All-optical single photon detection feedback operation multiplexing single photon source

Abstract

The invention discloses an all-optical single-photon detection feedback operation multiplexing single-photon source, and belongs to the field of quantum information and quantum optics. The device comprises a pulse laser pumping source, a correlated photon pair light source array, an all-optical readout single-photon detector, an optical signal collector, a spatial multiplexing optical path, a time multiplexing optical path and a single-photon output optical path. The associated photon pair light source array is used for probabilistically generating an idler frequency light array and a signal light array which are associated with each other under the excitation of the pulse laser pumping source by a plurality of associated photon pair light sources; the all-optical readout single-photon detector is used for detecting and feeding back idler frequency optical array signals; the optical signal collector is used for collecting and discriminating the optical signal output by the single-photon detector and generating a corresponding multi-channel modulation voltage signal; the spatial multiplexing optical path is used for coupling multiple paths of signal light to the same optical path; the time multiplexing optical path is used for synthesizing the optical signals of the multiple timestamps into one timestamp through delay operation; and the single-photon output optical path is used for measuring or outputting a final single-photon signal.

Description

Technical Field

[0001] The present invention belongs to the field of quantum information and quantum optics technology, and specifically relates to an expandable all-optical single-photon detection feedback operation multiplexed single-photon source, which is suitable for optical quantum precision measurement applications. Background Art

[0002] A deterministic single-photon source, that is, a light source that emits only one photon deterministically at periodic time intervals, can be used to prepare large-scale photon entangled states, realize large-scale wavecolor sampling, etc. It plays a vital role in optical quantum computing, long-distance quantum communication, and photon precision measurement.

[0003] Based on single-atom or quasi-atom systems, such as single molecules, diamond color centers, semiconductor quantum dots and other systems, single photons can be generated by spontaneous radiation by exciting the equivalent two-level system from the ground state to the excited state. Self-assembled semiconductor quantum dots currently achieve the highest overall performance single-photon source in this type of system. However, such systems usually require complex sample preparation and low-vibration low-temperature optical systems, and need to be integrated into highly matched microcavity coupling to improve the collection efficiency of single photons. The single-photon preparation efficiency is also limited by quantum efficiency, collection coupling efficiency, etc.

[0004] Multiplexing of light sources based on multiple probabilistically generated correlated photon pairs is a technical approach to asymptotically realize a deterministic single-photon source. Common methods for generating correlated photon pair light sources include the spontaneous parametric down-conversion process and the spontaneous four-wave mixing process. Under each laser pumping, the correlated photon pair light source has a certain probability of generating a pair of photons. By detecting one of the modes, it is possible to predict whether a photon exists in the other mode, thereby predicting the preparation of a single photon. Kaneda et al. in the United States achieved an efficiency enhancement of about 9.7 times by multiplexing 40 spontaneous parametric down-conversion light sources in time degrees of freedom. The efficiency of the multiplexed single-photon source reached 66.7%, but due to the use of high pump powers, the purity of the multiplexed single-photon source they obtained was limited by the second-order correlation function. Indicates only Therefore, in order to achieve better comprehensive performance in the future, that is, to simultaneously meet the requirements of high efficiency and high purity of the multiplexed single photon source, it is necessary to improve the efficiency of the multiplexed single photon source as much as possible. At the same time, it is also necessary to ensure that the efficiency of a single correlated photon on the light source Small enough, the most reasonable way is to increase the number of multiplexed light sources N A key technical challenge for future multiplexed single-photon sources is to simultaneously achieve high-efficiency and high-speed single-photon detection feedback in multiple channels.

[0005] At present, superconducting nanowire single-photon detectors have the best performance in terms of detection efficiency, dark count rate, time jitter and other parameters, and can work in the near-infrared band. This detector can distinguish between the absence of photons and at least one photon. In recent years, it has become an indispensable tool in quantum optics. The operation of superconducting single-photon detectors needs to be carried out in a low-temperature environment. In large-scale multiplexing of single-photon sources and optical quantum information experiments, the number of multiplexed light sources N may reach 100 or even more than 1,000, so it is necessary to operate single-photon detectors of multiple channels at the same time. For example, in the experiment of verifying the superiority of optical quantum computing, more than 100 superconducting single-photon detectors need to be operated simultaneously. However, the cooling performance of traditional cryogenic equipment limits the number of superconducting nanowire single-photon detection chips that can be read independently in a single system, and the radio frequency transmission line of the transmission detection signal of the multi-channel superconducting nanowire single-photon detector will introduce a huge heat load. Thermal radiation will introduce the dark count of the single-photon detector to form an erroneous trigger prediction signal; in addition, the transmission speed of electrical signals is slow, and the signal photon needs to be delayed for a longer time to wait for the feedback operation signal, which will introduce additional photon loss. The efficiency of single-photon source is one of the most important indicators in the fields of optical quantum computing, quantum precision measurement, etc. Designing a method for preparing a high-speed detection feedback operation multiplexed single-photon source is an important issue that needs to be urgently solved in the current field of optical quantum technology. Summary of the invention

[0006] In order to solve the problems of low efficiency and poor scalability of single-photon sources, the purpose of the present invention is to provide an all-optical single-photon detection feedback operation multiplexing single-photon source, use an all-optical readout single-photon detector for predictive detection, and adopt a combination of space and time multiplexing to achieve parallel detection and multiplexing operation of multi-channel probabilistically correlated photon sources, solve the problems of low efficiency and slow detection feedback speed of probabilistic light sources, and have scalability.

[0007] In order to achieve the above object, the present invention is implemented by the following technical solutions: The all-optical single-photon detection feedback operation multiplexed single-photon source disclosed in the present invention includes a pulsed laser pump source, a correlated photon pair light source array, an all-optical readout single-photon detector, an optical signal collector, a spatial multiplexing optical path, a temporal multiplexing optical path and a single-photon output optical path. The laser emitted by the pulsed laser pump source excites the correlated photon pair light source array to generate a correlated idler light array and a signal light array. After coupling, the optical arrays are transmitted to the all-optical readout single-photon detector and the spatial multiplexing optical path respectively via a single-mode optical fiber. The all-optical readout single-photon detector detects the single-photon signal of the idler light array and feeds back the classical light signal. The optical signal collector collects and identifies the classical light signal and converts it into an electrical signal, and synchronously transmits it to the spatial multiplexing optical path and the temporal multiplexing optical path for controlling the optical switch in the optical path. When the idler light detector of the correlated photon pair light source responds, the corresponding optical switch in the spatial multiplexing optical path performs polarization flipping or maintenance, so that the single photons in the corresponding spatial path mode can reach the output path through the spatial multiplexing optical path and be transmitted to the temporal multiplexing optical path. The optical switch in the time-multiplexing optical path controls polarization flipping or holding so that single photons in different time modes are merged into the same time mode after passing through different delay optical paths.

[0008] Pulse laser pump source, used to generate high repetition rate pulse laser.

[0009] The correlated photon pair light source array is used for multiple correlated photon pair light sources to probabilistically generate correlated idler light arrays and signal light arrays under the excitation of the pulse laser pump source. After corresponding optical coupling, each path is collected into a single-mode optical fiber.

[0010] All-optical readout single-photon detector is used to detect and feedback idler light array signals.

[0011] The optical signal collector is used to collect and identify the optical signals output by the single-photon detector and generate corresponding multi-channel modulated voltage signals.

[0012] Spatial multiplexing optical path is used to couple multiple signal lights into the same optical path.

[0013] The time multiplexing optical path is used to synthesize optical signals of multiple time stamps into one time stamp through a delay operation.

[0014] The single-photon output optical path is used to measure or output the final single-photon signal, including a polarization beam splitter and a collection coupler.

[0015] Furthermore, the all-optical readout single-photon detector includes a superconducting nanowire detection chip array, a low-temperature photodiode, a low-temperature amplifier array and a low-temperature optical modulation array.

[0016] The superconducting nanowire detection chip array is used to receive and detect the signal of the associated photon pair light source array connected to the superconducting working temperature zone through the single-mode optical fiber and the coupler.

[0017] The low-temperature photodiode is used to receive a pulse laser signal introduced by a pulse laser pump source through a single-mode optical fiber to generate a bias current.

[0018] The cryogenic amplifier array operates in a cryogenic disk in a temperature zone different from the superconducting temperature zone, and is used to amplify the photocurrent signal output by the superconducting nanowire detection chip array.

[0019] The voltage signal generated by the low-temperature photodiode and superconducting nanowire detection chip array is amplified by the low-temperature amplifier array and then transmitted to the low-temperature optical modulation array. The voltage generates an electric field in the waveguide, which changes the refractive index of the waveguide interferometer through the electro-optical effect, thereby changing the port of the waveguide interferometer outputting the optical signal and outputting a feedback optical signal.

[0020] Furthermore, the signal light emitted from the associated photon pair light source in the spatial multiplexing optical path passes through a polarization beam splitter, an optical lens, an electro-optical modulator, and a reflector in sequence, and is finally combined into the same spatial mode by a beam combiner.

[0021] Furthermore, the time multiplexing optical path includes an unequal-arm interferometer and an electro-optical modulator, wherein the unequal-arm interferometer includes a time-delay optical ring, an electro-optical modulator, a reflector, and a beam displacement combiner. The electro-optical modulator controls the polarization of photons so that photons pass through optical paths with different time delays in a deterministic manner, thereby merging optical signals of different time modes into the same time mode.

[0022] Furthermore, the pulse laser pump source is used to generate pump laser pulses and low-temperature diode input optical signals.

[0023] Furthermore, the correlated photon pair light source array includes a correlated photon pair light source, a signal light array and an idler light array, and the correlated photon pair light source is used to probabilistically generate photon pairs with high prediction efficiency.

[0024] Furthermore, the optical signal collector has collection and feedback functions for collecting and identifying the optical signal output by the single-photon detector and generating a corresponding multi-channel modulated voltage signal.

[0025] Furthermore, the single-photon output optical path includes an electro-optic modulator, a polarization beam splitter and a collection coupler, which can ensure that the output photons are of single polarization and are collected into a single-mode optical fiber. Beneficial Effects

[0026] 1. The all-optical single-photon detection feedback operation multiplexed single-photon source disclosed in the present invention adopts superconducting nanowire single-photon detectors for idler light signal detection. Compared with the avalanche photodiode single-photon detectors used previously, it has the characteristics of high efficiency and low dark counts, and the working band can be expanded to the optical communication band and the mid-infrared band, which is suitable for generating communication band multiplexed single-photon sources.

[0027] 2. The all-optical single-photon detection feedback operation multiplexing single-photon source disclosed in the present invention adopts a superconducting nanowire single-photon detector optical reading method. Since there is no need to connect a radio frequency signal transmission line between low temperature and room temperature, it can significantly reduce the thermal load of the single-photon detector, increase the number of superconducting nanowire detection chips that can be expanded in a single refrigerator, and solve the cost and complexity problems of the refrigerator.

[0028] 3. The all-optical single-photon detection feedback operation multiplexed single-photon source disclosed in the present invention uses optical signal transmission, which is faster than radio frequency signal transmission, and has a speed advantage in the preparation of multiplexed single-photon sources that require high-speed and efficient active feedback manipulation.

[0029] 4. The all-optical single-photon detection feedback operation multiplexed single-photon source disclosed in the present invention adopts a scheme that combines spatial multiplexing and temporal multiplexing, which can increase the number of multiplexed correlated photon pair light sources, realize parallel detection and multiplexing operation of multi-channel probabilistic correlated photon sources, and significantly improve the preparation efficiency of multiplexed single-photon sources.

[0030] 5. The all-optical single-photon detection feedback operation multiplexed single-photon source disclosed in the present invention, on the basis of achieving the above-mentioned beneficial effects, can realize the use of all-optical readout superconducting nanowire detectors to realize predictive detection and feedback signal output of multiple correlated photon pairs, and realize the preparation of multiplexed single-photon sources, which can be applied to fields such as optical quantum computing and quantum precision measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of a multiplexed single-photon source for all-optical single-photon detection feedback operation according to an embodiment of the present disclosure; Figure 2 A schematic diagram of a multiplexed single-photon source scheme for all-optical single-photon detection feedback operation according to an embodiment of the present disclosure; Figure 3 is a schematic diagram of a phase modulation waveguide interferometer according to an embodiment of the present disclosure; Among them, 1 is a pulse laser pump source, 2 is a correlated photon pair light source array, 2a is a first correlated photon pair light source, 2b is a second correlated photon pair light source, 2c is a third correlated photon pair light source, 2d is a fourth correlated photon pair light source, 2e is a fifth correlated photon pair light source, 2f is a sixth correlated photon pair light source, 2g is a seventh correlated photon pair light source, 2h is an eighth correlated photon pair light source, 3 is an all-optical readout single photon detector, 310 is a superconducting nanowire detection chip array, 320 is a low-temperature photodiode, 330 is a low-temperature amplifier array, 340 is a low-temperature optical modulation array, 341 is a low-temperature optical modulation array, 342 is a low-temperature optical modulation array, 343 is a low-temperature optical modulation array, 344 is a low-temperature optical modulation array, 345 is a low-temperature optical modulation array, 346 is a low-temperature optical modulation array, 347 is a low-temperature optical modulation array, 348 is a low-temperature optical modulation array, 349 is a low-temperature optical modulation array, 350 is a low-temperature optical modulation array, 351 is a low-temperature optical modulation array, 352 is a low-temperature optical modulation array, 353 is a low-temperature optical modulation array, 354 is a low-temperature optical modulation array, 355 is a low-temperature optical modulation array, 356 is a low-temperature optical modulation array, 357 is a low-temperature optical modulation array, 358 is a low-temperature optical modulation array, 359 is a low-temperature optical modulation array, 360 is a low-temperature optical modulation array, 361 is a low-temperature optical modulation array, 362 is a low-temperature optical modulation array, 363 is a low-temperature optical modulation array, 364 is a 1—first waveguide, 342—second waveguide, 343—waveguide reflector, 344—electrode, 4—idler light array, 4a—first single-mode fiber coupler, 4b—second single-mode fiber coupler, 4c—third single-mode fiber coupler, 4d—fourth single-mode fiber coupler, 4e—fifth single-mode fiber coupler, 4f—sixth single-mode fiber coupler, 4g—seventh single-mode fiber coupler, 4h—eighth single-mode fiber coupler, 5—signal light array, 6—spatial multiplexing optical path, 6a—first polarization beam splitter, 6b—second polarization beam splitter, 6c—third polarization beam splitter, 6d— Fourth polarization beam splitter, 7-time multiplexing optical path, 8-optical signal collector, 9a-first optical lens, 9b-second optical lens, 9c-third optical lens, 9d-fourth optical lens, 10-first optical modulator, 11-second optical modulator, 12-third optical modulator, 13-fourth optical modulator, 14-fifth optical modulator, 15-sixth optical modulator, 16a-first reflector, 16b-second reflector, 16c-third reflector, 16d-fourth reflector, 16e-fifth reflector, 16f-sixth reflector, 17-first Beam combiner, 18—second beam combiner, 19—third beam combiner, 20—seventh optical modulator, 21—first unequal-arm interferometer, 21a—fourth beam combiner, 21b—fifth beam combiner, 21c—first delay optical ring, 22—second unequal-arm interferometer, 22a—sixth beam combiner, 22b—seventh beam combiner, 22c—second delay optical ring, 23—eighth optical modulator, 24—ninth optical modulator, 25—fifth polarization beam splitter, 26—first single-mode fiber output coupler, 27—second single-mode fiber output coupler. DETAILED DESCRIPTION

[0032] The main purpose of the present invention is to solve the problems of low efficiency of single photon source, slow detection feedback speed and poor scalability of multiplexed single photon source. In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0033] In an embodiment, Figure 2As shown, the all-optical single-photon detection feedback operation multiplexed single-photon source disclosed in this embodiment is used to realize the prediction detection and feedback signal output of multiple correlated photon pairs using all-optical readout superconducting nanowire detectors, and realize the preparation of multiplexed single-photon sources, which are applied to fields such as optical quantum computing and quantum precision measurement. The working process of the all-optical single-photon detection feedback operation multiplexed single-photon source preparation scheme is as follows: In this embodiment, a pulsed laser pump source 1 generates periodic laser pulses, which are transmitted to a correlated photon pair light source array 2 for parallel or series pumping. N=8 The spontaneous parametric down-conversion correlated photon pair light sources are represented as the first correlated photon pair light source 2a, the second correlated photon pair light source 2b, the third correlated photon pair light source 2c, the fourth correlated photon pair light source 2d, the fifth correlated photon pair light source 2e, the sixth correlated photon pair light source 2f, the seventh correlated photon pair light source 2g, and the eighth correlated photon pair light source 2h. Optionally, the correlated photon pair light source can be a spontaneous four-wave mixing parametric light source, a quantum dot biexciton luminescence two-photon light source, etc. The quantum state of a single correlated photon pair light source can be expressed in a low-order approximation in the particle number representation as ,in, represents the probability of producing 0 pairs of photons, represents the probability of producing a pair of photons, In order to ensure a good single photon purity, the pump light power is adjusted to .

[0034] The idle light array 4 of the associated photon pair light source array 2 is collected into single-mode optical fibers through the first single-mode optical fiber coupler 4a, the second single-mode optical fiber coupler 4b, the third single-mode optical fiber coupler 4c, the fourth single-mode optical fiber coupler 4d, the fifth single-mode optical fiber coupler 4e, the sixth single-mode optical fiber coupler 4f, the seventh single-mode optical fiber coupler 4g, and the eighth single-mode optical fiber coupler 4h, and is introduced into the all-optical readout single-photon detector 3 through multiple single-mode optical fibers. Optionally, the first single-mode optical fiber coupler 4a can be connected to a fiber beam splitter to further perform beam splitting operations for quasi-photon number resolution detection.

[0035] For the sake of clarity, the accompanying drawings only show the optical path diagram for the case of N=8. It should be noted that it can be further expanded to a larger number.

[0036] In this embodiment, the superconducting nanowire detection chip array 310 in the all-optical readout single-photon detector 3 includes a plurality of superconducting nanowire detection chips, which can efficiently convert incident single-photon signals into electrical signals. The superconducting nanowire detection chip has the characteristics of efficiency greater than 90% and dark count <50 Hz.

[0037] In this embodiment, the low-temperature photodiode 320 generates a bias current after receiving the laser emitted by the pulse laser pump source 1. The bias current and the electrical signal output by the superconducting nanowire detection chip are input to the low-temperature amplifier array 330 for electrical signal amplification. The amplified electrical signal is input to the low-temperature optical modulation array 340, including a phase modulation waveguide interferometer. Figure 3 The phase modulated waveguide interferometer scheme shown in the figure is composed of a first waveguide 341 and a second waveguide 342 coupled to each other, which are coupled to form a 50:50 optical beam splitter, and waveguide reflectors 343 are plated on the two end faces. The input end of the phase modulated waveguide interferometer is connected to a pulsed laser signal, and an electrode 344 is plated on one of the interference arms. When no electrical signal is loaded on the electrode 344, the optical signal input from the first waveguide 341 of the interferometer will return along the original path through initial phase processing. When a voltage is loaded on the electrode 344, the refractive index of the waveguide is changed through the electro-optical effect, and a phase difference is introduced in the interference arm. After that, the interferometer output light will be output from the second waveguide 342, and will be output from the all-optical readout single photon detector 3 to the room temperature environment through the coupled output fiber array. The optical modulation method has the characteristics of short signal rise time and recovery time, large detector self-reset capability, and large detector saturation count rate.

[0038] In this embodiment, the optical signal collector 8 respectively collects the optical signals output by the coupled output optical fiber array at high speed, generates feedback square wave pulses according to the rising edge arrival time, and outputs them through the room temperature RF transmission cable. The optical signal collector 8 can be used for threshold discrimination, that is, only optical signals reaching a specific intensity can be detected and output feedback square wave pulses, thereby reducing the demand for a high extinction ratio of the phase modulation waveguide interferometer and having more experimental robustness.

[0039] In this embodiment, the signal light in the associated photon pair light source array 2 includes 8 paths, which form a signal light array 5 and are transmitted to the spatial multiplexing optical path 6 through free space. The following takes the signal light beams generated by the first associated photon pair light source 2a and the second associated photon pair light source 2b as an example to illustrate the technical solution of the spatial multiplexing optical path 6: the two light beams first pass through the first polarization beam splitter 6a for polarization-dependent beam combining, and then pass through the first optical lens 9a for beam focusing and beam waist position adjustment, so that the light beams have a suitable waist size when incident on the first optical modulator 10, ensuring optical transmittance and polarization extinction ratio. The first optical modulator 10 performs polarization flipping or polarization maintenance operations under the stimulation of the feedback signal introduced by the optical signal collector 8, ensuring that the photons generated by the first associated photon pair light source 2a and the second associated photon pair light source 2b pass through the first reflector 16a and the second reflector 16b and then pass through the first beam combiner 17, and after the polarization operation of the fifth optical modulator 14, they are further reflected by the third reflector 16c and the sixth reflector 16f and then pass through the third beam combiner 19. Similarly, other signal light beams pass through the second polarization beam splitter 6b, the third polarization beam splitter 6c, the fourth polarization beam splitter 6d, the second optical lens 9b, the third optical lens 9c, the fourth optical lens 9d, the second optical modulator 11, the third optical modulator 12, the fourth optical modulator 13, the sixth optical modulator 15, the fourth reflector 16d, the fifth reflector 16e, and the second beam combiner 18, and then converge into a spatial mode and are input into the time multiplexing optical path 7 through the third beam combiner 19.

[0040] In this embodiment, Figure 1 The principle optical path for multiplexing 4 time stamps into 1 time stamp is shown. The optical signal output from the spatial multiplexing optical path 6 first passes through the seventh optical modulator 20 to flip or maintain the polarization of the optical signal, and then is input into the first unequal arm interferometer 21. The first unequal arm interferometer 21 includes a fourth beam combiner 21a, a fifth beam combiner 21b, and a first delay optical ring 21c, which can perform an operation of 1 times the pulse interval optical path, that is, the optical signal passing through the first delay optical ring and the optical signal directly passing through the short arm of the first unequal arm interferometer 21 will be delayed by 1 times the pulse interval optical path. Through the operation of the seventh optical modulator 20, it is possible to switch the photon signal to enter the second unequal arm interferometer 22 after passing through the first optical delay ring 21c or directly through the short arm through the eighth optical modulator 23. The second unequal arm interferometer 22 includes a sixth beam combiner 22a, a seventh beam combiner 22b, and a second delay optical ring 22c, and the second delay optical ring 22c can generate 2 times the pulse interval optical path. Therefore, through the seventh optical modulator 20 and the eighth optical modulator 23, the four adjacent pulse signals can be synthesized into one time pattern after delay.

[0041] In this embodiment, the photons after passing through the time-multiplexed optical path first pass through the ninth optical modulator 24 for polarization flipping or polarization unchanged operation, and pass through the fifth polarization beam splitter 25 to ensure that the final output photon polarization is a single polarization, and are finally collected into the first single-mode optical fiber output coupler 26 and / or the second single-mode optical fiber output coupler 27 to output the multiplexed single photons.

[0042] For the disclosed embodiments, under the condition that all components are ideal, through high-efficiency single-photon detection and fast active feedback switching, in principle, through multiplexing The number of correlated photons increases the efficiency of the light source to , which is much greater than the efficiency of a single correlated photon to generate a light source , and with The multiplexing efficiency can asymptotically reach 100% with the increase of . In this embodiment, in order to reduce the heat load of the detector, low thermal conductivity optical fiber is used for room temperature to low temperature interconnection. These interconnections can not only provide working power for the superconducting nanowire single photon detector, but also transmit the detection signal to the room temperature environment, which can significantly increase the number of detectors that can be placed in a single refrigerator. In addition, optical signal transmission is faster than electrical signal transmission, which can increase the speed of forecast detection feedback and reduce the length of signal photon delay transmission, thereby increasing the forecast efficiency.

[0043] For the disclosed embodiments, the number of multiplexed light sources of the present invention is It is scalable and can significantly increase the number of modes of the prediction detector under the premise of ensuring the stability of the optical path construction, which can meet the needs of preparing multiplexed single-photon sources with higher efficiency and higher purity, thereby meeting the application of high-precision quantum precision measurement. It should be noted that the embodiments and drawings only show the specific implementation of 8 light source spatial multiplexing optical paths and 4 timestamp multiplexing optical paths, and the number of multiplexed light sources is not limited to the embodiments.

[0044] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. All-optical single-photon detection feedback operation multiplexing single-photon source, characterized by: The invention comprises a pulse laser pump source, a correlated photon pair light source array, an all-optical readout single-photon detector, an optical signal collector, a spatial multiplexing optical path, a temporal multiplexing optical path and a single-photon output optical path; the laser emitted by the pulse laser pump source excites the correlated photon pair light source array to generate a correlated idler light array and a signal light array, and after the light arrays are coupled, they are transmitted to the all-optical readout single-photon detector and the spatial multiplexing optical path respectively via a single-mode optical fiber; the all-optical readout single-photon detector detects the single-photon signal of the idler light array and feeds back the classical light signal, and the optical signal collector collects and identifies the classical light. The signal is converted into an electrical signal and synchronously transmitted to the spatial multiplexing optical path and the time multiplexing optical path to control the optical switch in the optical path; when the associated photon responds to the idler light detector of the light source, the corresponding optical switch in the spatial multiplexing optical path performs polarization flipping or holding, so that the single photon in the corresponding spatial path mode can reach the output path through the spatial multiplexing optical path and be transmitted to the time multiplexing optical path; the optical switch in the time multiplexing optical path controls the single photons in different time modes to merge into the same time mode after passing through different delay optical paths through polarization flipping or holding; Pulse laser pump source, used to generate high repetition rate pulse laser; A correlated photon pair light source array, which is used for a plurality of correlated photon pair light sources to probabilistically generate correlated idler light arrays and signal light arrays under the excitation of the pulsed laser pump source, and each path is collected into a single-mode optical fiber after corresponding optical coupling; All-optical readout single-photon detector for detecting and feeding back idler light array signals; An optical signal collector is used to collect and identify the optical signal output by the single-photon detector and generate a corresponding multi-channel modulated voltage signal; A spatial multiplexing optical path is used to couple multiple signal lights into the same optical path; A time multiplexing optical path is used to synthesize optical signals of multiple time stamps into one time stamp through a delay operation; The single-photon output optical path is used to measure or output the final single-photon signal, including a polarization beam splitter and a collection coupler.

2. The all-optical single-photon detection feedback operation multiplexing single-photon source according to claim 1, characterized in that: The all-optical readout single-photon detector comprises a superconducting nanowire detection chip array, a cryogenic photodiode, a cryogenic amplifier array and a cryogenic optical modulation array; The superconducting nanowire detection chip array is used to receive and detect the signal of the associated photon pair light source array connected to the superconducting working temperature zone through the single-mode optical fiber and the coupler; The low-temperature photodiode is used to receive the pulse laser signal introduced by the pulse laser pump source through the single-mode optical fiber to generate a bias current; The cryogenic amplifier array operates in a cryogenic disk in a temperature zone different from the superconducting temperature zone, and is used to amplify the photocurrent signal output by the superconducting nanowire detection chip array; The voltage signal generated by the low-temperature photodiode and superconducting nanowire detection chip array is amplified by the low-temperature amplifier array and then transmitted to the low-temperature optical modulation array. The voltage generates an electric field in the waveguide, which changes the refractive index of the waveguide interferometer through the electro-optical effect, thereby changing the port of the waveguide interferometer outputting the optical signal and outputting a feedback optical signal.

3. The all-optical single-photon detection feedback operation multiplexing single-photon source according to claim 1, characterized in that: The signal light emitted from the associated photon pair light source in the spatial multiplexing optical path passes through a polarization beam splitter, an optical lens, an electro-optical modulator and a reflector in sequence, and is finally combined into the same spatial mode by a beam combiner.

4. The all-optical single-photon detection feedback operation multiplexing single-photon source according to claim 1, characterized in that: The time multiplexing optical path includes an unequal-arm interferometer and an electro-optical modulator; the unequal-arm interferometer includes a time-delay optical ring and a beam displacement combiner; the electro-optical modulator controls the polarization of photons so that photons pass through optical paths with different delays in a deterministic manner, thereby merging optical signals of different time modes into the same time mode.

5. The all-optical single-photon detection feedback operation multiplexing single-photon source according to claim 1, characterized in that: The pulse laser pump source is used to generate pump laser pulses and low-temperature diode input optical signals.

6. The all-optical single-photon detection feedback operation multiplexing single-photon source according to claim 1, characterized in that: The correlated photon pair light source array comprises a correlated photon pair light source, a signal light array and an idler light array. The correlated photon pair light source is used to probabilistically generate photon pairs with high prediction efficiency.

7. The all-optical single-photon detection feedback operation multiplexing single-photon source according to claim 1, characterized in that: The optical signal collector has collection and feedback functions, and is used to collect and identify the optical signal output by the single-photon detector, and generate corresponding multi-channel modulation voltage signals.

8. The all-optical single-photon detection feedback operation multiplexing single-photon source according to claim 1, characterized in that: The single-photon output optical path includes an electro-optic modulator, a polarization beam splitter and a collection coupler, which can ensure that the output photons are single polarized and collected into a single-mode optical fiber.

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