A new Lidar technology using frequency comb light source

Abstract

As the increasing demands of the environmental protection, meteorological monitoring, ecological detection and other fields, lidars are needed to simultaneously measure a variety of atmospheric parameters (especially simultaneous measurement of various pollutants, such as volatile organic solvent VOCs). Multi-wavelength Raman lidar, differential absorption lidar (DIAL) and high spectrum resolution lidar (HSRL) can be implemented these fields. But either technique needs multiple laser sources to meet their requirements. This paper proposes a new lidar based on Frequency Comb Light Source, which can provide multiple frequency components through a single light source for simultaneously measuring various multiple atmospheric parameters. The frequency comb laser light source is used to emit seed light of frequency ωc from the seed laser, and then after passing through the frequency comb laser, a series of equally spaced spectral frequency components are emitted centered on ω_c; then emitted into the atmosphere, and the laser reacts with the atmosphere. The echo signal enters the receiving optical path through the telescope, and is sent through the beam splitter or the discriminator to detect by the detector. Based on different pollutants have different absorption cross sections, similar differential absorption lidar(DIAL), the λ_on and λ_off can be determined. The lidar using the frequency comb light source can be easy designed into a compact structure, which is convenient to carry and maintain. It's also a very advantageous for the lidar miniaturization and industrialization with a wide application prospect.