Laser Materials for Remote Sensing of Ozone

Space based lidar systems for the remote sensing of Ozone require high-power, high-efficiency lasers operating in the ultraviolet. Diode-pumped solid-state lasers are the primary candidates for this application. Operation in the ultraviolet is typically achieved through two or three frequency conversion steps using nonlinear optical materials. This reduces the efficiency of the laser systems placing very stringent demands on the laser design and the gain media. A promising material for use in lasers for the remote sensing of Ozone is Nd:Y2O3 operating at 914 nm and 948 nm using the 4F3/2 to 4I9/2 transition of the Nd3+ ion. This material offers several advantages over other crystals, including a lower threshold for oscillation of this transition, a high thermal conductivity, and a broad transmission range from 0.23 microns to 8 microns. Recent studies indicate that this material is well suited to Ozone lidar applications provided that crystals of sufficient size and quality are available. This Phase I SBIR project is aimed at developing growth systems to produce high optical quality Y2O3 and at demonstrating proof of concept for scaling of such systems to produce laser rods of sufficient size for use in lasers systems capable of meeting NASA's requirements for Ozone sensing.