A coaxial aerosol lidar system with eye-safe wavelengths

Abstract

The invention relates to a coaxial aerosol laser radar system of a human-eye safe wavelength. An OPO laser device is adopted and then parallel light beams are formed via beam expansion and collimation of a beam expander and then the parallel light beams are emitted into the atmosphere via reflectors. Backward scattered signals of the atmosphere are received by a telescope, and after stray light is restrained through a narrow-band interference filter, a lens is coupled to an optical fiber which then focuses optical signals in an InGaAs APD single-photon counting system and then data acquisition processing is carried out by a data acquisition card and data is stored and realized in a computer. At last, the computer carries out data signal processing and thus atmospherical aerosol parameters are obtained.

Description

technical field [0001] The invention relates to a coaxial aerosol laser radar system with a wavelength safe for human eyes, and belongs to the technical field of pulse laser radar. Background technique [0002] At present, the lidar system used to detect aerosols consists of a laser emitting unit (pulse laser, laser beam expansion and collimation), a laser receiving unit (telescope, interference filter), a signal detection unit, and a data acquisition and processing unit. The laser emitting unit sends a pulse signal into the atmosphere, receives the scattered signal through the telescope, detects it through the detection unit, and processes it through the data acquisition and processing unit to realize the atmospheric aerosol extinction ratio and other parameters. [0003] At present, general laser radars use laser wavelengths of 532nm or 1064nm to measure aerosols. Generally, laser radars have relatively large energy (0.1-1J) and long detection distances, but they cause cer...

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Problems solved by technology

[0004] 1. The detection distance is relatively short, and the pulse energy is at the uJ level, which is far inferior to the lidar developed in the early stage. The lidar with high energy is not safe for the crowd;

[0005] 2. In terms of laser wavelength, the iris of the human eye easily absorbs 1064nm laser, no matter how small the energy is, it is also harmful to human eye safety;

[0006] 3. For places where the aerosol concentration distribution is relatively dense, the penetration ability of 532nm is relatively weak, and the measurement distance is relatively short, while the laser energy of 1064nm is not safe for human eyes

[0007] 4. The longest wavelength band of the current laser radar is 1064nm, and the laser radar in the 1.5um band that is safe for human eyes to detect large particles has not yet been found

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