).

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