532-nm frequency-modulated continuous-wave lidar development

Coherent lidar is seeing a resurgence of interest due to the advent of solid-state narrow-linewidth sources and integrated amplifiers and modulators. At the Geophysical Institute’s Lidar Research Lab (LRL) we are developing a 532 nm frequency-modulated continuous wave (FMCW) breadboard lidar to investigate the capabilities of coherent lidar in the underwater environment. Coherent systems have some advantages over traditional incoherent lidar, including optimal detection, background insensitivity, and the exciting possibility of remotely profiling water current. Coherent lidar can easily achieve millimeter-level range resolution without the need for exotic ultrashort pulse lasers and high-performance timing. Here, we present the modeling, design, and expected performance of the system against submerged diffuse and specular hard targets using established statistical methods (e.g. Goodman, Osche) and oceanographic lidar theory (e.g. Churnside). Current status of the breadboard lidar development will also be reviewed.