An integrated single-photon detector assembly

Abstract

The present invention discloses an integrated single-photon detector assembly, comprising a substrate, a temperature control chip and a multifunctional integrated chip. The temperature control chip comprises a TEC chip. The multifunctional integrated chip integrates a narrow pulse processing module, an avalanche signal discrimination module and an avalanche signal coincidence module. The multifunctional integrated chip is placed above the TEC chip. The narrow pulse processing module is connected to the avalanche signal coincidence module, and the avalanche signal coincidence module is connected to the avalanche signal discrimination module. The present invention has the advantages of small circuit space occupation, low production difficulty and cost savings.

Description

Technical Field

[0001] The present invention relates to the field of quantum communication, and more particularly to an integrated single-photon detector assembly. Background Art

[0002] Currently, single photons are widely used as information carriers in quantum communication systems, with single-photon detectors used as photoelectric receiving modules to detect and count single photons. However, the photoelectric conversion and effective signal extraction for counting in single-photon detectors requires complex processing. Signal processing modules are diverse and utilize a large number of printed circuit boards (PCBs). Fan cooling systems are often used to dissipate heat and control the temperature of one or more modules, which inevitably leads to temperature fluctuations. Actual testing has found that temperature fluctuations can lead to signal processing instability in various functional modules. The wiring connections between modules increase circuit impedance, which can easily lead to signal distortion.

[0003] As important signal processing modules, the narrow pulse processing module, avalanche signal discrimination module, and avalanche signal coincidence module in the single-photon detector all use large-area PCB printed circuit boards. The line connections between the modular PCB printed circuit boards are cumbersome, and the quality of signal processing cannot be guaranteed.

[0004] In the existing technology, most functional modules use modular PCB printed circuit boards, which results in the narrow pulse processing module, avalanche signal discrimination module, and avalanche signal compliance module in the single-photon detector being large in size and having high manufacturing costs. Each functional module generally uses an air-cooled heat dissipation system, which cannot centrally dissipate heat and control large temperature fluctuations. As a result, the signals of each functional module are prone to temperature drift during the signal processing process, reducing signal quality. The redundant line connections between the functional modules can easily lead to signal distortion. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the functional modules of the single-photon detector in the prior art mostly use modular PCB printed circuit boards, which results in large volume and high manufacturing cost.

[0006] The present invention solves the above technical problems through the following technical solutions: an integrated single-photon detector assembly, including a substrate, a temperature control chip and a multifunctional integrated chip, the temperature control chip including a TEC chip, the TEC chip being fixed on the substrate, the multifunctional integrated chip being placed above the TEC chip, the multifunctional integrated chip integrating a narrow pulse processing module, an avalanche signal discrimination module and an avalanche signal coincidence module, the narrow pulse processing module being connected to the avalanche signal coincidence module, and the avalanche signal coincidence module being connected to the avalanche signal discrimination module.

[0007] Preferably, the multifunctional integrated chip is integrated by using COB bare chip technology, and the electrical connections among the narrow pulse processing module, the avalanche signal discrimination module and the avalanche signal coincidence module are integrated inside the chip.

[0008] Preferably, the electrical connection between the leads of the multifunctional integrated chip and the substrate is achieved by wire bonding.

[0009] Preferably, the multifunctional integrated chip and its leads are soft-encapsulated on the substrate with sealing glue.

[0010] Preferably, the multifunctional integrated chip is externally connected to an APD device, the gate signal input lead is connected to the input end of the narrow pulse processing module, the output end of the narrow pulse processing module is connected to an input end of the avalanche signal compliance module, and the output end of the narrow pulse processing module is connected to the APD device through a bias gate signal output lead; one input end of the avalanche signal discrimination module is connected to the APD device through an avalanche signal input lead, the other input end of the avalanche signal discrimination module is connected to the discrimination threshold input lead, the output end of the avalanche signal discrimination module is connected to another input end of the avalanche signal compliance module, the output end of the avalanche signal compliance module is connected to the pulse counting signal output lead, the APD device receives a photon signal, and the temperature control chip is in contact with the multifunctional integrated chip.

[0011] Preferably, the temperature control chip also includes a temperature probe and an external control circuit, the temperature probe is fixed on the TEC chip, the external control circuit includes a DC / DC chip, an ARM processor, an A / D converter and a D / A converter, the temperature probe is connected to the A / D converter, the ARM processor, the D / A converter and the DC / DC chip in sequence, and the TEC chip is connected between the temperature probe and the DC / DC chip.

[0012] Preferably, the TEC chip and the temperature probe both include output leads and input leads, the leads of the TEC chip and the leads of the temperature probe are electrically connected to the substrate, and are soft-encapsulated on the substrate with a sealing glue.

[0013] Preferably, the temperature probe is a PT100 resistor.

[0014] Preferably, the TEC chip is located in the middle of the substrate and pressed onto the substrate, the multifunctional integrated chip is located in the middle above the TEC chip and is bonded to the TEC chip by thermally conductive adhesive, the temperature probe is fixed on the TEC chip near the multifunctional integrated chip, the output lead of the multifunctional integrated chip is arranged on the left side of the TEC chip, the input lead of the multifunctional integrated chip is arranged on the right side of the TEC chip, the input lead and output lead of the temperature probe are side by side with the input lead of the TEC chip below the TEC chip, and the output lead of the TEC chip is located above the TEC chip.

[0015] Preferably, the integrated single-photon detector assembly further comprises a heat sink, and the substrate is mounted on the heat sink via a thermal pad or thermal grease.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] (1) The three functions of single-photon detector, narrow pulse processing, avalanche signal discrimination, and avalanche signal compliance, are integrated into a multifunctional integrated chip, which reduces the space occupied by the original circuit, reduces the difficulty of production and manufacturing, and saves costs.

[0018] (2) Based on the temperature control chip, the temperature of the multifunctional integrated chip is centrally controlled to reduce temperature fluctuations, reduce the temperature drift of the signal, and improve the signal quality.

[0019] (3) The wire bonding method is used to achieve electrical connection with other modules, which reduces the complexity of signal control and avoids signal distortion caused by high impedance circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for the description of the invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is an assembly diagram of an integrated single-photon detector assembly disclosed in an embodiment of the present invention;

[0022] Figure 2 This is a working principle diagram of a multifunctional integrated chip of an integrated single-photon detector assembly disclosed in an embodiment of the present invention;

[0023] Figure 3 This is a flowchart of the temperature control chip working process of an integrated single-photon detector assembly disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. However, the protection scope of the present invention is not limited to the following embodiment.

[0025] like Figure 1 As shown, an integrated single-photon detector assembly includes a multifunctional integrated chip 1, a substrate 2 and a temperature control chip 3.

[0026] Combine Figure 2 As shown, the multifunctional integrated chip 1 integrates the narrow pulse processing module, the avalanche signal discrimination module, and the avalanche signal coincidence module into a unified multifunctional bare chip. As an optional solution, the integration method adopts COB bare chip technology. The electrical connections between the three functional modules are integrated within the chip. The input leads of the multifunctional integrated chip 1 include a gate signal input lead, an avalanche signal input lead, and a discrimination threshold input lead. The output leads include a pulse counting signal output lead and a bias gate signal output lead. The electrical connection between the leads of the multifunctional integrated chip 1 and the substrate 2 is achieved by wire bonding.

[0027] Please continue reading Figure 2 The gate signal input lead is connected to the input end of the narrow pulse processing module, the output end of the narrow pulse processing module is connected to an input end of the avalanche signal compliance module, and the compliance gate signal is output to the avalanche signal compliance module. At the same time, the output end of the narrow pulse processing module is connected to the APD device through the bias gate signal output lead, and the bias gate signal is output to the APD device; one input end of the avalanche signal discrimination module is connected to the APD device through the avalanche signal input lead, and the avalanche signal is input. The other input end of the avalanche signal discrimination module is connected to the discrimination threshold input lead, and the discrimination threshold is input. The output end of the avalanche signal discrimination module is connected to the other input end of the avalanche signal compliance module, and the output end of the avalanche signal compliance module is connected to the pulse counting signal output lead, and the pulse counting signal is output. The APD device receives the photon signal, and the temperature control chip 3 is in contact with the multifunctional integrated chip 1. In this embodiment, the APD is an external test object and is not part of the detector assembly.

[0028] Combine Figure 2 ,like Figure 3 As shown, the temperature control chip 3 includes a TEC chip 301 , a temperature probe 302 , a DC / DC chip 303 , an ARM processor 304 , an A / D converter 305 and a D / A converter 306 .

[0029] The TEC chip 301 is pressed and fixed on the substrate 2 , and the leads of the TEC chip 301 are electrically connected to the substrate 2 by bonding.

[0030] The multifunctional integrated chip 1 is placed above the TEC chip 301 , and the temperature probe 302 is fixed on the TEC chip 301 near the multifunctional integrated chip 1 . The temperature probe 302 collects the temperature signal of the TEC chip 301 to collect the temperature value of the multifunctional integrated chip 1 in real time.

[0031] The TEC chip 301, temperature probe 302, A / D converter 305, ARM processor 304, D / A converter 306, and DC / DC chip 303 are connected end to end in sequence. The temperature probe 302 collects the temperature signal of the TEC chip 301, converts the real-time temperature of the multifunctional integrated chip 1 into a voltage signal, and transmits it to the A / D converter 305. The signal converted by the A / D converter 305 is transmitted to the ARM processor 304. The ARM processor 304 reads the current temperature and compares it with the required normal temperature data pre-stored in the processor. Based on the temperature feedback algorithm, a set of D / A codes is output. The D / A codes are converted by the D / A converter 306 and transmitted to the DC / DC chip 303 to control the output voltage of the DC / DC chip 303, thereby controlling the temperature of the TEC chip 301. This cycle is repeated to achieve normal temperature control of the multifunctional integrated chip 1.

[0032] Taking the 40MHz gate signal as an example, the signal processing process of the multifunctional integrated chip 1 is as follows: the narrow pulse processing module narrows the pulse width of the 40MHz (25ns) gate signal to generate a bias gate signal and a coincidence gate signal with a pulse width of 1.6ns, which are sent to the bias voltage circuit and the avalanche signal coincidence module of the APD device respectively. The bias gate signal acts on the bias voltage circuit of the APD device to control the avalanche and avalanche suppression of the APD device. The coincidence gate signal cooperates with the avalanche signal coincidence module to extract the effective signal from the avalanche differential signal for counting; The avalanche signal discrimination module amplifies the weak avalanche signal generated by the APD device through an amplifier circuit. Using a given discrimination threshold, it filters out avalanche signals caused by thermal noise, afterpulses, and simultaneous multi-photon arrivals, extracting the single-photon avalanche signal. The avalanche signal coincidence module uses a logic AND gate to perform a logical AND operation on the differential signal output by the avalanche signal discrimination module and the coincidence gate signal output by the narrow pulse processing module. This process extracts the avalanche signal from the differential signal output by the avalanche signal discrimination module and outputs a pulse count signal. Temperature control chip 3 provides constant temperature control for multifunctional integrated chip 1.

[0033] As a preferred solution, the multifunctional integrated chip 1, TEC chip 301, temperature probe 302 and leads are all soft-encapsulated on the substrate 2 with sealing glue to prevent contamination and human damage, and to prevent circuit interference problems between the multifunctional integrated chip 1 and the TEC chip 301.

[0034] As a preferred solution, the temperature probe 302 is a PT100 resistor.

[0035] As a preferred solution, the TEC chip 301 is located in the middle position of the substrate 2 and pressed onto the substrate 2. The multifunctional integrated chip 1 is located in the middle position above the TEC chip 301 and is bonded to the TEC chip 301 through thermal conductive adhesive. The temperature probe 302 is fixed on the TEC chip 301 near the multifunctional integrated chip 1. The multifunctional integrated chip 1, TEC chip 301 and temperature probe 302 all include output leads (not marked in the figure) and input leads (not marked in the figure). The output leads of the multifunctional integrated chip 1 are arranged on the left side of the TEC chip 301, and the input leads of the multifunctional integrated chip 1 are arranged on the right side of the TEC chip 301. The input leads and output leads of the temperature probe 302 are located side by side with the input leads of the TEC chip 301 below the TEC chip 301, and the output leads of the TEC chip 301 are located above the TEC chip 301.

[0036] As a preferred solution, the leads of the multifunctional integrated chip 1 , the leads of the TEC chip 301 , and the leads of the temperature probe 302 are all electrically connected to the substrate 2 by wire bonding.

[0037] As a preferred solution, the TEC chip 301 and the substrate 2 are both rectangular.

[0038] As a preferred solution, the single-photon detector assembly further includes a heat sink 4 , and the substrate 2 is mounted on the heat sink 4 via a thermal pad or thermal grease, and heat is dissipated through the heat sink 4 .

[0039] The working principle of the present invention is: using the COB process to integrate the three functions of gate signal narrow pulse processing, avalanche signal discrimination, and avalanche signal compliance in the single-photon detector into a single multifunctional bare chip, miniaturizing the original circuit integration, and using the temperature control chip 3 to centrally control the temperature of the bare chip, so that the output signal quality of the bare chip is higher, and the influence of impedance on signal distortion is reduced, which helps to improve the counting efficiency of the single-photon detector.

[0040] Through the above technical scheme, the present invention provides an integrated single-photon detector component based on the COB process, and the PCB printed circuit board of the narrow pulse processing module, avalanche signal discrimination module, and avalanche signal compliance module in the single-photon detector is processed as an integrated bare chip, and a temperature control chip 3 is designed to match the integrated bare chip. It has the advantages of small circuit space, low production difficulty, and cost saving. Based on the temperature control chip 3, the functional integrated chip is centrally temperature-controlled, temperature fluctuations are reduced, the temperature drift of the signal is reduced, and the signal quality is improved. The wire bonding method is used to achieve electrical connection with other modules, which reduces the complexity of signal control and avoids signal distortion caused by high-impedance circuits.

[0041] 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 scope of protection of the present invention.

Claims

1. An integrated single-photon detector assembly, comprising a substrate, characterized in that: It also includes a temperature control chip and a multifunctional integrated chip, the temperature control chip includes a TEC chip, the TEC chip is fixed on a substrate, the multifunctional integrated chip is placed above the TEC chip, the temperature control chip is in contact with the multifunctional integrated chip, the temperature control chip collects the temperature value of the multifunctional integrated chip to achieve normal temperature control, the multifunctional integrated chip integrates a narrow pulse processing module, an avalanche signal discrimination module and an avalanche signal compliance module, the narrow pulse processing module is connected to the avalanche signal compliance module, and the avalanche signal compliance module is connected to the avalanche signal discrimination module.

2. The integrated single-photon detector assembly according to claim 1, characterized in that: The integration method of the multifunctional integrated chip adopts COB bare chip technology, and the electrical connections between the narrow pulse processing module, the avalanche signal identification module and the avalanche signal compliance module are integrated inside the chip.

3. The integrated single-photon detector assembly according to claim 1, characterized in that: The electrical connection between the leads of the multifunctional integrated chip and the substrate is achieved by wire bonding.

4. The integrated single-photon detector assembly according to claim 1, characterized in that: The multifunctional integrated chip and its leads are soft-encapsulated on the substrate with sealing glue.

5. The integrated single-photon detector assembly according to claim 1, characterized in that: The multifunctional integrated chip is externally connected to an APD device, a gate signal input lead is connected to the input end of a narrow pulse processing module, an output end of the narrow pulse processing module is connected to an input end of an avalanche signal coincidence module, and an output end of the narrow pulse processing module is connected to the APD device via a bias gate signal output lead; an input end of an avalanche signal discrimination module is connected to the APD device via an avalanche signal input lead, another input end of the avalanche signal discrimination module is connected to a discrimination threshold input lead, an output end of the avalanche signal discrimination module is connected to another input end of an avalanche signal coincidence module, an output end of the avalanche signal coincidence module is connected to a pulse counting signal output lead, and the APD device receives a photon signal.

6. The integrated single-photon detector assembly according to claim 1, characterized in that: The temperature control chip also includes a temperature probe and an external control circuit. The temperature probe is fixed on the TEC chip. The external control circuit includes a DC / DC chip, an ARM processor, an A / D converter and a D / A converter. The temperature probe is connected to the A / D converter, the ARM processor, the D / A converter and the DC / DC chip in sequence. The TEC chip is connected between the temperature probe and the DC / DC chip.

7. The integrated single-photon detector assembly according to claim 6, characterized in that: The TEC chip and the temperature probe both include output leads and input leads. The leads of the TEC chip and the temperature probe are both electrically connected to the substrate and are soft-encapsulated on the substrate with a sealing glue.

8. The integrated single-photon detector assembly according to claim 6, characterized in that: The temperature probe is a PT100 resistor.

9. The integrated single-photon detector assembly according to claim 6, characterized in that: The TEC chip is located in the middle of the substrate and pressed onto the substrate. The multifunctional integrated chip is located in the middle above the TEC chip and bonded to the TEC chip via thermally conductive adhesive. The temperature probe is fixed on the TEC chip near the multifunctional integrated chip. The output lead of the multifunctional integrated chip is arranged on the left side of the TEC chip, and the input lead of the multifunctional integrated chip is arranged on the right side of the TEC chip. The input lead and output lead of the temperature probe are located side by side with the input lead of the TEC chip below the TEC chip, and the output lead of the TEC chip is located above the TEC chip.

10. The integrated single-photon detector assembly according to any one of claims 1 to 9, characterized in that: A heat sink is also included, and the substrate is mounted on the heat sink via a thermal pad or thermal grease.

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