Abstract
This paper proposes a new method for the ΔK lidar for atmospheric temperature measurement. The principle of the temperature measurement consists of Bragg diffraction of the laser beam by an acoustic wave and the temperature dependence of the speed of sound. As the acoustic frequency that satisfies the Bragg condition with one laser frequency is approximately THz order, the ΔK lidar usually uses differential frequency of two laser systems. In this paper, we plume making use of longitudinal modc spacing generated from only one laser oscillator instead of the differential frequency generated from two single-mode laser oscillators. This method can reduce the influence of frequency instability between two single-mode laser frequencies and the ΔK lidar system is simplified. We successfully conducted temperature-measurement experiments for the ΔK lidar system with the longitudinal multi-mode spectrum of a He-Ne laser in a cylindrical tube and in open space.
