High-speed InGaAs optical fiber coupling detection circuit and multi-channel high-speed InGaAs optical fiber coupling detector

Abstract

The utility model discloses a high-speed InGaAs optical fiber coupling detection circuit and a multichannel high-speed InGaAs optical fiber coupling detector, the high-speed InGaAs optical fiber coupling detection circuit comprises a photodiode PD and a trans-impedance amplifier, the trans-impedance amplifier comprises a first-stage operational amplifier circuit and a second-stage operational amplifier circuit, the photodiode PD is used for converting an optical signal into a current signal and outputting the current signal, and the second-stage operational amplifier circuit is used for outputting the current signal. The photodiode PD is connected with the first-stage operational amplifier circuit, the first-stage operational amplifier circuit is used for amplifying current signals output by the photodiode PD into equal-proportion voltage signals and then outputting the voltage signals, and the second-stage operational amplifier circuit is connected with the first-stage operational amplifier circuit. And the second-stage operational amplifier circuit is used for carrying out in-phase proportional amplification on the voltage signal output by the first-stage operational amplifier circuit and then outputting the voltage signal. The multichannel high-speed InGaAs optical fiber coupling detector comprises a plurality of high-speed InGaAs optical fiber coupling detection circuits, a power interface and a connecting piece with an SCSI (Small Computer System Interface).

Description

Technical Field

[0001] The utility model relates to the technical field of communications, in particular to a high-speed InGaAs optical fiber coupled detection circuit and a multi-channel high-speed InGaAs optical fiber coupled detector. Background Art

[0002] A fiber-coupled detector is a high-speed optical detector that can convert optical signals into electrical signals and is often used in conjunction with optical fiber technology to achieve efficient transmission and detection of optical signals.

[0003] Fiber-coupled detectors operate based on the photoelectric effect, whereby light strikes a detector's photosensitive element, generating a change in current or voltage. These detectors typically incorporate a high-performance photodiode capable of detecting light signals within a specific wavelength range and converting them into electrical signals. The detector's fiber-optic interface allows direct coupling of optical signals into the detector, minimizing signal loss and interference.

[0004] Fiber-coupled detectors are widely used in weak light signal detection, fast laser pulse detection, RF and pulse waveform extraction from laser sources, heterodyne laser beat frequency signal detection, and fiber-optic sensing. They are widely used in optical communication networks, fiber-optic local area networks, fiber-optic sensing, and fiber-optic cable television systems.

[0005] The fiber-coupled detector in the prior art has the problem that the gain when converting an optical signal into an electrical signal is too small and can only realize the conversion of a single optical signal. Utility Model Content

[0006] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a high-speed InGaAs fiber-coupled detection circuit that can effectively increase the gain when converting optical signals into electrical signals.

[0007] In addition, the utility model also provides a multi-channel high-speed InGaAs fiber-coupled detector to simultaneously realize the conversion of multiple channel optical signals.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] A high-speed InGaAs fiber-coupled detection circuit includes a photodiode PD and a transimpedance amplifier. The transimpedance amplifier includes a first-stage operational amplifier circuit and a second-stage operational amplifier circuit. The photodiode PD is used to convert an optical signal into a current signal for output. The photodiode PD is connected to the first-stage operational amplifier circuit. The first-stage operational amplifier circuit is used to amplify the current signal output by the photodiode PD into a proportional voltage signal and then output it. The second-stage operational amplifier circuit is connected to the first-stage operational amplifier circuit. The second-stage operational amplifier circuit is used to amplify the voltage signal output by the first-stage operational amplifier circuit in the same phase and then output it.

[0010] The working principle of this scheme is as follows: when the circuit of this scheme is working, the photodiode PD is a photodetector. Its working principle is that when the PN junction in the semiconductor is irradiated by light and the energy of the incident light is higher than the band gap energy of the photodiode, electrons and holes will be generated. Driven by the internal electric field, the electrons and holes move in opposite directions respectively, forming a photocurrent. The photodiode PD is used to convert the light signal into a current signal. The first-stage operational amplifier circuit is used to realize transimpedance amplification. The current signal generated by the photodiode PD passes through the first-stage operational amplifier circuit and is amplified into a proportional voltage signal for output. The second-stage operational amplifier circuit is a non-inverting proportional amplifier circuit. The voltage signal output by the first-stage operational amplifier circuit passes through the second-stage operational amplifier circuit and is amplified in phase to a suitable signal amplitude before output. Therefore, this circuit can be used to convert a weak current signal into a voltage signal with a larger signal amplitude, effectively increasing the gain when the light signal is converted into an electrical signal.

[0011] Preferably, the first-stage operational amplifier circuit includes an operational amplifier A1, a feedback resistor R1 and a feedback capacitor C1, the non-inverting input terminal of the operational amplifier A1 is grounded through an input resistor R3, the anode of the photodiode PD is connected to the non-inverting input terminal of the operational amplifier A1, and the cathode of the photodiode PD is connected to the inverting input terminal of the operational amplifier A1, the feedback resistor R1 and the feedback capacitor C1 are connected in parallel, and one end of the parallel connection of the feedback resistor R1 and the feedback capacitor C1 is connected to the inverting input terminal of the operational amplifier A1, and the other end is connected to the output terminal of the operational amplifier A1, the ground terminal of the operational amplifier A1 is grounded, the power supply terminal of the operational amplifier A1 is connected to the +12V power supply, and the power supply terminal of the operational amplifier A1 is also grounded through a capacitor C2.

[0012] Preferably, the first stage operational amplifier circuit outputs a voltage V out The calculation formula is:

[0013] V out =i1×R1

[0014] Wherein: i1 is the input current of the operational amplifier A1.

[0015] Preferably, the second-stage op amp circuit includes an operational amplifier A2, an output resistor R2, a resistor R5 and a resistor R6, the non-inverting input terminal of the operational amplifier A2 is connected to the output terminal of the operational amplifier A1 through the input resistor R7, the inverting input terminal of the operational amplifier A2 is grounded through the resistor R6, the inverting input terminal of the operational amplifier A2 is also connected to the output terminal of the operational amplifier A2 through the resistor R5, and the output terminal of the operational amplifier A2 is connected to the output resistor R2, the ground terminal of the operational amplifier A2 is grounded, the power supply terminal of the operational amplifier A2 is connected to the +12V power supply, and the power supply terminal of the operational amplifier A2 is also grounded through the capacitor C2.

[0016] Preferably, the voltage amplification factor of the second-stage operational amplifier circuit is A u The calculation formula is:

[0017]

[0018] Preferably, the resistance of the resistor R7 is the parallel resistance of the resistor R5 and the resistor R6.

[0019] A multi-channel high-speed InGaAs fiber-coupled detection detector comprises a plurality of the aforementioned high-speed InGaAs fiber-coupled detection circuits, a power interface, and a connector having a SCSI interface. The power supply end of each high-speed InGaAs fiber-coupled detection circuit is connected to the power interface so that power is supplied to each high-speed InGaAs fiber-coupled detection circuit via the power interface. The output end of each high-speed InGaAs fiber-coupled detection circuit is respectively connected to different pins of the connector so that the voltage signal of each high-speed InGaAs fiber-coupled detection circuit is output via the connector.

[0020] In this way, the power supply ends of multiple high-speed InGaAs fiber-coupled detection circuits are connected to the power interface, and then the output ends of each high-speed InGaAs fiber-coupled detection circuit are connected to different pins of the connector, thereby achieving simultaneous output of multi-channel signals.

[0021] Preferably, it includes 8 high-speed InGaAs fiber-coupled detection circuits and DB68 connectors, and the output ends of the 8 high-speed InGaAs fiber-coupled detection circuits are PD1_AMP_OUT, PD2_AMP_OUT, PD3_AMP_OUT, PD4_AMP_OUT, PD5_AMP_OUT, PD6_AMP_OUT, PD7_AMP_OUT and PD8_AMP_OUT, respectively, and the output signals PD1_AMP_OUT to PD8_AMP_OUT are respectively connected to the corresponding pins of the DB68 connector in single-ended mode.

[0022] Preferably, it includes 16 high-speed InGaAs fiber-coupled detection circuits and DB68 connectors, and the output ends of the 16 high-speed InGaAs fiber-coupled detection circuits are PD1_AMP_OUT, PD2_AMP_OUT, PD3_AMP_OUT, PD4_AMP_OUT, PD5_AMP_OUT, PD6_AMP_OUT, PD7_AMP_OUT, D8_AMP_OUT, PD9_AMP_OUT, PD10_AMP_OUT, PD11_AMP_OUT, PD12_AMP_OUT, PD13_AMP_OUT, P14_AMP_OUT, PD15_AMP_OUT and D16_AMP_OUT, and the output signals PD1_AMP_OUT to PD16_AMP_OUT are respectively connected to the corresponding pins of the DB68 connector in single-ended mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the circuit principle diagram of the utility model high-speed InGaAs fiber-coupled detection circuit;

[0024] Figure 2 This is a graph showing the output current of the photodiode PD in the high-speed InGaAs fiber-coupled detection circuit of the present invention as a function of the input optical power;

[0025] Figure 3 This is a graph showing the output power of the high-speed InGaAs fiber-coupled detection circuit of the utility model as a function of input optical power;

[0026] Figure 4 This is a circuit layout diagram of the 8-channel high-speed InGaAs fiber-coupled detector in Example 1;

[0027] Figure 5 This is a circuit schematic diagram of an 8-channel high-speed InGaAs fiber-coupled detector in Example 1;

[0028] Figure 6This is the circuit layout diagram of the 16-channel high-speed InGaAs fiber-coupled detector in Example 2;

[0029] Figure 7 This is a circuit schematic diagram of a 16-channel high-speed InGaAs fiber-coupled detector in Example 2;

[0030] Figure 8 This is a graph showing the output voltages of the 16 channels of the 16-channel high-speed InGaAs fiber-coupled detector in Example 2 when the input optical power is 1.012 uW. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the utility model belongs.

[0032] The words "first", "second" and similar words used in the specification and claims of the utility model patent application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular form of "a", "an" or "the" and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" cover the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] As attached Figure 1As shown, this solution provides a high-speed InGaAs fiber-coupled detection circuit, including a photodiode PD and a transimpedance amplifier. In this specific embodiment, the photodiode can be a PIN photodiode. The PIN photodiode is a basic photodetector. Its working principle is that when the PN junction in the semiconductor is irradiated by light and the incident light energy is higher than the band gap energy of the photodiode, electrons and holes are generated. Driven by the internal electric field, the electrons and holes move in opposite directions, forming a photocurrent. Figure 2 In optical fiber communication systems, InGaAs PIN photodiodes, as photodetectors, can efficiently convert optical signals into electrical signals and are one of the core components of optical receivers. PIN photodiodes have advantages such as fast response, high linearity, and high sensitivity, but their gain is relatively small and requires external circuitry for amplification.

[0034] The essence of a transimpedance amplifier is an amplifier that uses voltage parallel negative feedback. Its function is to convert a small input current into a proportional output voltage. The gain of the transimpedance amplifier can be changed by adjusting the resistance value of the feedback resistor Rf. In actual circuits, there will be some input and stray capacitance values ​​on the input pins of the amplifier, which can cause self-oscillation and output drift, thereby making the entire amplifier circuit unstable. This problem can usually be overcome by connecting a feedback capacitor in parallel, and the frequency response is controlled by the feedback capacitor. In this specific embodiment, the transimpedance amplifier includes a first-stage operational amplifier circuit and a second-stage operational amplifier circuit. The photodiode PD is used to convert the optical signal into a current signal output. The photodiode PD is connected to the first-stage operational amplifier circuit. The first-stage operational amplifier circuit is used to amplify the current signal output by the photodiode PD into a proportional voltage signal and then output it. The second-stage operational amplifier circuit is connected to the first-stage operational amplifier circuit. The second-stage operational amplifier circuit is used to amplify the voltage signal output by the first-stage operational amplifier circuit in the same phase and then output it.

[0035] Specifically, the first-stage op amp circuit implements transimpedance amplification using voltage-parallel negative feedback. It includes an op amp A1, a feedback resistor R1, and a feedback capacitor C1. Feedback resistor R1 typically ranges from several hundred ohms to several tens of kiloohms. Feedback capacitor C1 is a phase compensation capacitor that prevents self-oscillation of the op amp and suppresses high-frequency noise. The non-inverting input of op amp A1 is connected to ground via input resistor R3, which serves as the input resistor of the first-stage op amp circuit and is generally large. The anode of photodiode PD is connected to the non-inverting input of op amp A1, and the cathode of photodiode PD is connected to the inverting input of op amp A1. Feedback resistor R1 and feedback capacitor C1 are connected in parallel, with one end of the parallel connection connected to the inverting input of op amp A1 and the other end connected to the output of op amp A1. The ground terminal of op amp A1 is grounded, and the power supply of op amp A1 is connected to a +12V power supply. The power supply of op amp A1 is also connected to ground via capacitor C2.

[0036] Specifically, the output voltage of the first-stage op amp circuit is V out The calculation formula is:

[0037] V out =i1×R1

[0038] Where: i1 is the input current of operational amplifier A1.

[0039] Specifically, the second-stage op amp circuit is essentially a non-inverting proportional operational circuit, which requires very high input resistance and very low output resistance. It includes operational amplifier A2, output resistor R2, resistors R5, and resistors R6. The non-inverting input of operational amplifier A2 is connected to the output of operational amplifier A1 via input resistor R7. The inverting input of operational amplifier A2 is grounded via resistor R6. The inverting input of operational amplifier A2 is also connected to the output of operational amplifier A2 via resistor R5, and the output of operational amplifier A2 is connected to output resistor R2. The ground terminal of operational amplifier A2 is grounded, and the power supply of operational amplifier A2 is connected to a +12V power supply. The power supply of operational amplifier A2 is also grounded via capacitor C2. Specifically, input resistor R7 can be selected to be in the tens of kilo-ohms, and output resistor R2 can be selected to be in the tens of ohms.

[0040] In this specific embodiment, the voltage amplification factor of the second stage operational amplifier circuit is A u The calculation formula is:

[0041]

[0042] The voltage gain is greater than 1, thereby achieving the purpose of amplifying the output voltage signal of the first-stage op amp circuit. To ensure that the circuit can provide a linear response under different signal amplitudes, the input signal amplitude should be appropriate and the gain should not be too large. Excessive signal input amplitude and gain will cause signal distortion.

[0043] In this specific embodiment, to ensure symmetry, the resistance of the resistor R7 is the parallel resistance of the resistor R5 and the resistor R6.

[0044] The working principle of this scheme is as follows: when the circuit of this scheme is working, the photodiode PD is used to convert the light signal into a current signal. The first-stage operational amplifier circuit is used to realize transimpedance amplification. The current signal generated by the photodiode PD is amplified into a proportional voltage signal after passing through the first-stage operational amplifier circuit and output. The second-stage operational amplifier circuit is a non-inverting proportional amplifier circuit. The voltage signal output by the first-stage operational amplifier circuit is amplified into a suitable signal amplitude after passing through the second-stage operational amplifier circuit. In this way, this circuit can convert a weak current signal into a voltage signal with a larger signal amplitude, as shown in the attached figure. Figure 3 As shown, the gain when the optical signal is converted into an electrical signal is effectively increased.

[0045] In practical applications, there are many transimpedance amplifier (TIA) devices, such as the OPA2810, OPA810, OPA656, and OPA657. This solution uses the OPA2810 as an example. It features unity-gain stable FET inputs (dual-channel) and high-speed performance with a 70MHz gain-bandwidth product and 120MHz small-signal bandwidth. It has a supply voltage range of 4.75V to 27V and an extended operating temperature range of -40°C to +125°C. The appropriate TIA type can be selected based on the input current and the desired voltage gain. To ensure stable performance and low input noise, this solution uses the OPA2810 voltage-feedback operational amplifier. The OPA2810 offers extremely low input bias current, unity-gain stability, and a 120MHz small-signal unity-gain bandwidth. It also provides excellent DC precision and dynamic AC performance with very low quiescent power consumption. Of course, this solution's TIA is not limited to the OP2810; higher-speed TIAs can also be used.

[0046] In addition, this specific embodiment also provides a multi-channel high-speed InGaAs fiber-coupled detection detector, which includes multiple high-speed InGaAs fiber-coupled detection circuits described above, a power interface, and a connector with a SCSI interface. The power supply end of each high-speed InGaAs fiber-coupled detection circuit is connected to the power interface so that power is supplied to each high-speed InGaAs fiber-coupled detection circuit via the power interface. The output end of each high-speed InGaAs fiber-coupled detection circuit is respectively connected to different pins of the connector so that the voltage signal of each high-speed InGaAs fiber-coupled detection circuit is output through the connector.

[0047] In this way, the power supply terminals of multiple high-speed InGaAs fiber-coupled detection circuits are connected to a power interface. To prevent common impedance from introducing power supply noise into the signal loop, this solution utilizes a common-mode inductor filter to filter out some of the power supply noise. Furthermore, digital and analog circuits are used for isolation, minimizing the use of switching power supplies, and utilizing linear power supplies and low-noise amplifiers to suppress the impact of power supply noise. The output terminals of each high-speed InGaAs fiber-coupled detection circuit are then connected to different pins of a connector. The photodiodes (PDs) in the multiple high-speed InGaAs fiber-coupled detection circuits convert optical signals into electrical signals. A transimpedance amplifier, consisting of a first-stage operational amplifier circuit and a second-stage operational amplifier circuit, converts the current signal into a proportional voltage signal. Finally, the signal is output through a connector with a SCSI interface, thereby converting the optical signal into a voltage signal. Appropriate feedback resistors are selected to maximize gain, enabling simultaneous output of multi-channel signals. In practice, this solution outputs the voltage signals from each high-speed InGaAs fiber-coupled detection circuit using a 68-pin DB68 connector with a SCSI interface. The DB68 connector has 68 connectors. Using single-ended mode, the multi-channel output voltage signals are connected to the AI0+ to AI15- pins of the DB68 connector. This allows for the implementation of multi-channel high-speed InGaAs fiber-coupled detectors, such as 4-, 8-, 16-, and 32-channel devices.

[0048] Example 1:

[0049] In this specific embodiment, eight high-speed InGaAs fiber-coupled detection circuits and DB68 connectors are included. To realize an eight-channel high-speed InGaAs fiber-coupled detector, eight circuits and attached components are required. Figure 1 The outputs PD1_AMP_OUT to PD8_AMP_OUT of the same circuit are output in single-ended mode through the DB68 interface and then connected to the data acquisition system. Specifically, the circuit layout of the 8-channel high-speed InGaAs fiber-coupled detector is shown in the attached figure. Figure 4As shown. The output ends of the 8 high-speed InGaAs fiber-coupled detection circuits are PD1_AMP_OUT, PD2_AMP_OUT, PD3_AMP_OUT, PD4_AMP_OUT, PD5_AMP_OUT, PD6_AMP_OUT, PD7_AMP_OUT and PD8_AMP_OUT, and the output signals PD1_AMP_OUT to PD8_AMP_OUT are connected to the corresponding pins of the DB68 connector in single-ended mode. The third pins PD(+) of the 8-channel photodiodes PD1 to PD8 are connected together and finally connected to an analog signal ground port of the DB68. The specific circuit schematic is shown in the attached figure. Figure 5 shown.

[0050] Example 2:

[0051] In this specific embodiment, 16 high-speed InGaAs fiber-coupled detection circuits and DB68 connectors are included. To realize a 16-channel high-speed InGaAs fiber-coupled detector, 16 and the attached Figure 1 The outputs of the same circuit, PD1_AMP_OUT to PD16_AMP_OUT, are output in single-ended mode via a DB68 interface and then connected to a data acquisition system. The circuit layout of the 16-channel high-speed InGaAs fiber-coupled detector is shown in the figure below. Figure 6 As shown in Figure 1, the output terminals of the 16 high-speed InGaAs fiber-coupled detection circuits are PD1_AMP_OUT, PD2_AMP_OUT, PD3_AMP_OUT, PD4_AMP_OUT, PD5_AMP_OUT, PD6_AMP_OUT, PD7_AMP_OUT, D8_AMP_OUT, PD9_AMP_OUT, PD10_AMP_OUT, PD11_AMP_OUT, PD12_AMP_OUT, PD13_AMP_OUT, P14_AMP_OUT, PD15_AMP_OUT, and D16_AMP_OUT. Output signals PD1_AMP_OUT through PD16_AMP_OUT are connected to corresponding pins of the DB68 connector in single-ended mode. The third pins PD(+) of the photodiodes PD1, PD3, PD5, PD7, PD9, PD11, PD13, and PD15 of the odd-numbered channels 1, 3, 5, 7, 9, 11, 13, and 15 are connected together and ultimately to an analog signal ground port of the DB68. Connect the third pins PD(+) of the photodiodes PD2, PD4, PD6, PD8, PD10, PD12, PD14, and PD16 of the even channels 2, 4, 6, 8, 10, 12, 14, and 16 together, and finally connect them to the other analog signal ground port of the DB68. The specific circuit schematic is shown in the attached figure. Figure 7The output voltage of 16 channels under the input optical power of 1.012uW is shown in the attached figure. Figure 8 shown.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Ordinary technicians in this field should understand that those modifications or equivalent replacements of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A high-speed InGaAs fiber-coupled detection circuit, characterized in that: The transimpedance amplifier includes a photodiode PD and a transimpedance amplifier, wherein the transimpedance amplifier includes a first-stage operational amplifier circuit and a second-stage operational amplifier circuit. The photodiode PD is used to convert an optical signal into a current signal for output. The photodiode PD is connected to the first-stage operational amplifier circuit. The first-stage operational amplifier circuit is used to amplify the current signal output by the photodiode PD into a proportional voltage signal and then output it. The second-stage operational amplifier circuit is connected to the first-stage operational amplifier circuit. The second-stage operational amplifier circuit is used to amplify the voltage signal output by the first-stage operational amplifier circuit in the same phase and then output it.

2. The high-speed InGaAs fiber-coupled detection circuit according to claim 1, characterized in that: The first-stage operational amplifier circuit includes an operational amplifier A1, a feedback resistor R1, and a feedback capacitor C1. The non-inverting input terminal of the operational amplifier A1 is grounded through an input resistor R3. The anode of the photodiode PD is connected to the non-inverting input terminal of the operational amplifier A1, and the cathode of the photodiode PD is connected to the inverting input terminal of the operational amplifier A1. The feedback resistor R1 and the feedback capacitor C1 are connected in parallel, and one end of the parallel connection of the feedback resistor R1 and the feedback capacitor C1 is connected to the inverting input terminal of the operational amplifier A1, and the other end is connected to the output terminal of the operational amplifier A1. The ground terminal of the operational amplifier A1 is grounded, and the power supply terminal of the operational amplifier A1 is connected to a +12V power supply. The power supply terminal of the operational amplifier A1 is also grounded through a capacitor C2.

3. The high-speed InGaAs fiber-coupled detection circuit according to claim 2, characterized in that: The first stage operational amplifier circuit outputs a voltage V out The calculation formula is: In out =i1×R1 Wherein: i1 is the input current of the operational amplifier A1.

4. The high-speed InGaAs fiber-coupled detection circuit according to claim 3, characterized in that: The second-stage operational amplifier circuit includes an operational amplifier A2, an output resistor R2, a resistor R5, and a resistor R6. The non-inverting input terminal of the operational amplifier A2 is connected to the output terminal of the operational amplifier A1 through the input resistor R7, the inverting input terminal of the operational amplifier A2 is grounded through the resistor R6, the inverting input terminal of the operational amplifier A2 is also connected to the output terminal of the operational amplifier A2 through the resistor R5, and the output terminal of the operational amplifier A2 is connected to the output resistor R2. The ground terminal of the operational amplifier A2 is grounded, the power supply terminal of the operational amplifier A2 is connected to the +12V power supply, and the power supply terminal of the operational amplifier A2 is also grounded through the capacitor C2.

5. The high-speed InGaAs fiber-coupled detection circuit according to claim 4, characterized in that: The voltage amplification factor of the second-stage operational amplifier circuit is A u The calculation formula is:

6. The high-speed InGaAs fiber-coupled detection circuit according to claim 4, characterized in that: The resistance of the resistor R7 is the parallel resistance of the resistor R5 and the resistor R6.

7. A multi-channel high-speed InGaAs fiber-coupled detector, characterized in that: The invention comprises a plurality of high-speed InGaAs fiber-coupled detection circuits according to claim 1, a power interface, and a connector having a SCSI interface, wherein the power end of each high-speed InGaAs fiber-coupled detection circuit is connected to the power interface so as to supply power to each high-speed InGaAs fiber-coupled detection circuit via the power interface, and the output end of each high-speed InGaAs fiber-coupled detection circuit is respectively connected to different pins of the connector so that the voltage signal of each high-speed InGaAs fiber-coupled detection circuit is output via the connector.

8. The multi-channel high-speed InGaAs fiber-coupled detector according to claim 7, characterized in that: The invention comprises 8 high-speed InGaAs fiber-coupled detection circuits and DB68 connectors. The output ends of the 8 high-speed InGaAs fiber-coupled detection circuits are PD1_AMP_OUT, PD2_AMP_OUT, PD3_AMP_OUT, PD4_AMP_OUT, PD5_AMP_OUT, PD6_AMP_OUT, PD7_AMP_OUT and PD8_AMP_OUT, respectively. The output signals PD1_AMP_OUT to PD8_AMP_OUT are respectively connected to the corresponding pins of the DB68 connector in a single-ended mode.

9. The multi-channel high-speed InGaAs fiber-coupled detector according to claim 7, characterized in that: The invention comprises 16 high-speed InGaAs fiber-coupled detection circuits and a DB68 connector. The output ends of the 16 high-speed InGaAs fiber-coupled detection circuits are PD1_AMP_OUT, PD2_AMP_OUT, PD3_AMP_OUT, PD4_AMP_OUT, PD5_AMP_OUT, PD6_AMP_OUT, PD7_AMP_OUT, D8_AMP_OUT, PD9_AMP_OUT, PD10_AMP_OUT, PD11_AMP_OUT, PD12_AMP_OUT, PD13_AMP_OUT, P14_AMP_OUT, PD15_AMP_OUT and D16_AMP_OUT, and the output signals PD1_AMP_OUT to PD16_AMP_OUT are respectively connected to the corresponding pins of the DB68 connector in a single-ended mode.

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