Q-switched laser output control method and laser output device for eliminating seed laser light leakage in coherent wind measuring radar

Abstract

The invention relates to a Q-switched laser output control method for eliminating seed laser light leakage in a coherent wind finding laser and a laser output device so as to eliminate interference ofseed laser light leakage on echo signals of coherent wind finding laser radar. According to the invention, the method and process of an injection locking control system are optimized on the basis ofadopting a seed injection resonant cavity, and the opening time of an acousto-optic Q switch is controlled, so that the seed laser cannot enter a driven annular oscillation cavity within the time interval before the pulse echo signal returns, and the interference of the seed laser light leakage on the echo signals of the coherent wind finding laser radar is eliminated.

Description

technical field [0001] The invention belongs to the technical field of coherent laser wind measuring radar equipment, and in particular relates to a control method and a laser output device for eliminating echo signal interference caused by seed laser light leakage in coherent wind measuring radar. Background technique [0002] Coherent laser wind radar can monitor the three-dimensional wind field of the atmosphere in real time, and has a wide range of applications in the fields of aviation, aerospace, wind power generation and weather forecasting. The use of injection-locked Q-switched pulsed lasers as the laser light source for coherent wind lidar is one of the mainstream methods in the field of coherent wind lidar. [0003] The working mode of the injection-locked Q-switched pulse laser is to inject the seed light with single frequency, narrow linewidth and good beam quality into the driven Q-switched laser resonator for amplification, and the output Q-switched pulse is b...

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Problems solved by technology

[0005] The study found that for the coherent laser wind radar source injected into the seed laser from the diffraction order of the acousto-optic Q-switched crystal, when the Q-switched pulse is emitted, the Q switch is powered on and the pulse output is turned off, and at this time the seed light enters the slave laser Leaked out from the output mirror and emitted into the atmosphere (called "seed laser light leakage"), both the seed laser and the Q pulse laser will be backscattered by atmospheric molecules and participate in the extraction of the interfering wind measurement signal in the heterodyne beat frequency. This causes the signal-to-noise ratio of the echo signal to decrease

And as the detection distance increases, the echo signal of the Q pulse laser gradually weakens, and the reflection signal of the seed laser leaked in the near field is greater than the echo signal of the Q pulse laser, which seriously restricts the improvement of the wind measurement distance of the coherent laser wind radar.

[0006] At present, there have been no relevant reports in this field about the interference of seed laser light leakage on coherent laser wind radar echo signals; and the research and discussion on this problem and the proposed solutions are seldom heard

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