摘要: Classical theories predict the variation of distortions in an electromagnetic wave as it propagates through a turbulent field. Most of these theoretical developments assume idealized turbulence with statistics constant or varying ... 展开 Classical theories predict the variation of distortions in an electromagnetic wave as it propagates through a turbulent field. Most of these theoretical developments assume idealized turbulence with statistics constant or varying smoothly along the propagation path. This assumption, however, is rarely true in real world applications. Furthermore, there is virtually no systematic validation of these theoretical developments, especially when turbulence is variable along the propagation direction. In this work, we use a large database of well-resolved direct numerical simulations with realistic turbulent fields to study the distortions in a laser beam propagating through these fields. Specifically, we look at variance of log-amplitude fluctuations of propagating wavefront and focus on two things. First, we show that the variation in statistics of instantaneous turbulent fields significantly affects the variance of fluctuations in propagating beam. This includes departures from theoretical scaling laws as well as oscillations not explained by existing theories. Second, we investigate the effect of sudden variation in turbulent field by essentially making the turbulent fluctuations zero after a short propagation through turbulence. Here again we observe that the theory fails to predict the distortions in the propagating beam. 收起