Axicons for improved lidar performance

Axicon spatial coherence filtering is presented as a method to improve underwater optical ranging. In underwater environments, light detection and ranging (lidar) is often limited by scattering from particulate matter. Previous work suggests that scattered light and object-reflected light have different spatial phase distributions. This work exploits this difference in spatial phase, using an axicon to optically separate light with different degrees of spatial coherence. The performance of the lidar system with and without the axicon filter is compared. Axicon spatial coherence filtering demonstrates the ability to suppress multipath backscatter and forward scatter, leading to improvements in range accuracy