拉盖尔–高斯光束在小尺度流场内的气动光学效应

Abstract

为研究拉盖尔–高斯(LG)光束在经过由微小凸起造成的流场后的气动光学效应，采用二阶紧致差分对抛物型的复振幅微分方程进行求解，并使用四阶龙格库塔沿光束路径积分。比较了具有不同拓扑荷数的LG光束以及高斯光束在不同马赫数、不同攻角、不同海拔下的Strehl比(SR)以及成像偏移。仿真结果表明，在同样流场中，LG光束的拓扑荷数越大，相位稳定性越好且均优于高斯光束，但振幅稳定性越差，当且仅当径向指数为0，拓扑荷数为1时LG光束优于高斯光束。 To learn about the propagation characteristics of Laguerre-Gaussian (LG) vortex beams through the aero-optical environment formed by a micro-turret, the parabolic beam equations of complex amplitude were solved by second-order compact differences and Runge-Kutta integration was used for integral along the optical path. Strehl ratio (SR) and imaging displacement were calculated at different Mach numbers, different angles of attack, different altitudes and compared among Gaussian beam and LG beams with different topological charges. Simulations show that in the same flow field, the LG beam which has more topological charges, the phase of it has better stability and is always better than that of Gaussian beam, while the amplitude of it has worse stability, only when the radial mode index equals 0 and topological charge equals 1, the amplitude stability of LG beam is better than that of Gaussian beam.