Speckle reduction for LIDAR using optical phase conjugation

Summary form only given. Speckle can be a major noise source for LIDAR systems that use topographic backscatter. Averaging and other linear optical techniques can improve the signal-to-noise (S/N) ratio, but at the expense of some other system attribute, such as acquisition time. Optical phase conjugation is not normally considered to be effective in reducing the effects of speckle because only a fraction of the wavefront information content can be reversed. In our work, however, we have found that optical phase conjugation can be used to improve the S/N ratio for LIDAR return signals.