9501330 Ruderman This Small Business Innovation Research Phase II project addresses the need for a process to grow large Zinc-Germanium-Phosphorous (Zn-Ge-P) single crystals of high optical quality and low absorption in the 1 to 3 micron optical region, at low cost. The research objectives include: (1) measuring phase equilibria in the Zn-Ge-P system; (2) extending understanding of the defect structures in these crystals; (3) determining the role of important impurities; (4) developing a new synthesis and crystal growth process; (5) annealing studies of grown crystals to decrease optical absorption; and (6) extensive characterization of grown crystals. These Zn-Ge-P crystal with improved optical transmission and crystal quality will provide efficient generation of tunable laser radiation from 2.5 to 12 microns. Potential applications include remote detection of contaminants, defense uses in laser jamming and warning systems and enhanced spectral analysis techniques for chemical analysis.