Balanced homodyne detector for high-entropy high-speed continuous-variable quantum random number generation

Abstract

The application provides a balanced homodyne detector for high-entropy high-speed continuous variable quantum random number generation, which is composed of a signal processing module and a signal amplification module; the signal processing module comprises a photocurrent difference signal generation and AC / DC separation module, a photocurrent difference signal is generated through a series connection of photodiodes and related elements, and AC / DC signal separation is completed with the help of a blocking capacitor and related elements; the AC / DC separation module completes the function selection of the module through switch control, disconnects the switch to block the influence of the DC part noise on the AC part, and closes the switch to detect the DC signal; the signal amplification module comprises a cascaded RF AC amplification module and a co-directional proportional amplification DC amplification module, the cascaded RF AC amplification module realizes high-gain amplification of the AC signal by using two-stage RF amplifiers and related elements; and the co-directional proportional amplification DC amplification module adopts a low-noise amplifier and related elements to realize accurate detection and amplification of the DC signal. The application solves the problems of low generation rate, poor purity and quality of random numbers in the current vacuum state random number generation.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of quantum information technology, and particularly relates to a balanced homodyne detector for high-entropy high-speed continuous variable quantum random number generation. BACKGROUND

[0002] With the rapid development of quantum information technology, the balanced homodyne detector is a very important device in quantum random number generation. The continuous variable quantum random number generation system generates random numbers by measuring the amplitude and phase of the light field and other continuous variables. The upper limit of the random number generation rate is determined by the product of the quantum minimum entropy and the sampling rate. With the bottleneck of the scheme for improving the minimum entropy, the limiting factor of the random number generation rate returns to the core problem - the sampling rate, which is limited by the bandwidth of the balanced homodyne detector. Although the vacuum state quadrature component is in the form of shot noise, the bandwidth of the noise power spectrum is theoretically infinite, but the value range of the sampling rate is not infinite. According to the Nyquist sampling law, when the sampling rate exceeds twice the bandwidth of the balanced homodyne detector, there will be autocorrelation between the sampling points, which will affect the randomness of the random number, so the sampling rate is limited by the bandwidth of the balanced homodyne detector.

[0003] On the other hand, in order to more effectively extract the quantum entropy source based on the balanced homodyne detection, not only the bandwidth of the balanced homodyne detector needs to be further improved, but also the signal-to-noise ratio within the bandwidth needs to be greater than 10dB. If the signal-to-noise ratio of the detector is low, more noise will be mixed in the measurement result, which may cause the generated random number to be not "random" enough. In order to effectively reduce the noise influence from the electronic devices or external interference sources and ensure that the detector only responds to the target quantum signal, the common-mode rejection ratio of the balanced homodyne detector needs to be improved. The performance of the BHD needs to be more comprehensive: not only high bandwidth (GHz level) is needed to improve the generation rate of the random number, but also high signal-to-noise ratio (greater than 10dB) and high common-mode rejection ratio (greater than 25dB) are needed to ensure the purity and quality of the random number. Therefore, the research on the balanced homodyne detector has become increasingly important. SUMMARY

[0004] The application aims at the problems of low random number generation rate, poor purity and quality of the random number of the current vacuum state, and provides a new high-performance balanced homodyne detector for high-entropy high-speed continuous variable quantum random number generation.

[0005] The technical scheme of the application is as follows:

[0006] A balanced homodyne detector for high-entropy high-speed continuous variable quantum random number generation is composed of a signal processing module and a signal amplification module; the signal processing module includes a photocurrent difference signal generation and AC / DC separation module, which generates a photocurrent difference signal through a series connection of photodiodes and related elements, and separates AC / DC signals with the help of a blocking capacitor and related elements; the AC / DC separation module selects the module function through a switch control method, disconnects the switch to block the influence of the DC part noise on the AC part, and closes the switch to detect the DC signal; the signal amplification module includes a cascaded RF AC amplification module and a co-directional proportional amplification DC amplification module, the cascaded RF AC amplification module uses two-stage RF amplifiers and related elements to realize high-gain amplification of AC signals; and the co-directional proportional amplification DC amplification module uses a low-noise amplifier and related elements to realize accurate detection and amplification of DC signals.

[0007] Further, the photocurrent difference signal generation module includes a first photodiode PD1, a second photodiode PD2, a power filter capacitor C1, a current-limiting resistor R1, a filter capacitor C2, a power filter capacitor C4, a current-limiting resistor R2, and a filter capacitor C3.

[0008] The cathode of the first photodiode PD1 is connected to one end of the current-limiting resistor R1 and one end of the filter capacitor C2, the other end of the current-limiting resistor R1 is connected to one end of the power filter capacitor C1 at a positive voltage, and the other end of the power filter capacitor C1 is connected to the other end of the filter capacitor C2 to ground.

[0009] The anode of the second photodiode PD2 is connected to one end of the current-limiting resistor R2 and one end of the filter capacitor C3, the other end of the current-limiting resistor R2 is connected to one end of the power filter capacitor C4 at a negative voltage, and the other end of the power filter capacitor C4 is connected to the other end of the filter capacitor C3 to ground.

[0010] The anode of the first photodiode PD1 is connected to the cathode of the second photodiode PD2, and the junction point is a; the junction point a is connected to the input end of the AC / DC separation module.

[0011] Further, the AC / DC separation module includes a blocking capacitor C5, a switch SW, a blocking inductor L1, and a terminal resistor R3.

[0012] One end of the switch SW is connected to the input end of the blocking capacitor C5, the other end is connected to the input end of the blocking inductor L1, the output end of the blocking capacitor C5 is connected to the cascaded RF AC amplification module, the output end of the blocking inductor L1 forms a node b with the input end of the terminal resistor R3, and the node b is connected to the co-directional proportional amplification DC amplification module; and the output end of the terminal resistor R3 is grounded.

[0013] Further, the cascade radio frequency alternating current amplification module comprises: a first radio frequency amplifier U1, a second radio frequency amplifier U2, a cross induction L2, a cross induction L3, a direct current blocking capacitor C6, a direct current blocking capacitor C7, a power filter capacitor C8, a bypass capacitor C9, a power filter capacitor C10, a bypass capacitor C11;

[0014] The first radio frequency amplifier U1 comprises: a pin 1, a pin 2, a pin 3, a pin 4, a pin 5, a pin 6; the pin 1 and the pin 2 of the first radio frequency amplifier U1 are commonly connected to the ground, the pin 3 of the first radio frequency amplifier U1 is connected with the output end of the alternating current direct current separation module, the pin 4 of the first radio frequency amplifier U1 is connected with the input end of the power filter capacitor C8 to the positive voltage +5v, the output end of the power filter capacitor C8 is grounded, the pin 5 of the first radio frequency amplifier U1 is connected to the ground, and the pin 6 of the first radio frequency amplifier U1 is connected with the input end of the direct current blocking capacitor C6; the input end of the cross induction L2 is connected with the input end of the direct current blocking capacitor C6; the output end of the cross induction L2 is connected with the input end of the bypass capacitor C9; the output end of the bypass capacitor C9 is grounded;

[0015] The second radio frequency amplifier U2 comprises: a pin 1, a pin 2, a pin 3, a pin 4, a pin 5, a pin 6; the pin 1 and the pin 2 of the second radio frequency amplifier U2 are commonly connected to the ground, the pin 3 of the second radio frequency amplifier U2 is connected with the output end of the direct current blocking capacitor C6, the pin 4 of the second radio frequency amplifier U2 is connected with the input end of the power filter capacitor C10 to the positive voltage +5v, the output end of the power filter capacitor C10 is grounded, the pin 5 of the second radio frequency amplifier U2 is connected to the ground, the pin 6 of the second radio frequency amplifier U2 is connected with the input end of the direct current blocking capacitor C7, the input end of the cross induction L3 is connected with the input end of the direct current blocking capacitor C7, the output end of the cross induction L3 is connected with the input end of the bypass capacitor C11, and the output end of the bypass capacitor C11 is grounded. The output end of the direct current blocking capacitor C7 is connected with the alternating current signal output end AC-Out.

[0016] Further, the same direction proportional amplification direct current amplification module comprises: a low noise amplifier U3, a current limiting resistor R4, a filter capacitor C12, a power filter capacitor C13, a power filter capacitor C14, a feedback resistor R6, a resistor R5, and an output resistor R7.

[0017] The low-noise amplifier U3 comprises a pin 2, a pin 3, a pin 4, a pin 6 and a pin 7; the pin 2 of the low-noise amplifier U3 is connected with the input end of a resistor R5, the output end of the resistor R5 is grounded, the pin 3 of the low-noise amplifier U3 is connected with the output end of a current-limiting resistor R4 and the input end of a filter capacitor C12, the pin 4 of the low-noise amplifier U3 is connected with a negative voltage -5v through a power filter capacitor C13, the pin 6 of the low-noise amplifier U3 is connected with a feedback resistor R6 and an output resistor R7, the pin 7 of the low-noise amplifier U3 is connected with a positive voltage +5v through a power filter capacitor C14, and the output end of the output resistor R7 is connected with a direct-current signal output end DC-Out.

[0018] Further, the model of the first radio frequency amplifier U1 and the second radio frequency amplifier U2 is a radio frequency amplification chip ABA-52563.

[0019] Further, the model of the first photoelectric diode PD1 and the second photoelectric diode PD2 is LSIPD-LD50.

[0020] Further, the model of the SW is DSIC01LS-P, and the SW is a single-pole single-throw switch.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] The present application realizes the improvement of the signal-to-noise ratio of the balanced homodyne detector. The photocurrent difference signal generation module is designed in the form of series subtraction of the first photoelectric diode PD1 and the second photoelectric diode PD2. Such subtraction design can not only reduce the classical noise, but also reduce another noise source, 1 / f flicker noise.

[0023] In the present application, the function under different requirements is realized. The AC-DC separation module is designed in the form of a switch to complete the function selection of the balanced homodyne detector. When the switch is open, the influence of the noise in the direct-current amplification circuit on the alternating-current amplification circuit can be greatly reduced, thereby improving the signal-to-noise ratio. When the switch is closed, the direct-current part is amplified by the voltage amplifier and used for detecting the intensity of incident light.

[0024] In the present application, high-gain alternating-current amplification is realized. The cascaded radio frequency alternating-current amplification module of the balanced homodyne detector is designed by selecting a low-noise and high-gain radio frequency amplifier and adopting a two-stage cascaded amplification structure to realize high-gain alternating-current amplification.

[0025] In the present application, the accurate detection and amplification of the direct-current signal are realized. The co-directional proportional amplification direct-current amplification module of the balanced homodyne detector is designed by selecting a low-noise and low-drift operational amplifier and adopting a co-directional proportional amplification structure, which can ensure the accurate detection and amplification of the direct-current signal.

[0026] This invention effectively improves the common-mode rejection ratio of the balanced zero-beat detector. In the PCB design of the balanced zero-beat detector, the circuit routing and layout are replanned. A "Y"-shaped distribution structure is optimized between the first photodiode PD1 and the second photodiode PD2 and the DC blocking capacitor C5 to achieve high symmetry.

[0027] This invention achieves miniaturization of the balanced zero-beat detector. It utilizes the Rogers 4350, suitable for high-frequency amplification and only 0.51mm thick, and selects a smaller 0402 capacitor package. Attached Figure Description

[0028] The accompanying drawings illustrate various embodiments generally by way of example rather than limitation, and are used, together with the specification and claims, to explain embodiments of the invention. Where appropriate, the same reference numerals are used in all drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the apparatus or method.

[0029] Figure 1 This is a structural diagram of the novel high-performance balanced zero-step detector described in this invention;

[0030] Figure 2 The circuit diagram of the novel high-performance balanced zero-beat detector described in this invention is shown below.

[0031] Figure 3 This is a diagram of the photocurrent difference signal generation module described in this invention;

[0032] Figure 4 This is a diagram of the cascaded radio frequency AC amplifier module described in this invention;

[0033] Figure 5 This is a diagram of the same-direction proportional DC amplifier module described in this invention;

[0034] Figure 6 This is a diagram of the experimental setup for testing vacuum-state shot noise according to the present invention;

[0035] Figure 7 The graph shows the results of detecting increased shot noise in different frequency bands using the novel high-performance balanced zero-beat detector of this invention.

[0036] Figure 8 The signal-to-noise ratio result of the control switch of the novel high-performance balanced zero-beat detector shown in this invention completing the function selection is shown in the figure.

[0037] Figure 9 The figure shows the experimental results of the common-mode rejection ratio of the novel high-performance balanced zero-beat detector shown in this invention.

[0038] Figure 6 M: 5-wavelength 1550 nm single-mode semiconductor continuous wave laser, 6-any waveform signal generator, 7-intensity modulator, 8-variable optical attenuator, 9-half wave plate, 10-polarization beam splitter, 11-half wave plate, 12-polarization beam splitter, 13-photodiode PD1, 14-photodiode PD2, 15-balance zero beat detector, 16-spectrum analyzer, 17-oscilloscope. DETAILED DESCRIPTION

[0039] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0040] The designed circuits of the present application are all printed on a double-layer circuit board, the circuit board material is Rogers 4350 with good high-frequency performance, and the via connection is connected to the GND ground, and the power supply and ground layer adopt full copper laying process.

[0041] AC-Out and DC-Out adopt SMA radio frequency interface.

[0042] Embodiment one

[0043] A balanced zero beat detector for high-entropy high-speed continuous variable quantum random number generation, specifically comprising: a photocurrent difference signal generation module 1, an AC-DC separation module 2, a cascaded RF AC amplification module 3, a co-directional proportional amplification DC amplification module 4.

[0044] As shown in Figure 2 The photocurrent difference signal generation module 1 includes a first photodiode PD1, a second photodiode PD2, a power filter capacitor C1, a current limiting resistor R1, a filter capacitor C2, a power filter capacitor C4, a current limiting resistor R2, and a filter capacitor C3; the AC-DC separation module 2 includes a DC blocking capacitor C5, a switch SW, an AC blocking inductor L1, and a terminal resistor R3; the cascaded RF AC amplification module 3 includes: a first RF amplifier U1, a second RF amplifier U2, an AC blocking inductor L2, an AC blocking inductor L3, a DC blocking capacitor C6, a DC blocking capacitor C7, a power filter capacitor C8, a bypass capacitor C9, a power filter capacitor C10, and a bypass capacitor C11; the co-directional proportional amplification DC amplification module 4 includes: a low-noise amplifier U3, a current limiting resistor R4, a filter capacitor C12, a power filter capacitor C13, a power filter capacitor C14, a feedback resistor R6, a resistor R5, and an output resistor R7.

[0045] The cathode of the first photodiode PD1 is connected to a positive voltage, the anode of the second photodiode PD2 is connected to a negative voltage, the anode of the first photodiode PD1 is connected to the cathode of the second photodiode PD2, and the node is a; the node a is connected to the input end of the direct current blocking capacitor C5, the output end of the direct current blocking capacitor C5 is connected to the first radio frequency amplifier U1, the first radio frequency amplifier U1 is connected to the input end of the direct current blocking capacitor C6, the output end of the direct current blocking capacitor C6 is connected to the input end of the second radio frequency amplifier U2, the output end of the second radio frequency amplifier U2 is connected to the input end of the direct current blocking capacitor C7, and the output end of the direct current blocking capacitor C7 is connected to the alternating current signal output end AC-Out; the input end of the direct current blocking capacitor C5 is connected to the switch SW, the other side of the switch is connected to the input end of the alternating current blocking inductor L1, the output end of the alternating current blocking inductor L1 is connected to the input end of the terminal resistor R3, and the node is b; the other side of the terminal resistor R3 is grounded; the input end of the current limiting resistor R4 is connected to the node b, the output end of the current limiting resistor R4 is connected to the input end of the filter capacitor C12 and the input end of the low noise amplifier U3, the output end of the filter capacitor C12 is grounded, the input end of the low noise amplifier U3 is connected to the input end of the output resistor R7, and the output end of the output resistor R7 is connected to the direct current signal output end DC-Out;

[0046] As shown in Figure 3 The cathode of the first photodiode PD1 is connected to one end of the current limiting resistor R1 and one end of the filter capacitor C2, the other end of the current limiting resistor R1 is connected to one end of the power filter capacitor C1 to a positive voltage, and the other end of the power filter capacitor C1 is connected to the other end of the filter capacitor C2 to ground.

[0047] The anode of the second photodiode PD2 is connected to one end of the current limiting resistor R2 and one end of the filter capacitor C3, the other end of the current limiting resistor R2 is connected to one end of the power filter capacitor C4 to a negative voltage, and the other end of the power filter capacitor C4 is connected to the other end of the filter capacitor C3 to ground.

[0048] As shown in Figure 4The first radio frequency amplifier U1 is a radio frequency amplification chip ABA-52563, including pin 1, pin 2, pin 3, pin 4, pin 5, pin 6; the pin 1 and pin 2 of the radio frequency amplification chip ABA-52563 are commonly connected to the ground, the pin 3 of the radio frequency amplification chip ABA-52563 is connected with the output end of the direct current blocking capacitor C5, one end of the power filter capacitor C8 is connected to the positive voltage +5v, the other end of the power filter capacitor C8 is grounded, the pin 5 of the radio frequency amplification chip ABA-52563 is connected to the ground, and the pin 6 of the radio frequency amplification chip ABA-52563 is connected with the direct current blocking capacitor C6; the direct current blocking capacitor C6 is used to avoid the mixing of the direct current power supply of the radio frequency amplification chip ABA-52563 and the alternating current signal after the first stage amplification into the second stage amplification circuit, and the alternating current blocking inductor L2 is used to prevent the alternating current signal after the first stage amplification from entering the power supply of the first radio frequency amplifier U1, so that the power supply is unstable, thereby in turn affecting the stability of the first radio frequency amplifier U1.

[0049] The second radio frequency amplifier U2 is a radio frequency amplification chip ABA-52563, including pin 1, pin 2, pin 3, pin 4, pin 5, pin 6; the pin 1 and pin 2 of the radio frequency amplification chip ABA-52563 are commonly connected to the ground, the pin 3 of the radio frequency amplification chip ABA-52563 is connected with the output end of the direct current blocking capacitor C6, one end of the power filter capacitor C10 is connected to the positive voltage +5v, the other end of the power filter capacitor C10 is grounded, the pin 5 of the radio frequency amplification chip ABA-52563 is connected to the ground, and the pin 6 of the radio frequency amplification chip ABA-52563 is connected with the direct current blocking capacitor C7. The alternating current blocking inductor L3 is used to prevent the alternating current signal after the second stage amplification from entering the power supply of the second radio frequency amplifier U2, so that the power supply is unstable, thereby in turn affecting the stability of the second radio frequency amplifier U2.

[0050] As Figure 5As shown, the low noise amplifier U3 is a low noise amplifier chip OP 27 including pin 2, pin 3, pin 4, pin 6, pin 7;The pin 2 of the low noise amplifier U3 is connected with the resistance R5, the pin 3 of the low noise amplifier U3 is connected with the output end of the current limiting resistance R4 and the input end of the filter capacitor C12, the pin 4 of the low noise amplifier U3 is connected with the negative voltage-5v after the power filter capacitor C13, the pin 6 of the low noise amplifier U3 is connected with the feedback resistance R6 and the output resistance R7, and the pin 7 of the low noise amplifier U3 is connected with the positive voltage+5v after the power filter capacitor C14. Since the direct current signal is a voltage signal, a proportional amplification circuit is designed with a voltage amplifier as the core, a same-direction amplification structure is adopted, the direct current signal enters the positive input end of the voltage amplifier after the current limiting resistance R4;The feedback resistance R6 and the resistance R5 jointly determine the amplification multiple of the direct current signal;The amplified direct current signal is output through the output resistance R7. OP 27 adopts dual power supply, and the power supply is ±5V.

[0051] Example two

[0052] Figure 6 It is the experimental device graph for testing the vacuum state of the present application. Wherein 5 is a single mode semiconductor continuous wave laser with wavelength 1550nm, which is used to output a continuous wave light source as a local oscillation light source of a balanced homodyne detector;6 is an arbitrary waveform generator, which outputs a sinusoidal signal;7 is an intensity modulator, which linearly modulates the local oscillation light source;8 is a variable optical attenuator, which is used to adjust the intensity of the optical signal;9 and 11 are half-wave plates, which are used to adjust the polarization direction of the incident light;10 and 12 are polarization beam splitters, which are used to divide the incident light into two linearly polarized lights;13 and 14 are photodiodes, which are used to convert the optical signal into an electrical signal;15 is a balanced homodyne detector, which tests the shot noise;16 is a spectrum analyzer, which is used to measure and analyze the AC-Out output;17 is an oscilloscope, which is used to monitor the direct current signal of the DC-Out output.

[0053] Figure 7 It is the result graph of the balanced homodyne detector shown in the present application detecting the shot noise lifting in different frequency bands. The spectrum from top to bottom is: the incident light power is 2mW, the incident light power is 1mW, the incident light power is 0.5mW, the balanced homodyne detector electronic noise, the base noise of the spectrum analyzer. It can be seen that, with the increase of the incident light power, the spectrum shows a lifting trend, when the incident light power doubles, the spectrum lifts 3dB, when the incident light power is 2mW, the signal-to-noise ratio reaches 41.5dB at 1.75GHz, realizing high-gain AC amplification, and the effective bandwidth reaches GHz level. Strong noise or interference signals appear at certain frequencies. These spikes may be caused by radio frequency interference in the external environment.

[0054] Figure 8 The figure is the experimental result of the signal-to-noise ratio of the balanced homodyne detector shown in the application. The spectrum from top to bottom is: when the incident light power is 1 mW and the switch SW is open, when the incident light power is 1 mW and the switch SW is closed, the electronic noise of the balanced homodyne detector, and the base noise of the spectrum analyzer. When the switch SW is in the open state, the electronic noise of the AC branch is significantly reduced because the inherent shunt of the same proportional amplification DC amplification module is eliminated, so the signal-to-noise ratio of the balanced homodyne detector is high. When the switch SW is closed, it can be seen that the noise caused by the same proportional amplification DC amplification module of the balanced homodyne detector makes the signal-to-noise ratio in the working bandwidth of the balanced homodyne detector low.

[0055] Figure 9 The figure is the experimental result of the common-mode rejection ratio of the balanced homodyne detector shown in the application. The spectrum from top to bottom is: both arms pass 0.1 mW of light, one arm passes 0.1 mW of light, the electronic noise of the balanced homodyne detector, and the base noise of the spectrum analyzer. When both photodiodes PD1 and PD2 pass the same incident light 0.1 mW, that is, double-ended input, AC-Out is the amplified common-mode signal; when one photodiode PD1 passes 0.1 mW of incident light and the other photodiode does not pass incident light, that is, single-ended input, AC-Out is the amplified differential-mode signal. It can be seen that at 100 MHz, the common-mode rejection ratio is 30 dB, indicating that the balanced homodyne detector has good ability to amplify the differential-mode signal and suppress the common-mode signal interference.

[0056] The above is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the application within the technical range disclosed by the application, which should be covered within the protection scope of the application.

Claims

1. A balanced homodyne detector for high-entropy high-speed continuous-variable quantum random number generation, characterized in that, It consists of a signal processing module and a signal amplification module. The signal processing module includes a photocurrent difference signal generation and AC / DC separation module. It generates a photocurrent difference signal through a series connection of photodiodes and related components, and completes AC / DC signal separation with the help of DC blocking capacitors and related components. The AC / DC separation module selects its function through a switch control method. Opening the switch blocks the influence of DC noise on the AC part, and closing the switch detects the DC signal. The signal amplification module includes a cascaded radio frequency AC amplification module and a co-directional proportional amplification DC amplification module. The cascaded radio frequency AC amplification module uses two stages of radio frequency amplifiers and related components to achieve high-gain amplification of the AC signal. The co-directional proportional amplification DC amplification module uses a low-noise amplifier and related components to achieve accurate detection and amplification of the DC signal. The photocurrent difference signal generation module includes a first photodiode PD1, a second photodiode PD2, a power supply filter capacitor C1, a current limiting resistor R1, a filter capacitor C2, a power supply filter capacitor C4, a current limiting resistor R2, and a filter capacitor C3. The cathode of the first photodiode PD1 is connected to one end of the current-limiting resistor R1 and one end of the filter capacitor C2. The other end of the current-limiting resistor R1 is connected to one end of the power supply filter capacitor C1 at a positive voltage. The other end of the power supply filter capacitor C1 and the other end of the filter capacitor C2 are connected to ground. The anode of the second photodiode PD2 is connected to one end of the current-limiting resistor R2 and one end of the filter capacitor C3. The other end of the current-limiting resistor R2 is connected to one end of the power supply filter capacitor C4 at a negative voltage. The other end of the power supply filter capacitor C4 and the other end of the filter capacitor C3 are connected to ground. The anode of the first photodiode PD1 is connected to the cathode of the second photodiode PD2, and the junction is a; junction a is connected to the input terminal of the AC-DC separation module. The same-direction proportional DC amplification module includes: a low-noise amplifier U3, a current-limiting resistor R4, a filter capacitor C12, a power supply filter capacitor C13, a power supply filter capacitor C14, a feedback resistor R6, a resistor R5, and an output resistor R7. The low-noise amplifier U3 includes pins 2, 3, 4, 6, and 7. Pin 2 of the low-noise amplifier U3 is connected to the input terminal of resistor R5, and the output terminal of resistor R5 is grounded. Pin 3 of the low-noise amplifier U3 is connected to the output terminal of current-limiting resistor R4 and the input terminal of filter capacitor C12. Pin 4 of the low-noise amplifier U3 is connected to the negative voltage -5V of power supply filter capacitor C13. Pin 6 of the low-noise amplifier U3 is connected to feedback resistor R6 and output resistor R7. Pin 7 of the low-noise amplifier U3 is connected to the positive voltage +5V of power supply filter capacitor C14. The output terminal of output resistor R7 is connected to the DC signal output terminal DC-Out.

2. Balanced homodyne detector for high-entropy high-speed continuous-variable quantum random number generation according to claim 1, characterized in that The AC / DC separation module includes a DC blocking capacitor C5, a switch SW, an AC blocking inductor L1, and a terminating resistor R3; One end of the switch SW is connected with the input end of the direct current isolation capacitor C5, the other end is connected with the input end of the alternating current isolation inductor L1, the output end of the direct current isolation capacitor C5 is connected with the cascaded radio frequency alternating current amplification module, the output end of the alternating current isolation inductor L1 forms a node b with the input end of the terminal resistance R3, and the node b is connected with the same direction proportional direct current amplification module; the output end of the terminal resistance R3 is grounded.

3. Balanced homodyne detector for high-entropy high-speed continuous-variable quantum random number generation according to claim 1, characterized in that The cascaded radio frequency alternating current amplification module comprises a first radio frequency amplifier U1, a second radio frequency amplifier U2, an alternating current isolation inductor L2, an alternating current isolation inductor L3, a direct current isolation capacitor C6, a direct current isolation capacitor C7, a power filter capacitor C8, a bypass capacitor C9, a power filter capacitor C10 and a bypass capacitor C11. The first radio frequency amplifier U1 comprises a pin 1, a pin 2, a pin 3, a pin 4, a pin 5 and a pin 6; the pin 1 and the pin 2 of the first radio frequency amplifier U1 are commonly connected to the ground, the pin 3 of the first radio frequency amplifier U1 is connected with the output end of the alternating current direct current separation module, the pin 4 of the first radio frequency amplifier U1 is connected with the input end of the power filter capacitor C8 to a positive voltage +5v, the output end of the power filter capacitor C8 is grounded, the pin 5 of the first radio frequency amplifier U1 is connected to the ground, and the pin 6 of the first radio frequency amplifier U1 is connected with the input end of the direct current isolation capacitor C6; the input end of the alternating current isolation inductor L2 is connected with the input end of the direct current isolation capacitor C6; the output end of the alternating current isolation inductor L2 is connected with the input end of the bypass capacitor C9; and the output end of the bypass capacitor C9 is grounded. The second radio frequency amplifier U2 comprises a pin 1, a pin 2, a pin 3, a pin 4, a pin 5 and a pin 6; the pin 1 and the pin 2 of the second radio frequency amplifier U2 are commonly connected to the ground, the pin 3 of the second radio frequency amplifier U2 is connected with the output end of the direct current isolation capacitor C6, the pin 4 of the second radio frequency amplifier U2 is connected with the input end of the power filter capacitor C10 to a positive voltage +5v, the output end of the power filter capacitor C10 is grounded, the pin 5 of the second radio frequency amplifier U2 is connected to the ground, and the pin 6 of the second radio frequency amplifier U2 is connected with the input end of the direct current isolation capacitor C7; the input end of the alternating current isolation inductor L3 is connected with the input end of the direct current isolation capacitor C7, the output end of the alternating current isolation inductor L3 is connected with the input end of the bypass capacitor C11, the output end of the bypass capacitor C11 is grounded, and the output end of the direct current isolation capacitor C7 is connected with an alternating current signal output end AC-Out.

4. Balanced homodyne detector for high-entropy high-speed continuous-variable quantum random number generation according to claim 3, characterized in that The model of the first radio frequency amplifier U1 and the second radio frequency amplifier U2 is a radio frequency amplification chip ABA-52563.

5. The balanced homodyne detector for high-entropy high-speed continuous variable quantum random number generation of claim 1, wherein, The model of the first photoelectric diode PD1 and the second photoelectric diode PD2 is LSIPD-LD50.

6. The balanced homodyne detector for high-entropy high-speed continuous variable quantum random number generation of claim 2, wherein, The model of the switch SW is DSIC01LS-P, which is a single-pole single-throw switch.

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