CN210840476U - Single photon detection system - Google Patents

Abstract

The utility model discloses a single photon detection system, which relates to the technical field of quantum secret communication, and comprises an avalanche photodiode, a refrigeration and heat preservation module, a fiber coiling module, a fan, a radiator and a shell cover; the system has a front side, a back side, a left side, and a right side that are referenced; the fiber coiling module is arranged on the front side, and the refrigeration and heat preservation module is arranged on the rear side; the avalanche photodiode is arranged in the refrigeration and heat preservation module, the refrigeration and heat preservation module is provided with an optical fiber through hole, and the fiber coiling module is close to the optical fiber through hole; the radiator is arranged below the refrigeration and heat preservation module, the fan is arranged below the fiber coiling module, and an air outlet of the fan faces the radiator; and the shell cover covers the refrigeration and heat preservation module, the fiber coiling module, the fan and the radiator. The single photon detection system has the advantages that the modules are assembled into the shell, the modules are connected compactly, the size is small, the movement is convenient, and the heat dissipation effect is good.

Description

Single photon detection system

Technical Field

The application relates to the technical field of quantum secret communication, in particular to a single photon detection system.

Background

In the research of quantum information science, a large number of single photons are used as carriers of quantum information, so that the single photon detection technology plays an important role in the research. At present, single photon detection is also one of core technologies in the field of quantum secure communication, and a single photon detection system can detect a single photon carrying quantum information, convert the single photon into an electric signal for output, and extract the quantum information carried by the single photon by means of coincidence measurement, counting and the like.

Single photon detection in the field of quantum secure communications mainly employs avalanche photodiodes (APD tubes) as their detection elements. The working mode of the device is that a bias voltage higher than avalanche voltage is added on an APD tube to enable the APD tube to be in a Geiger mode, when a single photon reaches the APD tube, the APD tube is triggered to generate self-sustaining avalanche with a certain probability to generate larger avalanche current, and the detection of the APD tube is completed through a post-stage processing circuit, so that the detection of the single photon is realized. The avalanche photodiode applied to single photon detection needs to work at a low temperature of-40 to-50 ℃ so as to improve the sensitivity and the working efficiency of the avalanche photodiode. Therefore, when the single photon detection system works, a working environment which can refrigerate and can keep low temperature all the time, namely a refrigeration and heat preservation module, is needed. The existing refrigeration design usually adopts a multistage refrigeration semiconductor refrigeration chip, the chip is provided with a cold surface and a hot surface which are opposite to each other, the hot surface needs to be connected with a radiator for heat dissipation, and the existing single photon detection system adopts more radiating fins for accelerating heat dissipation, has larger volume and unsatisfactory heat dissipation effect. In addition, according to the requirements of system design, the optical fiber connected to the APD tube needs to be configured with a certain length of pigtail, and a specific optical fiber coiling module is needed to accommodate the pigtail. A complete single photon detection system needs to comprise the modules, however, the modules of the existing single photon detection system are respectively arranged independently, and the size is large.

SUMMERY OF THE UTILITY MODEL

In order to overcome the above-mentioned defect of prior art, the embodiment of the utility model provides a technical problem that will solve provides a single photon detection system, and a plurality of modules wherein are assembled in a casing, each module links up compactness, system is small, remove convenient and the radiating effect is better.

The embodiment of the utility model provides a concrete technical scheme is:

a single photon detection system comprises an avalanche photodiode, a refrigeration and heat preservation module, a fiber coiling module, a fan, a radiator and a shell cover; the single photon detection system has a front side, a back side, a left side and a right side which can be referred to; the fiber coiling module is arranged on the front side, and the refrigeration and heat preservation module is arranged on the rear side; the avalanche photodiode is arranged in the refrigeration and heat preservation module, the refrigeration and heat preservation module is provided with an optical fiber through hole, and the fiber coiling module is close to the optical fiber through hole; the radiator is arranged below the refrigeration and heat preservation module, the fan is arranged below the fiber coiling module, and an air outlet of the fan faces the radiator; and the shell cover covers the refrigeration and heat preservation module, the fiber coiling module, the fan and the radiator.

Preferably, the single-photon detection system further comprises a flange, wherein the flange is arranged on one side of the fiber coiling module and is arranged on the left side or the right side of the single-photon detection system.

Preferably, the single photon detection system further comprises fixed blocks, and the fixed blocks are arranged on the left side and the right side of the single photon detection system.

Preferably, the housing cover is in an inverted "U" shape, and the housing cover covers the top, left side, and right side of the single photon detection system.

Preferably, still include the fixed frame of fan, fan clamp plate and fan control panel, the fan control panel set up in the fixed frame top of fan, the fixed frame of fan with the combination of fan clamp plate is fixed the fan.

Preferably, the fan fixing frame is provided with a plurality of fan air outlets, the plurality of fans correspond to the plurality of fan air outlets, and the plurality of fans are transversely arranged in the fan fixing frame.

Preferably, it further comprises a first panel disposed at the frontmost side of said single photon detection system and a second panel disposed at the rearmost side of said single photon detection system.

Preferably, the refrigeration and heat preservation module further comprises an electrical interface which penetrates through the shell of the refrigeration and heat preservation module and the second panel.

Preferably, the first panel, the fan pressing plate and the fan control plate are arranged in sequence on the front side of the single photon detection system.

Preferably, the modules or the components of the single photon detection system are fixed by screws.

According to the scheme, the single photon detection system is provided, wherein the radiator is arranged below the refrigeration and heat preservation module, the fan is arranged below the disc fiber module, the disc fiber module is close to the refrigeration and heat preservation module, the shell cover covers the modules, the modules are connected compactly, the modules are assembled in the shell, and the system is small in size and convenient to move. In addition, the fan control board is arranged, and according to the heat dissipation requirements of different degrees, the fan control board can control the rotating speed of the fan, so that the air quantity supplied by the fan is controlled, and the device has a good heat dissipation effect; the air outlet of the fan faces the radiator, and a plurality of fans can be arranged according to the size of the radiator, so that a good radiating effect is further guaranteed.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and the accompanying drawings, which specify the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the present invention are not so limited in scope. The embodiments of the invention include many variations, modifications and equivalents within the spirit and scope of the appended claims. Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for helping the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. The skilled person in the art can, under the teaching of the present invention, choose various possible shapes and proportional dimensions to implement the invention according to the specific situation.

FIG. 1 is a schematic perspective view of a single photon detection system of the present application without the inclusion of a top cover;

FIG. 2 is a schematic front view of a single photon detection system of the present application without the top cover;

FIG. 3 is a schematic bottom view of a single photon detection system of the present application;

FIG. 4 is a schematic side view of a single photon detection system of the present application without the inclusion of a top cover;

FIG. 5 is a schematic perspective view of a single photon detection system top cover according to the present application;

FIG. 6 is a schematic cross-sectional view of a single photon detection system of the present application at a fan;

figure 7 is a schematic perspective view of a fan of the single photon detection system of the present application.

Detailed Description

The details of the present invention can be more clearly understood with reference to the accompanying drawings and the description of the embodiments of the present invention. However, the specific embodiments of the present invention described herein are for the purpose of explanation only, and should not be construed as limiting the invention in any way. Given the teachings of the present invention, the skilled person can conceive of any possible variants based on the invention, which should all be considered as belonging to the scope of the invention. It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, mechanical or electrical connections, communications between two elements, direct connections, indirect connections through intermediaries, and the like. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The application provides a single photon detection system, fig. 1 is a schematic view of a three-dimensional structure of a single photon detection system without an upper cover, fig. 2 is a schematic view of a front-view structure of a single photon detection system without an upper cover, fig. 3 is a schematic view of a bottom-view structure of a single photon detection system, fig. 5 is a schematic view of a three-dimensional structure of an upper cover of a single photon detection system, and fig. 6 is a schematic view of a cross-sectional structure of a single photon detection system at a fan. Referring to fig. 1 to 3 and 5 to 6, a single photon detection system includes an avalanche photodiode, a refrigeration and insulation module 1, a fiber winding module 2, a fan 41, a heat sink 5, and a housing cover 8.

An avalanche photodiode refers to a photosensitive element used in optical communication, which can amplify a photoelectric signal using an avalanche multiplication effect of carriers to improve detection sensitivity.

The refrigeration and heat preservation module 1 is a sealed cavity comprising a multistage semiconductor refrigerator, a photodiode fixing frame, heat insulation fillers, a metal heat preservation shell and a metal heat preservation shell cover. Preferably, the multistage semiconductor refrigerator is a 4-stage refrigeration semiconductor refrigeration chip; the heat insulation filler is one or a combination of a plurality of heat insulation materials such as foam beads, aerogel, heat insulation cotton, vacuum heat insulation plates and the like; the metal materials of the metal heat-insulation shell and the metal heat-insulation shell cover are all metal aluminum or aluminum alloy, and a sealing ring is arranged between the metal heat-insulation shell cover and the metal heat-insulation shell and fixedly connected by screws; the photodiode fixing frame is used for fixing the avalanche photodiode, is made of metal, is of a clamping structure, is directly attached to the cold surface of the multistage semiconductor refrigerator, and is fixed with the multistage semiconductor refrigerator through screws; the heat insulation filler plays a role in heat insulation and heat preservation, can reduce heat exchange between the temperature in the sealed cavity and the external environment temperature of the cavity, and fills the residual space of the sealed cavity formed by the metal heat preservation shell cover and the metal heat preservation shell body. The avalanche photodiode is arranged in the refrigeration and heat preservation module 1 and is fixed on the photodiode fixing frame, the refrigeration and heat preservation module 1 further comprises a signal processing circuit, the signal processing circuit is electrically connected with the avalanche photodiode, and the connection combination of the avalanche photodiode and the signal processing circuit can realize the functions of converting optical signals into electric signals and processing weak signals.

The optical fiber pigtail that the fine module 2 of dish is used for acceping avalanche photodiode, it includes supporting part and portion of acceping, the portion of acceping sets up on the supporting part, the shape of supporting part is slice square or oval, can set up a plurality of portions of acceping on the supporting part, the quantity of specific portion of acceping can be selected and adjusted according to the quantity of refrigeration heat preservation module 1, this application does not do the restriction here, wherein the portion of acceping comprises four ply-yarn cards again, range position between every two adjacent ply-yarn cards makes the crooked radius of optic fibre equal to or be greater than the crooked minimum radius of curvature of optic fibre when normally working, the ply-yarn drill includes spacing body, spacing groove that link up has in the spacing body, be provided with the long and narrow gap with spacing groove intercommunication on spacing body, optic fibre accessible long and narrow gap is.

Referring to FIGS. 1-3, the single photon detection system has a front side, a back side, a left side and a right side which can be referenced; the fiber coiling module 2 is arranged on the front side, and the refrigeration and heat preservation module 1 is arranged on the rear side. The refrigeration and heat preservation module 1 is provided with an optical fiber through hole, the fiber coiling module 2 is close to the optical fiber through hole, preferably, as shown in fig. 2, the fiber coiling module 2 and the refrigeration and heat preservation module 1 are transversely arranged in tandem and are contacted with each other, the volume of the single photon detection system can be reduced, and the connection among the modules is more compact.

The fan 41 is used for supplying air to the heat sink 5 to accelerate heat dissipation, and may be a dc or ac fan, which is selected according to cost or volume, and the application is not limited in this respect. The radiator 5 is used for radiating the refrigeration and heat preservation module 1, the multistage semiconductor refrigerator is provided with a cold surface and a hot surface which are opposite, and the heat of the hot surface needs to be radiated through the radiator 5; the radiator 5 comprises a heat conducting plate and radiating fins, wherein the heat conducting plate and the radiating fins are made of metal materials and are integrally formed, the heat conducting plate of the radiator 5 is tightly attached to the hot surface of the multistage semiconductor refrigerator, and the heat conducting plate transfers the heat of the hot surface to the radiating fins of the radiator 5.

Referring to fig. 1 to 3, the heat sink 5 is disposed below the refrigeration and heat preservation module 1, the fan 41 is disposed below the fiber coiling module 2, an air outlet of the fan 41 faces the heat sink 5, and specifically, an airflow direction between the heat dissipation fins in the heat sink 5 is consistent with an air outlet of the fan 41, so as to ensure smoothness of overall heat dissipation.

The single photon detection system also comprises a cover 8, and the cover 8 is used as a sealing cover, namely the cover covers the refrigeration and heat preservation module 1, the fiber coiling module 2, the fan 41 and the radiator 5. Specifically, referring to fig. 5, the case cover 8 is a metal case cover, and is in an inverted "U" shape, and is used for covering the top, left side, and right side of the single photon detection system; the side edges of two sides of the inverted U-shaped shell cover 8 are fixed on the left side and the right side of the single photon detection system, and the top of the inverted U-shaped shell cover is used for covering the refrigeration and heat preservation module 1 and the fiber coiling module 2.

The module of the single photon detection system is fixed with the module or the component of the single photon detection system through screws, the single photon detection system can be connected in a bonding mode, a riveting mode or a clamping mode, the screws are preferably selected for connection, the screws are convenient to detach, the sealing performance is good, the single photon detection system is firm to fix, and even if the single photon detection system shakes, the single photon detection system can keep good stability.

Through the embodiment, the modules of the single photon detection system can be assembled in one shell, the modules can be connected compactly, the volume of the system can be greatly reduced, and the system can be conveniently moved and maintained after the modules are assembled and integrated.

Fig. 4 is a schematic side view of a single photon detection system without an upper cover according to the present application, and referring to fig. 1 to 4, the single photon detection system may further include a flange 3. The flange is a part for connecting the shafts and is used for connecting pipe ends; there are also flanges on the inlet and outlet of the device for connection between two devices. The flange 3 is arranged on one side of the disc fiber module 2 and on the left side or the right side of the single photon detection system, specifically, the flange 3 is used for fixedly connecting two optical fiber connectors, the tail end or the head end of the optical fiber is usually provided with an optical fiber connector, the optical fiber connector connected to the tail end of the optical fiber of the single photon detection system is fixed on the flange port on the outer side of the system, the optical fiber connector connected to the head end of the optical fiber of the disc fiber module 2 is fixed on the flange port on the inner side of the system, the single photon detection system can comprise a plurality of flanges 3, and the number of the flanges 3 is consistent with the number of the avalanche. Specifically, an optical fiber accessed to the single photon detection system enters the inner side of the system through a flange 3, passes through the optical fiber coiling and accommodating of the optical fiber coiling module 2, and is finally accessed to an avalanche photodiode in the system.

Referring to fig. 1 to 4, the single photon detection system may further include a fixing block 7, and the fixing block 7 is disposed on the left side and the right side of the single photon detection system, that is, the fixing blocks 7 are disposed on both sides of the system. Specifically, the fixed block 7 is fixed on the left side and the right side of the single photon detection system through screws, the fixed block 7 is further provided with a transverse convex edge, a screw hole is formed in the convex edge, and the screw hole and the screws are matched to fix the single photon detection system in other quantum communication equipment boxes.

Referring to fig. 1 to 5, a flange through hole is formed in one side of the housing cover 8 in an inverted U shape, so that a flange port on the outside of the system can pass through the housing cover 8. Screw holes are formed in two sides of the shell cover 8, and two sides of the shell cover 8 can be fixed to the fixing blocks 7 on two sides of the system in a screw fixing mode.

Fig. 6 is a schematic sectional view of a single photon detection system of the present application at a fan, fig. 7 is a schematic perspective view of the single photon detection system of the present application at the fan, and referring to fig. 1 to 4 and fig. 6 to 7, the single photon detection system may further include a fan fixing frame 42, a fan pressing plate 43, and a fan control plate 44, the fan control plate 44 is disposed above the fan fixing frame 42, and the fan fixing frame 42 and the fan pressing plate 43 are combined to fix the fan 41. Specifically, referring to fig. 7, the fan fixing frame 42 is rotated counterclockwise by 90 degrees in a "U" shape and then is fixedly connected to the fan pressing plate 43 by screws; the fan pressing plate 43 is a metal thin plate, is provided with screw holes, and can be connected with other parts through screws; one side of the fan fixing frame 42 is provided with a fan outlet. As shown in fig. 6 and 7, the elongated fan fixing frame 42 can accommodate a plurality of fans 41 therein, the plurality of fans 41 correspond to the plurality of fan outlets, the plurality of fans 41 are transversely arranged in the fan fixing frame 42, and the number of fans 41 can be adjusted according to the size of the heat sink 5, which is not limited in this application.

Through the above embodiment, according to the heat dissipation requirements of different degrees, the fan control board 44 can control the rotation speed of the fan 41, and further control the air volume supplied by the fan 41, so that the system has a good heat dissipation effect; the air outlet of the fan 41 faces the heat sink 5, and a plurality of fans 41 can be arranged according to the size of the heat sink 5, thereby further ensuring that the system has a good heat dissipation effect.

The single photon detection system may further include a first panel 61 and a second panel 62, the first panel 61 being disposed at a frontmost side of the single photon detection system, the second panel 62 being disposed at a rearmost side of the single photon detection system. Referring to fig. 1, 2 and 4, the first panel 61 and the second panel 62 are both metal panels and are provided with screw holes, and can be fixed to the foremost side and the rearmost side of the single photon detection system by screws, respectively, for clamping and covering the front side and the rear side of the system. As shown in fig. 2, the first panel 61, the fan platen 43, and the fan control board 44 are arranged in this order at a front position of the single photon detection system for the sake of compactness of the system.

Referring to fig. 1 and 2, the single photon detection system further includes an electrical interface 12, where the electrical interface 12 is electrically connected to the signal processing circuit in the refrigeration and heat preservation module 1; for the convenience of signal transmission between different devices, the electrical interface 12 passes through the housing of the refrigeration and insulation module 1 and the second panel 62 and extends to the outside of the single photon detection system.

Referring to fig. 1 to 7, the modules or the parts of the single photon detection system are fixed by screws. The single photon detection system provided by the application has the advantages that the modules are connected compactly, and the system volume is small, so that the single photon detection system can adopt a plurality of sets of the refrigeration and heat preservation modules 1 simultaneously as required to realize the purpose of simultaneously detecting a plurality of avalanche photodiodes. In a feasible implementation manner, referring to fig. 1 to 7, a single photon detection system includes four refrigeration and insulation modules 1, the refrigeration and insulation modules 1 are placed side by side in the single photon detection system, and correspondingly include four avalanche photodiodes and four flanges 3, six fans 41 are arranged according to the size of a heat sink 5, and the four avalanche photodiodes in the system can work simultaneously and can also be divided into different detection modes.

The present application has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to limit the application. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the presently disclosed embodiments and implementations thereof without departing from the spirit and scope of the present disclosure, and these fall within the scope of the present disclosure. The protection scope of this application is subject to the appended claims.

Claims (10)

1. A single photon detection system is characterized by comprising an avalanche photodiode, a refrigeration and heat preservation module (1), a fiber coiling module (2), a fan (41), a radiator (5) and a shell cover (8);

the single photon detection system has a front side, a back side, a left side and a right side which can be referred to;

the fiber coiling module (2) is arranged on the front side, and the refrigeration and heat preservation module (1) is arranged on the rear side;

the avalanche photodiode is arranged in the refrigeration heat-preservation module (1), the refrigeration heat-preservation module (1) is provided with an optical fiber through hole, and the fiber coiling module (2) is close to the optical fiber through hole;

the radiator (5) is arranged below the refrigeration and heat preservation module (1), the fan (41) is arranged below the fiber coiling module (2), and an air outlet of the fan (41) faces the radiator (5);

and the shell cover (8) covers the refrigeration and heat preservation module (1), the fiber coiling module (2), the fan (41) and the radiator (5).

2. The single photon detection system according to claim 1, further comprising a flange (3), said flange (3) being arranged on one side of said disk module (2) and on the left or right side of said single photon detection system.

3. The single photon detection system according to claim 1 further comprising fixed blocks (7), said fixed blocks (7) being provided on both the left and right sides of said single photon detection system.

4. The single photon detection system of claim 1, characterized in that said housing cover (8) is in the shape of an inverted "U", said housing cover (8) covering the top, left and right sides of said single photon detection system.

5. The single photon detection system according to claim 1, further comprising a fan fixing frame (42), a fan pressing plate (43) and a fan control plate (44), said fan control plate (44) being disposed above said fan fixing frame (42), said fan fixing frame (42) and said fan pressing plate (43) being combined to fix said fan (41).

6. The single photon detection system according to claim 5, characterized in that said fan fixing frame (42) is provided with a plurality of fan outlets, a plurality of said fans (41) corresponding to said plurality of fan outlets, a plurality of said fans (41) being arranged laterally in said fan fixing frame (42).

7. The single photon detection system of claim 5, further comprising a first panel (61) and a second panel (62), said first panel (61) being disposed at a frontmost side of said single photon detection system, said second panel (62) being disposed at a rearmost side of said single photon detection system.

8. The single photon detection system of claim 7, further comprising an electrical interface (12), said electrical interface (12) passing through a housing of said refrigeration and thermal module (1) and said second panel (62).

9. The single photon detection system of claim 7, wherein said first panel (61), fan platen (43) and fan control board (44) are arranged in sequence at a front side of said single photon detection system.

10. The single photon detection system according to any one of the preceding claims 1 to 9, wherein said modules or parts of said single photon detection system are fixed by screws.

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