温度场起伏导致空气折射率的起伏,风速的变化影响湍流的动态特性,从而形成光学湍流效应,对大气激光传输产生影响。研制了一种用于研究激光大气传输效应的Herriott长光程大气湍流发生装置,此装置能模拟出温度差范围为10~200℃,风速范围为0~5.8 m/s以及光程为1~100 m的随机大气湍流。分析并测量了在不同温度、风速参数下该装置对激光传输的光束质量影响。实验结果表明,该大气湍流发生装置的性能指标与实际大气湍流性能较为接近,且具有温度范围宽、光程可调、重复性好、准确度高等优点,能够满足大气传输湍流效应的实验要求。
Random variation in temperature field causes refractive index fluctuation in the atmosphere. Wind velocity affects atmosphere turbulence dynamic characteristic. Thus, it forms optical turbulence effects and influences atmospheric laser transmission. Based on this principle, a modified Herriott type of long-optical-path atmospheric turbulence simulator for studies of atmospheric propagation characteristics is proposed. It can simulate the temperature difference (AT) ranging with 10-200℃, wind velocity with 0-5.8 m/s and optical path with 1-100 m for the random atmospheric turbulence. Measurement and analysis of the laser propagation beam quality influence at different AT and wind speeds are completed. Experimental results reveal that the performance of this simulator is almost identical with actual situation. It possesses wide ΔT, optional optical path, good repeatability, highly precise, etc. Therefore, it meets the needs of atmospheric turbulence effect experiment.