CN-121977692-A - Spectrometer based on single-pixel single-channel single-photon detector and detection method

CN121977692ACN 121977692 ACN121977692 ACN 121977692ACN-121977692-A

Abstract

The application provides a spectrometer and a detection method based on a single-pixel single-channel single-photon detector, which comprise a dispersion module, a beam path control module, a single-photon detector, a time-to-digital converter, a control system and a control system, wherein the dispersion module is used for stretching a broadband beam to be detected in space, the beam path control module is used for controlling the beam after the spatial stretching to move in one dimension on the surface of the single-photon detector so as to ensure that light with different wavelengths is sequentially irradiated onto the single-photon detector, the single-photon detector is used for detecting components with different wavelengths to realize detection of single photon level and outputting detection signals to the time-to-digital converter, the time-to-digital converter is used for recording and converting photon signal time information into digital signals, and the control system is used for connecting the beam path control module and the time-to-digital converter, establishing single-channel communication with the single-photon detector and controlling the motion state of the beam in the whole detection process, recording photon counts with each wavelength, and further obtaining the corresponding relation between the wavelength and the intensity of the beam to be detected. The application has the advantages of high detection sensitivity, high resolution, simple system and low cost.

Inventors

SHI HAOTIAN
WANG XIAOYUE

Assignees

中国计量大学

Dates

Publication Date: 20260505
Application Date: 20260210

Claims (7)

1. The spectrometer based on the single-pixel single-channel single-photon detector is characterized by comprising a dispersion module, a beam path control module, the single-photon detector, a time-to-digital converter and a control system; The dispersion module is used for spatially widening the broadband light beam to be detected; the beam path control module is connected with the dispersion module and used for controlling the light beam subjected to spatial widening to perform one-dimensional movement on the surface of the single photon detector so as to ensure that light with different wavelengths is sequentially irradiated on the single photon detector; The single photon detector is connected with the beam path control module and is used for detecting one-dimensional moving light beams and components with different wavelengths and outputting detection signals to the time-to-digital converter; The time-to-digital converter is used for recording the time when the single photon detector detects the photon signal, converting the time into a digital signal and feeding the digital signal back to the control system; The control system is connected with the beam path control module and the time-to-digital converter, and establishes single-channel communication connection with the single photon detector, and is used for controlling the motion state of the light beam in the whole detection process and recording photon counts of each wavelength, namely light intensity information.
2. The spectrometer based on the single-pixel single-channel single-photon detector according to claim 1, wherein the dispersion module comprises a prism or a grating, the prism is a powell lens, and the grating is a blazed grating for enhancing the spatial widening effect of the light beam.
3. The single-pixel single-channel single-photon detector based spectrometer of claim 1 wherein the beam path control module comprises a one-dimensional galvanometer or MEMS galvanometer.
4. The single-pixel single-channel single-photon detector-based spectrometer of claim 1 wherein the single-photon detector is a single-pixel avalanche photodiode single-photon detector operating in a continuous detection mode, continuously detecting photons having wavelengths between 400nm and 1100 nm.
5. The spectrometer based on single-pixel single-channel single-photon detector according to claim 1, wherein the control system is an FPGA development board or a host computer.
6. Spectrometer based on single-pixel single-channel single-photon detector according to any of claims 1-5, characterized in that the distance between the single-photon detector and the beam path control module, and the distance between the one-dimensional galvanometer and the dispersion module, is preferably set to 100mm, and the single-photon detector target width is preferably set to 100 μm.
7. The spectrum detection method based on the single-pixel single-channel single-photon detector is characterized by comprising the following steps of: Firstly, the broadband light beam to be measured is spatially widened through a dispersion module, so that light with different wavelengths is separated in physical space; Then, the beam path control module controls the movement of the widened beam in one-dimensional direction, so that each spectrum component in the beam can be ensured to be sequentially irradiated on the single photon detector according to a preset sequence; the single photon detector detects photons in the broadened beam, and transmits detected photon signals to the time-to-digital converter in a single-channel communication mode; Finally, the time-to-digital converter converts the received photon signal time information into a digital signal for subsequent data processing and analysis; In the whole detection process, a control system, a beam path control module, a single photon detector and a time-to-digital converter are used for establishing single-channel communication, controlling the coordination and consistency of the whole spectrum detection process, and accurately recording and processing photon counts corresponding to each wavelength, so that high-resolution spectrum information is obtained.

Description

Spectrometer based on single-pixel single-channel single-photon detector and detection method Technical Field The application belongs to the fields of ultrafast laser and spectrum measurement, and particularly relates to a spectrum detection technology based on a single-pixel single-channel single-photon detector. Background The spectrometer is an important tool for spectrum analysis and is widely applied to the fields of biomedical science, material analysis, quality detection, ultra-fast optics and the like. The detection device of the traditional spectrometer is a linear array CCD, and thousands of pixels are arranged on the one-dimensional scale, so that the light beam after spatial widening can be measured. However, the linear array CCD has low sampling rate due to the large number of pixels, if the sampling rate of the spectrometer needs to be increased, the number of channels needs to be increased, the cost is greatly increased, and the traditional spectrometer cannot realize weak light measurement, so that the sensitivity is low, and the application range of the spectrometer is greatly limited. Currently, single-photon detectors of single pixels, such as avalanche photodiode single-photon detectors, have very mature technology, the time jitter full width at half maximum of the silicon avalanche photodiode single-photon detectors reaches 56ps[Acta Physica Sinica, 69 (7), 074204 (2020), the quantum efficiency reaches 70% [ ACTA PHYSICA SINICA, 67 (22), 221401 (2018) ], the weak light detection of single photons can be realized, the quantum limit is reached, and the size is small and the integration is good. For weak light spectrum detection required in quantum physics experiments, a traditional photoelectric detector, such as a linear array CCD, cannot detect single photon level, and if accumulation measurement is performed, the problems of large environmental noise and thermal noise exist. If a single photon detector array is used, the cost will be greatly increased, and there is also a problem of low sampling rate. For example, patent document CN114166765A discloses a spectrum measurement system based on a single photon detector array, which uses a virtual image phase array and two-dimensional dispersion of reflection diffraction, and uses the single photon detector array to perform detection so as to improve wavelength resolution and expand detection range, but the detection requires the single photon detector array, which is extremely expensive. If multi-channel probing is used, the complexity of the subsequent signal system and control system design is increased. For example, patent document CN116608949a discloses a single photon spectrometer based on optical fiber dispersion, which uses optical fiber as an optical transmission device, and has the advantages that due to group velocity dispersion, light with different wavelengths has different refractive indexes in the optical fiber, light with different wavelengths has different transmission speeds in the optical fiber, and the arrival of the light with different wavelengths to the detector has a sequence. By this temporal separation, the intensities of the different wavelengths are measured. However, for time stretched pulses, only one detector is used to measure the stretched pulses, a means similar to a chopper or other frequency division is required, and the final detector is often a silicon-based single photon detector with a wavelength in the range 400-1000nm, but the bandwidth of the fiber is narrow and the fiber system is greatly affected by temperature. These disadvantages increase the cost and complexity of the spectrometer, and have significant drawbacks in terms of increasing the sampling rate, reducing the cost, enhancing the integration, and achieving high sensitivity detection under low light conditions. Therefore, a new technical solution is needed to solve the above technical problems, and realize high-sensitivity, high-sampling rate, low-cost and high-integration spectrum detection. Disclosure of Invention In order to solve the problems, the application provides a spectrometer based on a single-pixel single-channel single-photon detector, which leads to spatial broadening through a dispersion module, so that different wavelengths are separated in space, and the single-pixel single-channel single-photon detector is used, and the same effect as a linear array or area array detector is achieved by a mechanical scanning mode, so that the spectrometer has the advantages of high detection sensitivity, high resolution, simple system and low cost. The technical scheme of the application is as follows: The application provides a spectrometer based on a single-pixel single-channel single-photon detector, which comprises a dispersion module, a light beam path control module, the single-photon detector, a time-to-digital converter and a control system, wherein: The dispersion module is used for spatially widening the broadband light beam to