Lyke Stephen D, Voelz David G, Roggemann Michael C
Department of Electrical and Computer Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, USA.
Appl Opt. 2009 Nov 20;48(33):6511-27. doi: 10.1364/AO.48.006511.
The probability density function (PDF) of aperture-averaged irradiance fluctuations is calculated from wave-optics simulations of a laser after propagating through atmospheric turbulence to investigate the evolution of the distribution as the aperture diameter is increased. The simulation data distribution is compared to theoretical gamma-gamma and lognormal PDF models under a variety of scintillation regimes from weak to strong. Results show that under weak scintillation conditions both the gamma-gamma and lognormal PDF models provide a good fit to the simulation data for all aperture sizes studied. Our results indicate that in moderate scintillation the gamma-gamma PDF provides a better fit to the simulation data than the lognormal PDF for all aperture sizes studied. In the strong scintillation regime, the simulation data distribution is gamma gamma for aperture sizes much smaller than the coherence radius rho0 and lognormal for aperture sizes on the order of rho0 and larger. Examples of how these results affect the bit-error rate of an on-off keyed free space optical communication link are presented.
通过对激光在大气湍流中传播后的孔径平均辐照度起伏的概率密度函数（PDF）进行波动光学模拟，以研究随着孔径直径增加分布的演变。在从弱到强的各种闪烁条件下，将模拟数据分布与理论伽马 - 伽马和对数正态PDF模型进行比较。结果表明，在弱闪烁条件下，对于所有研究的孔径尺寸，伽马 - 伽马和对数正态PDF模型都能很好地拟合模拟数据。我们的结果表明，在中等闪烁条件下，对于所有研究的孔径尺寸，伽马 - 伽马PDF比对数正态PDF能更好地拟合模拟数据。在强闪烁条件下，对于孔径尺寸远小于相干半径ρ0的情况，模拟数据分布为伽马 - 伽马分布，而对于孔径尺寸约为ρ0及更大的情况，模拟数据分布为对数正态分布。文中给出了这些结果如何影响开关键控自由空间光通信链路误码率的示例。
