Growth of Nd-Doped Y2O3 Crystals for Space Based Ozone Laser Transmitters

Space-based ultraviolet (UV) and Differential Absorption Lidar (DIAL) systems are required for measurements of ozone and aerosols. Currently, optical parametric oscillator (OPO) and sum frequency mixing (SFM) technologies are used to produce the UV pulses. These systems have low efficiency, are complex and difficult to base on a satellite. Nd:Y2O3 laser systems are efficient at 914 and 948 nm laser generation which after tripling (305 nm and 315 nm, respectively) could produce efficient, reliable and simple systems for space based ozone laser transmittal applications. Nd:Y2O3 crystals of sufficient size and purity are currently unavailable. One of the main problems in growing Y2O3 crystals from the melt is its high melting temperature (2410C). It is intended to adapt the Heat Exchanger Method (HEM) and demonstrate feasibility of Y2O3 crystal growth. A fully-insulated HEM furnace with no moving parts is ideally suited for growth of large crystals at high temperatures. During the proposed six-month program an HEM furnace will be set up (at Crystal Systems's expense) to operate at 2500C and utilize it for Y2O3 crystal growth. Once feasibility of Y2O3 crystal growth is established, larger crystals of Nd:Y2O3 will be grown for laser applications during the Phase II program.