Frequency locking system of multi-longitudinal-mode high-spectral-resolution laser radar interferometer

Abstract

The invention discloses a frequency locking system of a multi-longitudinal-mode high-spectral-resolution laser radar interferometer. The frequency locking system comprises a multi-longitudinal-mode laser, a half-wave plate, a polarization splitting prism, an acousto-optic modulation module, a spectrum frequency discrimination interferometer, a converging lens, a photoelectric detector, a peak holding circuit and a proportional-integral-differential servo control module, multi-longitudinal-mode pulse laser output by the multi-longitudinal-mode laser passes through the half-wave plate and the polarization splitting prism and then is split to obtain a low-power light beam. The low-power light speed is subjected to frequency shift by the acousto-optic modulation module and then enters the spectrum frequency discrimination interferometer, and the emitted light passes through the converging lens and then is received by the photoelectric detector; and after an electric signal output by the photoelectric detector is transmitted to the peak holding circuit to be processed, the electric signal is output to the proportional-integral-differential servo control module, and a tuning voltage is output to act on the spectrum frequency discrimination interferometer to achieve resonant frequency locking. According to the invention, the requirement of the multi-longitudinal-mode HSRL on the frequency stability of the spectrum frequency discrimination interferometer can be met.

Description

technical field [0001] The invention belongs to the technical field of atmospheric laser radar, in particular to a multi-longitudinal-mode high-spectral resolution laser radar interferometer frequency locking system based on a peak hold circuit. Background technique [0002] High Spectral Resolution Liar (High Spectral Resolution Liar, HSRL) is currently one of the most accurate atmospheric aerosol detection systems, and its advantage lies in the use of filters with high spectral resolution to detect atmospheric The aerosol meter scattering signal is separated from the atmospheric molecule Rayleigh scattering signal, so that the backscattering coefficient and extinction coefficient of the aerosol can be accurately inverted. [0003] In this context, considering the poor adaptability to the environment and the bulky factors of the single longitudinal mode laser used in HSRL, the research on a new HSRL system using multi-longitudinal mode lasers is ongoing. The principle of m...

AI Technical Summary

Problems solved by technology

Although this method can achieve long-term frequency stability, the slow-response temperature adjustment method is destined to have poor short-term stability and requires extremely high temperature accuracy. Therefore, a new frequency-locking method is required to make all longitudinal modes The atmospheric echo signal strictly matches the frequency discrimination curve of the device

However, the multi-longitudinal mode laser in the multi-longitudinal mode HSRL has a simple structure and directly outputs pulsed laser light from the resonator, so the conventional continuous laser frequency locking method is no longer applicable in this system

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