Phase-front distortion of laser radiation in a turbulent atmosphere

Abstract

The phase-front distortion of laser radiation propagating through the turbulent atmosphere has been measured simultaneously at several wavelengths in the visible using a long-range Mach-Zehnder interferometer with high spatial and temporal resolution (476 nm </= lambda </= 647 nm, 0.5 mm </= Deltar 60 mm Deltat = 0.5 msec, z </= 2 km, C(n) = 1.3 x 10(-7) M(-1/3)). Phase-structure function, transverse coherence length, and arrival-angle fluctuations are interpreted in terms of the meteorological quantities turbulence strength and turbulence structure and inner and outer scale. The investigation covers the strong turbulence regime (scintillation saturation regime) where wave coherence is essentially determined by phase effects. In this regime a breakup of the phase front is found to occur.