Average Spreading of Apertured Laser Beams With Beam Distortions In Non-Kolmogorov Turbulence

Abstract

RMS beam width of an apertured laser beam with beam distortions in non-Kolmogorov turbulence is derived with the help of statistical optics methods and extended Huygens-Fresnel principle. Variations of the beam width of an apertured beam with amplitude modulations and phase fluctuations propagating in non-Kolmogorov turbulence are studied in detail. Numerical examples reveal that the beam width mainly depends on the phase fluctuations and the truncations as well as the exponent value, the inner- and outer-scale parameters of the non-Kolmogorov turbulence. It is shown that phase fluctuations can vary the spreading, weaken the optimum truncation effects, and suppress the dependence of spreading on the inner- and outer-scale parameters. It is interesting to find that the effects of the phase fluctuations are negligible as long as the phase fluctuations are controlled under a certain level, i.e., a > 0.03 for the situation considered in the paper. Thus, there exists a phase fluctuation tolerance, which is meaningful for practical applications.