Analysis of propagation characteristics of Gaussian beam in weakly compressible flow

Abstract

When the aircraft is flying in the air at high speed, it will compress the surrounding air to form a shock wave layer on the front of aircraft, and the shock wave will gradually turn into turbulence as the distance from the front of the aircraft increases. When the shock wave turns into turbulence, the air is weakly compressible, and the laser will be distorted when it is transmitted in the air, and the intensity will attenuate. In this paper, Gaussian beam is used as the beam source, combined with Rytov theory, the expression of the intensity of Gaussian beam propagation in weakly compressible flow is derived. The results show that air density is an important factor affecting the attenuation of intensity, and the influence of air pressure cannot be ignored. Increasing the beam waist width can resist the attenuation of intensity to a certain extent. It is different from the turbulent atmosphere that the beam attenuation is greater in weakly compressible flows, which must be considered when discuss the attenuation of aerospace communication signals.