Abstract: Disclosed in the present application is a method for fitting spontaneous emission noise of a lidar system or an optical fiber sensing system. The method includes: providing a trigger collection signal by a signal source; triggering, based on the trigger collection signal, a co-located transceiver module and a distributed transceiver module to perform synchronous detection on a detection target; receiving co-located data and distributed data returned by the detection target; subtracting local noise from the co-located data and the distributed data, respectively; selecting a linear interval to normalize the co-located data; performing subtraction operation on the normalized co-located data and the distributed data to obtain spontaneous emission noise; and fitting the spontaneous emission noise by a function.

Abstract: A single-photon Raman optical frequency comb source is provided, including: a light source assembly, a filtering mechanism, at least three electro-optical modulators, a wavelength division multiplexer and a single photon generating mechanism. The light source assembly is configured to generate a Raman scattering light. The filtering mechanism is configured to pass a light having a specific wavelength, to filter the Raman scattering light and obtain at least three Raman scattering spectral lines. Each electro-optical modulator is configured to modulate a frequency of one of the Raman scattering spectrum lines in one-to-one correspondence, so as to cause a frequency shift of the Raman scattering spectrum line. The wavelength division multiplexer is configured to multiplex all modulated Raman scattering spectral lines and output a Raman optical frequency comb. The single photon generating mechanism is configured to adjust the Raman optical frequency comb to obtain a single-photon Raman optical frequency comb.

Abstract: A single-photon Raman optical frequency comb source is provided, including: a light source assembly, a filtering mechanism, at least three electro-optical modulators, a wavelength division multiplexer and a single photon generating mechanism. The light source assembly is configured to generate a Raman scattering light. The filtering mechanism is configured to pass a light having a specific wavelength, to filter the Raman scattering light and obtain at least three Raman scattering spectral lines. Each electro-optical modulator is configured to modulate a frequency of one of the Raman scattering spectrum lines in one-to-one correspondence, so as to cause a frequency shift of the Raman scattering spectrum line. The wavelength division multiplexer is configured to multiplex all modulated Raman scattering spectral lines and output a Raman optical frequency comb. The single photon generating mechanism is configured to adjust the Raman optical frequency comb to obtain a single-photon Raman optical frequency comb.

Abstract: A dispersion gating-based atmospheric composition measurement laser radar. The atmospheric composition measurement laser radar stretches a femtosecond laser into a broad pulse laser in a time domain by means of dispersion. A femtosecond spectrum is mapped into the broadened laser pulse due to the group velocity dispersion, and then is subjected to time domain gating by means of an intensity modulator (22, 26) for completing the selection of a laser of a preset wavelength. The laser wavelength scanning is achieved by adjusting the delay of an electrical drive signal of the intensity modulator (22, 26). An absorption spectrum of a specific atmospheric composition is obtained by means of laser wavelength scanning so as to measure the concentration of the atmospheric gas composition. The atmospheric composition measurement laser radar can precisely perform free gating on the wavelength where the laser emits, and has high precision in selecting the wavelength.