Compact Ti:Sapphire laser with its Third Harmonic Generation (THG) for an airborne ozone Differential Absorption Lidar (DIAL) transmitter

Abstract

A compact and high-pulse-energy Ti:Sapphire laser with its Third Harmonic Generation (THG) has been developed for an airborne ozone differential absorption lidar (DIAL) to study the distributions and concentrations of the ozone throughout the troposphere. The Ti:Sapphire laser, pumped by a frequency-doubled Nd:YAG laser and seeded by a single mode diode laser, is operated either at 867 nm or at 900 nm with a pulse repetition frequency of 20 Hz. High energy laser pulses (more than 110 mJ/pulse) at 867 nm or 900 nm with a desired beam quality have been achieved and utilized to generate its third harmonic at 289nm or 300nm, which are on-line and off-line wavelengths of an airborne ozone DIAL. After being experimentally compared with Beta-Barium Borate (?-BaB2O4 or BBO) nonlinear crystals, two Lithium Triborate (LBO) crystals (5×5×20 mm3) are selected for the Third Harmonic Generation (THG). In this paper, we report the Ti:Sapphire laser at 900nm and its third harmonic at 300nm. The desired high ultraviolet (UV) output pulse energy is more than 30mJ at 300nm and the energy conversion efficiency from 900nm to 300nm is 30%.