Development of a novel laser system for the CZMIL Lidar

摘要

The Coastal Zone Mapping and Imaging Lidar (CZMIL) system' aims to expand bathymetric lidar performance inshallow water conditions, where high spatial and temporal data resolutions are required. This must be achieved withoutsacrificing performance in deep water. Very high frequency data collection (as high as 70KHz) utilizing a hybrid flash-point lidar approach is utilized, which places high demands on the transmitted laser beam, namely high pulse power withshort duration with very high fidelity beam characteristics. To meet these requirements, we have developed a compact,high-power, short pulse length, high repetition rate laser with beam quality acceptable for use with the hybrid lidarapproach employed in CZMIL. The short pulse length is achieved using a CW-pumped Q-switched oscillator, and therequired power is achieved by using multiple amplifiers employing fiber coupled, CW end-pumped Nd:YVO_4crystalsprior to doubling the 1064 nm beam. The resulting output power is ~ 30W at 10 kHz with a pulse length of < 2.5 nsFWHM at 532 nm and ~ 20W of residual power at 1064 nm.