Abstract

Short-wavelength (1-μm) solid state coherent Nd:YAG lidars offer promise for many atmospheric lidar uses. In this paper, the criteria for the optical design for a short-wavelength coherent lidar is discussed based on a numerical simulation including the effects of atmospheric turbulence and the use of heterodyne detector array. Lidar return signals were simulated using an atmospheric backscatter model consisting of randomly distributed point scatterers. The electric field at the telescope and detector surface was calculated using wave propagation theory. The heterodyne detection efficiency and statistics of the detected signal were calculated as a function of range using the simulated speckle pattern at the detector. The speckle averaging effect with the use of a detector array was also evaluated. The optimal design of the lidar optics is discussed using these results, and a qualitative consideration of the effect of atmospheric turbulence is covered. Preliminary calculations indicate that the transverse coherent speckle cell is rather small (1-10 cm) at the shorter wavelength thus limiting the utility of a large telescope area.

© 1989 Optical Society of America