LABORATORY SIMULATION OF A TURBULENT LAYER - OPTICAL AND IN-SITU CHARACTERIZATION

Up to now only a few numerical or experimental simulations of atmosphe ric turbulent layers have been performed in the laboratory. These are devoted mainly to show the validity of Kolmogorov behavior but are not suitable to implement in an optical bench to test light propagation. Here we present a small size experimental simulation of an optical tur bulent layer. With optical and in situ measurements, we managed to det ermine its characteristics: the mean variance of the refractive-index fluctuations integrated over the thickness of the turbulent flow and l ongitudinal and transverse structure functions of angles of arrival. F rom these measurements we found that the power spectrum of the refract ive index is well fitted by a Von Karman function with an outer scale of 91 mm and an inner scale of 4.7 mm. Moreover, the temporal stationa rity of these parameters indicates the reproducibility of this simulat ed turbulent flow. (C) 1996 Optical Society of America