Resonance balance zero-beat photoelectric detector with notch characteristic and printing device and testing device thereof

Abstract

The invention discloses a resonance balance zero-beat photoelectric detector with a notch characteristic and a printing device and a testing device of the resonance balance zero-beat photoelectric detector, and belongs to the field of photoelectric detectors. The LC series resonance trap circuit is introduced into the resonance type balanced zero-beat detector, noise at the pulse light repetition frequency can be suppressed by adjusting a fine tuning capacitor in the LC series resonance trap circuit, the optimal trap effect is ensured, the saturation power and the signal-to-noise ratio of the photoelectric detector under the pulse light are improved, and the photoelectric detector can be applied to the field of photoelectric detection. The device can be applied to testing of pulse compression light.

Description

Technical Field

[0001] The invention relates to the field of photoelectric detectors, in particular to a resonant balanced zero-beat photoelectric detector with notch characteristics and a printing device and a testing device thereof. Background Art

[0002] In the field of quantum information science, the squeezed state light field has the characteristic of breaking through the quantum noise limit on a certain component. It is a valuable quantum resource and has a wide range of applications in spectral measurement, gravitational wave detection, quantum key distribution and other fields. In recent years, various laboratories have conducted squeezed state measurements and experiments under continuous variable light sources, and applied the squeezed state of continuous variables to quantum teleportation, quantum radar, quantum precision measurement and sensing, etc. Due to the high peak power and special pulse shape, pulse compression and entanglement have attracted more attention. At present, pulse compression has been proven to achieve quantum microscopic imaging by improving the signal-to-noise ratio of the detector.

[0003] In the preparation of pulse compression state and entangled state, in addition to high-quality compressor, high-performance photoelectric detection device is also required. Balanced zero-beat detector is one of the key devices for realizing the detection of compressed state and entangled state. Since the balanced zero-beat detector was proposed, people have been committed to developing a high signal-to-noise ratio and low noise detector. In 2009, the Joint Optical Laboratory of Palacky University and the Institute of Physics developed a balanced zero-beat detector with a bandwidth of 54MHz, and obtained a signal-to-noise ratio of 12dB under a pulsed light power of 12mW. In 2012, the research group of the University of Calgary in Canada developed a 100MHz balanced zero-beat detector, and the signal-to-noise ratio was 13dB under a pulsed light power of 12mW. In 2018, the research group of Professor Li Yongmin of Shanxi University developed a balanced zero-beat detector with a bandwidth of 40MHz, and measured a signal-to-noise ratio of 14.50dB under pulsed light. The above photodetectors all use the traditional transimpedance amplifier structure. Although this structure has the characteristics of low noise, it cannot simultaneously obtain high bandwidth and high slew rate. Resonant detectors are not limited by the gain-bandwidth product, maintain high sensitivity, and obtain higher gain at the resonant frequency. In 2017, the research group of Professor Zheng Yaohui of Shanxi University developed a single-probe resonant photodetector with adjustable resonant frequency for compressed state generation experiments. In 2018, the University of Tokyo in Japan developed a 500MHz resonant balanced zero-beat detector, which achieved a signal-to-noise ratio of 12dB at an optical power of 5mW. In 2022, a 20MHz resonant balanced zero-beat detector was developed. Due to the limitation of the repetition frequency of the pulsed light, only a signal-to-noise ratio of 10.02dB was obtained at an optical power of 3mW. This shows that the saturated optical power and signal-to-noise ratio of the detector under pulsed light need to be improved. Summary of the invention

[0004] The purpose of the present invention is to provide a resonant balanced zero-beat photodetector with notch characteristics and a printing device and a testing device thereof, which can improve the saturated optical power and signal-to-noise ratio of the photodetector under pulse light.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A resonant balanced zero-beat photoelectric detector with a notch characteristic comprises: a photoelectric detection module, an LC series resonant notch circuit, a first-level resonant frequency-selective amplifier circuit, a second-level frequency-selective network, an AC amplifier module and a DC amplifier module; the photoelectric detection module is used to convert an optical signal into an electrical signal to generate a photocurrent difference signal; the LC series resonant notch circuit comprises a first inductor and a fine-tuning capacitor; one end of the fine-tuning capacitor is connected to one end of the first inductor, and the other end of the fine-tuning capacitor is grounded; the other end of the first inductor is connected between the photoelectric detection module and the first-level resonant frequency-selective amplifier circuit in the resonant balanced zero-beat detector; the LC series resonant notch circuit is used to filter out the signal at the pulse laser repetition frequency in the photocurrent difference signal detected by the photoelectric detection module by adjusting the capacitance value of the fine-tuning capacitor, and send the filtered photocurrent difference signal to the first-level resonant frequency-selective amplifier circuit; the first-level resonant notch circuit is used to filter out the signal at the pulse laser repetition frequency in the photocurrent difference signal detected by the photoelectric detection module by adjusting the capacitance value of the fine-tuning capacitor, and send the filtered photocurrent difference signal to the first-level resonant frequency-selective amplifier circuit; The output end of the vibration type frequency selection amplifier circuit is respectively connected to the input end of the secondary frequency selection network and the input end of the DC amplifier module; the first-level resonance type frequency selection amplifier circuit is used to convert the filtered photocurrent difference signal into a primary voltage signal at the resonant frequency, and amplify the filtered photocurrent difference signal; the output end of the secondary frequency selection network is connected to the first input end of the AC amplifier module; the secondary frequency selection network is used to perform secondary frequency selection on the primary voltage signal at the resonant frequency to obtain the secondary voltage signal at the resonant frequency; at the same time, the primary voltage signal at the resonant frequency is transmitted to the AC amplifier module; the AC amplifier module is used to amplify the secondary voltage signal at the resonant frequency to generate an AC voltage signal at the resonant frequency; the DC amplifier module is used to filter out the DC voltage signal from the primary voltage signal at the resonant frequency, and amplify the filtered DC voltage signal.

[0007] A photoelectric detector printing device comprises: a printed circuit board, an aluminum metal shell and the above-mentioned photoelectric detector. The photoelectric detector is printed on the printed circuit board; the printed circuit board printed with the photoelectric detector is sealed in the aluminum metal shell.

[0008] A photodetector testing device, the testing device comprising: a laser source, a half-wave plate, a polarization beam splitter prism, a first reflector, a second reflector, a first lens, a second lens, a spectrum analyzer, an oscilloscope and the above-mentioned photodetector. The AC voltage output end of the photodetector is connected to the spectrum analyzer, and the DC voltage output end of the photodetector is connected to the oscilloscope. The laser source is used to generate picosecond pulse light with a repetition frequency; the picosecond pulse light is transmitted to the polarization beam splitter prism after passing through the half-wave plate. The polarization beam splitter prism is used to split the picosecond pulse light into two beams, one beam is reflected to the first lens through the first reflector, and the other beam is reflected to the second lens through the second reflector. The first lens is used to focus one split picosecond pulse light onto a photosensitive surface of a photodiode of a photodetection module in the photodetector. The second lens is used to focus another split picosecond pulse light onto another photosensitive surface of a photodiode of the photodetection module in the photodetector. The photodetector is used to send the generated AC voltage signal at the resonant frequency to a spectrum analyzer for noise characteristic analysis, and send the generated DC voltage signal to an oscilloscope for balance analysis of the photodetector.

[0009] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0010] A resonant balanced zero-beat photoelectric detector with a notch characteristic and a printing device and a testing device thereof according to an embodiment of the present invention introduce an LC series resonant notch circuit into the resonant balanced zero-beat detector. By adjusting the fine-tuning capacitor in the LC series resonant notch circuit, the noise at the repetition frequency of the pulse light can be suppressed, thereby ensuring the best notch effect and improving the saturation power and signal-to-noise ratio of the photoelectric detector under pulse light. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0012] Figure 1 A circuit diagram of a photodetector provided in Example 1 of the present invention.

[0013] Figure 2 This is a schematic structural diagram of a photoelectric detector testing device provided in Example 3 of the present invention.

[0014] Figure 3 This is a comparison diagram of the notch effect provided in Example 3 of the present invention.

[0015] Figure 4 This is a graph of the signal-to-noise ratio and saturation power results of the photodetector provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the 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.

[0017] In quantum experiments, since the pulse light has strong energy at its own repetition frequency, the circuit is prone to saturation or even damage to electronic components. Therefore, in the process of photoelectric detection, the signal-to-noise ratio of the detector is not easy to be improved to meet the needs of photoelectric detection. The present invention has developed a unique photodetector with an LC resonant trap circuit structure to suppress the noise at the repetition frequency of the pulse light and improve the saturation power and signal-to-noise ratio of the photodetector. The experimental results show that by fine-tuning the adjustable capacitor parameters of the LC resonant trap to optimize the trap effect, the pulse at the repetition frequency is suppressed by 28.68dB, the saturated light power of the photodetector is increased to 12mW, and the signal-to-noise ratio is increased to 19.60dB, which basically meets the requirements for photodetectors in compressed state generation applications.

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Example 1

[0020] like Figure 1 As shown, a resonant balanced zero-beat photoelectric detector with a notch characteristic in this embodiment includes: a photoelectric detection module, an LC series resonant notch circuit, a first-level resonant frequency-selective amplifier circuit, a second-level frequency-selective network, an AC amplifier module and a DC amplifier module.

[0021] The photoelectric detection module is used to convert the optical signal into an electrical signal to generate a photocurrent difference signal; the LC series resonant trap circuit includes a first inductor and a fine-tuning capacitor; one end of the fine-tuning capacitor is connected to one end of the first inductor, and the other end of the fine-tuning capacitor is grounded; the other end of the first inductor is connected between the photoelectric detection module in the resonant balanced zero-beat detector and the first-level resonant frequency-selective amplifier circuit; the LC series resonant trap circuit is used to filter out the signal at the pulse laser repetition frequency in the photocurrent difference signal detected by the photoelectric detection module by adjusting the capacitance value of the fine-tuning capacitor, and send the filtered photocurrent difference signal to the first-level resonant frequency-selective amplifier circuit; the output end of the first-level resonant frequency-selective amplifier circuit is respectively connected to the input end of the second-level frequency-selective network and the DC amplifier module; The input end of the block; the first-level resonant frequency-selective amplifier circuit is used to convert the filtered photocurrent difference signal into a first-level voltage signal at the resonant frequency, and amplify the filtered photocurrent difference signal; the output end of the second-level frequency-selective network is connected to the first input end of the AC amplification module; the second-level frequency-selective network is used to perform second-level frequency selection on the first-level voltage signal at the resonant frequency to obtain the second-level voltage signal at the resonant frequency; at the same time, the first-level voltage signal at the resonant frequency is transmitted to the AC amplification module; the AC amplification module is used to amplify the second-level voltage signal at the resonant frequency to generate an AC voltage signal at the resonant frequency; the DC amplification module is used to filter out the DC voltage signal from the first-level voltage signal at the resonant frequency, and amplify the filtered DC voltage signal.

[0022] In one example, the photodetection module includes: a pair of photodiodes connected in series and a corresponding power supply module. The middle connection point A of the pair of photodiodes connected in series is connected to the other end of the first inductor. Both ends of the pair of photodiodes connected in series are connected to the power supply device.

[0023] The LC series passive trap is composed of an inductor L and a capacitor C connected in series to ground. Since the inductor has the function of passing low frequencies and blocking high frequencies, and the capacitor has the function of passing high frequencies and blocking low frequencies, when the LC resonates, the circuit only allows signals at the resonant frequency to pass, so the signals at a specific frequency are suppressed.

[0024] The first-stage resonant frequency-selective amplifier circuit includes: a resonant transimpedance structure and a first operational amplifier. The input end of the resonant transimpedance structure and the first input end of the first operational amplifier are both connected to the other end of the first inductor, and the second input end of the first operational amplifier is grounded; the output end of the resonant transimpedance structure and the output end of the first operational amplifier are both connected to the input end of the second-stage frequency-selective network and the input end of the DC amplifier module; the resonant transimpedance structure is used to convert the photocurrent difference signal after filtering by the LC series resonant trap circuit into a first-stage voltage signal at the resonant frequency. The first operational amplifier is used to amplify the photocurrent difference signal after filtering by the LC series resonant trap circuit.

[0025] The resonant transimpedance structure includes: a second inductor, a first resistor, a first capacitor and a second resistor. The second inductor is connected in series with the first resistor and then connected in parallel with the first capacitor and the second resistor respectively; one end of the parallel connection is connected to the other end of the first inductor, and the other end of the parallel connection is connected to the input end of the secondary frequency selection network and the input end of the DC amplifier module respectively.

[0026] The first inductance is Figure 1 The L1 in the figure has a fine-tuning capacitor of Figure 1 The second inductor is C1. Figure 1 In L2, the first resistor is Figure 1 The first capacitor is R1. Figure 1 The second resistor is C2. Figure 1 In Rf, the model of the first operational amplifier is OPA690.

[0027] In another example, the secondary frequency selection network includes: a third inductor, a second capacitor and a third resistor. One end of the third inductor is connected to the output end of the primary frequency selection network, and the other end of the third inductor is connected to one end of the second capacitor; the other end of the second capacitor is respectively connected to one end of the third resistor and the first input end of the AC amplification module; the other end of the third resistor is grounded. The secondary frequency selection network is used to perform secondary frequency selection on the amplified photocurrent difference signal to obtain a secondary voltage signal at the resonant frequency, and transmit the primary voltage signal at the resonant frequency to the AC amplification module.

[0028] The third inductor is Figure 1 The second capacitor is L3 in Figure 1 The third resistor is C3. Figure 1 The model of the second operational amplifier is LMH6624, the second input terminal of the second operational amplifier is connected to one end of the resistor R4 and one end of the resistor R5, the other end of the resistor R4 is connected to the output terminal of the second operational amplifier, and the other end of the resistor R5 is grounded.

[0029] The AC amplification module includes: a second operational amplifier, a fourth resistor and a fifth resistor. The first input end of the second operational amplifier is connected to the output end of the secondary frequency selection network, the other input end of the second operational amplifier is connected to one end of the fourth resistor and one end of the fifth resistor, the other end of the fifth resistor is grounded, and the output end of the second operational amplifier is connected to the other end of the fourth resistor. The output end of the second operational amplifier and the other end of the fourth resistor are connected to a 50Ω resistor as the AC output signal of the photodetector. Among them, the resistance ratio of the fourth resistor and the fifth resistor determines the amplification factor of the AC amplification module. The AC amplification module is used to amplify the secondary voltage signal at the resonant frequency to generate an AC voltage signal at the resonant frequency.

[0030] Please still refer to Figure 1The DC amplifier module includes: a DC filter circuit and a DC amplifier circuit. The input end of the DC filter circuit is connected to the output end of the first-stage resonant frequency selection amplifier circuit and the input end of the second-stage frequency selection network, and the output end of the DC filter circuit is connected to the input end of the DC amplifier circuit. The DC filter circuit is used to filter high-frequency signals and select DC signals. The input end of the DC amplifier circuit is connected to the output end of the DC filter circuit, and the output end of the DC amplifier circuit is connected to a 50Ω resistor as the DC output of the photodetector. The DC amplifier circuit is used to amplify the DC signal selected after passing through the DC filter circuit and output it as a DC voltage signal.

[0031] The DC filtering circuit includes: a sixth resistor and a third capacitor, one end of the sixth resistor is respectively connected to the output end of the first-level frequency selection network and the input end of the second-level frequency selection network, the other end of the sixth resistor is respectively connected to one end of the third capacitor and the input end of the DC voltage amplifier circuit; the other end of the third capacitor is grounded.

[0032] The DC amplifier circuit includes: a third operational amplifier, a seventh resistor and an eighth resistor. The first input end of the third operational amplifier is connected to the output end of the sixth resistor, the other input end of the third operational amplifier is connected to one end of the seventh resistor and one end of the eighth resistor, the output end of the third operational amplifier is connected to the other end of the seventh resistor, and the other end of the eighth resistor is grounded. The third operational amplifier is used to amplify the DC signal after passing through the DC filter circuit to generate a DC voltage signal; the resistance ratio of the seventh resistor and the eighth resistor determines the amplification factor of the DC amplifier circuit.

[0033] The sixth resistor is Figure 1 The third capacitor is R3. Figure 1 The C4 in the figure, the third operational amplifier is OP27, and the seventh resistor is Figure 1 R6 in the figure, the eighth resistor is Figure 1 R7 in.

[0034] The photodetector of the present invention is composed of a photodetection part, a resonant trap part, a two-stage frequency selection network, an AC voltage amplification part, a DC voltage amplification part, etc. In the device, the photocurrents generated by the two photodiodes are subtracted at node A to generate a photocurrent difference signal, which contains shot noise at the resonant frequency and laser noise at the pulse light repetition frequency. The signal is filtered out at the pulse light repetition frequency through an LC series resonant trap network and then enters the frequency selection network. The resonant transimpedance structure replaces the traditional transimpedance TIA structure, and its advantage is that it can simultaneously complete amplification and primary frequency selection, and converts the weak photocurrent signal into a voltage signal at the resonant frequency and amplifies it through the resonant transimpedance part. Then the voltage signal is amplified through secondary frequency selection and voltage.

[0035] The photocurrent difference signal is converted into a voltage signal of a specific frequency through the resonant transimpedance part and the voltage signal is amplified by the operational amplifier. The resonant transimpedance part is composed of L2, C2, R1, and Rf. L2 is selected as 4.7uH, C2 is selected as 10pF, R1 is 50Ω, and Rf is 5000Ω. Finally, a resonant impedance of 3000Ω is obtained to convert the weak photocurrent difference signal into a sufficiently large voltage signal. L3, C3, and R2 form a series resonant network for secondary frequency selection. L3 is 1uH, C3 is 68pF, and R2 is 50Ω. After two-stage frequency selection, the voltage signal is amplified by the voltage amplifier LMH6624 (TI Company) for the second stage, and the amplification factor is A. u Determined by R4 and R5, Finally, the AC signal is impedance matched through a 50Ω resistor and connected to a spectrum analyzer for noise characteristic analysis. R3 and C4 play the role of AC / DC separation here, filtering out the DC signal and amplifying it through a voltage amplifier composed of an op amp OP27 and R6 and R7.

[0036] Since the inductor L1 and capacitor C1 of the resonant notch part have a great influence on the electronic noise, and their numerical accuracy also has a great influence on the notch effect, the present invention carefully selects the capacitor and inductor components, and finally selects a combination of an 820nH inductor L1 and a 4.9pF capacitor C1. The capacitor is replaced by a 2.5pF-6pF fine-tuning capacitor. The fine-tuning capacitor can better select a suitable notch frequency and a good notch depth.

[0037] Example 2

[0038] In order to apply the photoelectric detector corresponding to the above-mentioned embodiment 1 to achieve corresponding functions and technical effects, a photoelectric detector printing device is provided below. The printing device includes: a printed circuit board, an aluminum metal housing and the photoelectric detector of embodiment 1.

[0039] The photodetector is printed on a printed circuit board; the printed circuit board with the photodetector is sealed in an aluminum metal housing.

[0040] The reasonable layout of PCB (Printed Circuit Board) is very important in achieving stable circuit performance, especially in high-frequency signal applications. All traces around the operational amplifier should be as short as possible, and the traces near the resonant circuit should be as short as possible to reduce the influence of parasitic capacitance. The two photodiodes are laid out back to back, and the power line and signal line are on the top and bottom layers respectively to avoid electromagnetic interference. The prepared detector circuit board is sealed in an aluminum metal shell to reduce interference from external electromagnetic waves and ensure that the detector can work normally.

[0041] Example 3

[0042] The embodiment of the present invention provides a photoelectric detector testing device, such as Figure 2 As shown, the testing device includes: a laser source, a half-wave plate, a polarization beam splitter, a first reflector, a second reflector, a first lens, a second lens, a spectrum analyzer, an oscilloscope and the photodetector of Example 1.

[0043] The AC voltage output end of the photodetector is connected to the spectrum analyzer, and the DC voltage output end of the photodetector is connected to the oscilloscope. The laser source is used to generate picosecond pulse light with a repetition frequency; the picosecond pulse light is transmitted to the polarization beam splitter prism after passing through the half-wave plate. The polarization beam splitter prism is used to split the picosecond pulse light into two beams, one beam is reflected to the first lens through the first reflector, and the other beam is reflected to the second lens through the second reflector. The first lens is used to focus the picosecond pulse light after one beam split onto the photosensitive surface of a photodiode of the photoelectric detection module in the photodetector. The second lens is used to focus the picosecond pulse light after another beam split onto the photosensitive surface of another photodiode of the photoelectric detection module in the photodetector. The photodetector is used to send the generated AC voltage signal at the resonant frequency to the spectrum analyzer for noise characteristic analysis, and send the generated DC voltage signal to the oscilloscope for balance analysis of the photodetector.

[0044] Figure 2 Here, Laser represents a laser source, HWP represents a half-wave plate, PBS represents a polarization beam splitter, M1 represents a first reflector, M2 represents a second reflector, L1 represents a first lens, L2 represents a second lens, PD1 and PD2 represent a pair of photodiodes, DC represents a direct current voltage signal, AC represents an alternating current voltage signal, OSC represents an oscilloscope, and SA represents a spectrum analyzer.

[0045] The photodetector testing device according to the embodiment of the present invention can test the performance of the notch part of the photodetector.

[0046] The test experiment is described as follows:

[0047] After the picosecond pulse light with a repetition frequency of 80MHz is split 50:50 by a half-wave plate and PBS, it is focused onto the photosensitive surfaces of photodiodes PD1 and PD2 through two lenses L1 and L2 with a focal length of 50mm. The splitting ratio of PBS is changed by rotating the half-wave plate to balance the responses of the two photodiode probes. The DC and AC outputs of the detector are connected to an oscilloscope and a spectrum analyzer respectively to test the performance of the detector.

[0048] Experimental test results:

[0049] The present invention first tests the performance of the detector notch part. Under a total optical power of 0.5mW, the two sides are 0.25mW respectively. The present invention blocks one side of the detector, and only one side works to test the notch effect. Figure 3 As shown in the figure, the red curve is a single-sided pulse tested without a trap circuit, and the pulse height is 57.68dB. When the detector has a trap circuit to perform trap work, the pulse height is only 29.00dB. It can be clearly seen that the pulse at 80MHz is well suppressed. The experiment successfully obtained a trap effect of 28.68dB. This structure plays a great role in improving the saturated optical power and the signal-to-noise ratio.

[0050] Figure 3 The black curve is the electronic noise without the notch circuit, the red curve is the 80MHz pulse when only one side works without the notch circuit, the green curve is the electronic noise with the notch circuit, and the blue curve is the 80MHz pulse after the notch. Using an Agilent spectrum analyzer, the RBW is 100kHz, the VBW is 100Hz, and the sweep time is 400ms.

[0051] Figure 4 The signal-to-noise ratio and saturation power test results of the detector. Because the trap circuit effectively suppresses the laser repetition frequency, the saturation effect caused by the high energy at the laser repetition frequency is reduced. Finally, the saturation optical power of the detector reaches 12mW and a signal-to-noise ratio of 19.60dB is obtained.

[0052] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A resonant balanced zero-beat photodetector with notch characteristics, characterized in that: include: Photoelectric detection module, LC series resonant trap circuit, first-level resonant frequency-selective amplifier circuit, second-level frequency-selective network, AC amplifier module and DC amplifier module; The photoelectric detection module is used to convert the optical signal into an electrical signal to generate a photocurrent difference signal; The LC series resonant trap circuit includes a first inductor and a fine-tuning capacitor; one end of the fine-tuning capacitor is connected to one end of the first inductor, and the other end of the fine-tuning capacitor is grounded; the other end of the first inductor is connected between the photoelectric detection module in the resonant balanced zero-beat detector and the first-stage resonant frequency-selective amplifier circuit; The LC series resonant trap circuit is used to filter out the signal at the pulse laser repetition frequency in the photocurrent difference signal detected by the photoelectric detection module by adjusting the capacitance value of the fine-tuning capacitor, and send the filtered photocurrent difference signal to the first-level resonant frequency-selective amplifier circuit; The output end of the first-level resonant frequency-selective amplifier circuit is respectively connected to the input end of the second-level frequency-selective network and the input end of the DC amplifier module; the first-level resonant frequency-selective amplifier circuit is used to convert the filtered photocurrent difference signal into a first-level voltage signal at the resonant frequency, and amplify the filtered photocurrent difference signal; The output end of the secondary frequency selection network is connected to the first input end of the AC amplification module; the secondary frequency selection network is used to perform secondary frequency selection on the primary voltage signal at the resonant frequency to obtain the secondary voltage signal at the resonant frequency; and at the same time, transmit the primary voltage signal at the resonant frequency to the AC amplification module; The AC amplification module is used to amplify the secondary voltage signal at the resonant frequency to generate an AC voltage signal at the resonant frequency; The DC amplification module is used to filter out a DC voltage signal from the primary voltage signal at the resonant frequency, and amplify the filtered DC voltage signal.

2. The resonant balanced zero-beat photodetector with notch characteristics according to claim 1, characterized in that: The photoelectric detection module includes: a pair of photodiodes connected in series and a power supply device; The middle connection point of a pair of photodiodes connected in series is connected to the other end of the first inductor; Both ends of a pair of photodiodes connected in series are connected to a power supply device.

3. The resonant balanced zero-beat photodetector with notch characteristics according to claim 1, characterized in that: The first-stage resonant frequency-selective amplifier circuit comprises: a resonant transimpedance structure and a first operational amplifier; The input end of the resonant transimpedance structure and the first input end of the first operational amplifier are both connected to the other end of the first inductor, and the second input end of the first operational amplifier is grounded; the output end of the resonant transimpedance structure and the output end of the first operational amplifier are both connected to the input end of the secondary frequency selection network and the input end of the DC amplification module; The resonant transimpedance structure is used to convert the photocurrent difference signal after being filtered by the LC series resonant trap circuit into a primary voltage signal at the resonant frequency; The first operational amplifier is used to amplify the photocurrent difference signal after being filtered by the LC series resonant trap circuit.

4. The resonant balanced zero-beat photodetector with notch characteristics according to claim 3, characterized in that: The resonant transimpedance structure includes: a second inductor, a first resistor, a first capacitor and a second resistor; The second inductor is connected in series with the first resistor and then connected in parallel with the first capacitor and the second resistor respectively; one end of the parallel connection is connected to the other end of the first inductor, and the other end of the parallel connection is connected to the input end of the secondary frequency selection network and the input end of the DC amplifier module respectively.

5. The resonant balanced zero-beat photodetector with notch characteristics according to claim 1, characterized in that: The secondary frequency selection network includes: a third inductor, a second capacitor and a third resistor; One end of the third inductor is connected to the output end of the first-level frequency selection network, and the other end of the third inductor is connected to one end of the second capacitor; the other end of the second capacitor is respectively connected to one end of the third resistor and the first input end of the AC amplification module; the other end of the third resistor is grounded.

6. The resonant balanced zero-beat photodetector with notch characteristics according to claim 1, characterized in that: The AC amplification module includes: a second operational amplifier, a fourth resistor and a fifth resistor; A first input terminal of the second operational amplifier is connected to the output terminal of the secondary frequency selection network, another input terminal of the second operational amplifier is connected to one end of the fourth resistor and one end of the fifth resistor, an output terminal of the second operational amplifier is connected to the other end of the fourth resistor, and the other end of the fifth resistor is grounded; The second operational amplifier is used to amplify the secondary voltage signal at the resonant frequency to generate an AC voltage signal at the resonant frequency.

7. The resonant balanced zero-beat photodetector with notch characteristics according to claim 1, characterized in that: The DC amplification module includes: a DC filtering circuit and a DC amplification circuit; The DC filter circuit includes a sixth resistor and a third capacitor; one end of the sixth resistor is respectively connected to the output end of the first-level resonant frequency-selective amplifier circuit and the input end of the second-level frequency-selective network, and the other end of the sixth resistor is respectively connected to one end of the third capacitor and the input end of the DC voltage amplifier circuit; the other end of the third capacitor is grounded; The DC filter circuit is used to filter out the high-frequency signal in the primary voltage signal at the resonant frequency and select the DC signal; The DC amplifier circuit is used to amplify the DC signal selected after passing through the DC filter circuit and output it as a DC voltage signal.

8. The resonant balanced zero-beat photodetector with notch characteristics according to claim 7, characterized in that: The DC amplifying circuit comprises: a third operational amplifier, a seventh resistor and an eighth resistor; A first input terminal of the third operational amplifier is connected to the other end of the sixth resistor, another input terminal of the third operational amplifier is connected to one end of the seventh resistor and one end of the eighth resistor, an output terminal of the third operational amplifier is connected to the other end of the seventh resistor, and the other end of the eighth resistor is grounded; The third operational amplifier is used to amplify the DC signal after passing through the DC filter circuit to generate a DC voltage signal.

9. A printing device for a resonant balanced zero-beat photodetector with notch characteristics, characterized in that: The printed device comprises: a printed circuit board, an aluminum metal housing, and a resonant balanced zero-beat photodetector with notch characteristics according to any one of claims 1 to 8; The resonant balanced zero-beat photoelectric detector with notch characteristics is printed on the printed circuit board; the printed circuit board printed with the photoelectric detector is sealed in an aluminum metal shell.

10. A resonant balanced zero-beat photodetector test device with notch characteristics, characterized in that: The testing device comprises: a laser source, a half-wave plate, a polarization beam splitter, a first reflector, a second reflector, a first lens, a second lens, a spectrum analyzer, an oscilloscope, and a photodetector as described in any one of claims 1 to 8; The AC voltage output terminal of the photodetector is connected to a spectrum analyzer, and the DC voltage output terminal of the photodetector is connected to an oscilloscope; The laser source is used to generate picosecond pulse light with a repetition frequency; the picosecond pulse light is transmitted to the polarization beam splitter prism after passing through a half-wave plate; The polarization beam splitter prism is used to split the picosecond pulse light into two beams, one beam is reflected to the first lens via the first reflector, and the other beam is reflected to the second lens via the second reflector; The first lens is used to focus a split picosecond pulse light onto a photosensitive surface of a photodiode of a photoelectric detection module in the photoelectric detector; The second lens is used to focus the other split picosecond pulse light onto another photodiode photosensitive surface of the photoelectric detection module in the photoelectric detector; The photodetector is used to send the generated AC voltage signal at the resonant frequency to a spectrum analyzer for noise characteristic analysis, and send the generated DC voltage signal to an oscilloscope for balance analysis of the photodetector.

Images