Abstract

A high power (200 mJ/pulse), Q-switched 2.1 μm Ho:YAG Direct-Detection Lidar system has been developed for the eye-safe remote detection of atmospheric aerosols and upper level atmospheric density profiles. While previous Ho Lidar systems have been used for such studies, they have been limited in output power to ~10 mJ/pulse.¹ Our current Lidar study is directed toward the development of a high- power Ho:YAG laser and its use in an eye-safe Lidar system for long- range atmospheric sensing. During the course of these studies, we have made detailed wavelength and temporal characteristics of the output of the high power Ho:YAG laser source and, in particular, the influence of these parameters on the returned Lidar signal. We have found that the temporal variability and wavelength changes within the Ho laser output pulse can significantly alter the absorption (attenuation) of the Lidar beam, and influence the Lidar signal measured. This is primarily due to changes within the pulse of the spectral (wavelength) characteristics, and the resultant overlap of the laser spectrum with absorption lines of water vapor in the atmosphere.

© 1993 Optical Society of America