This Small Business Innovation Research Phase I project proposes to develop a novel technique for the growth of CdGeAs2 single crystals based on Horizontal Zone Melting (HZM). CdGeAs2 has outstanding optical nonlinear properties, making it the best material for laser harmonic generation and tunable sources in the infrared. However, CdGeAs2 crystals grown by Horizontal Gradient Freeze have substantial optically non-uniform areas, which limits their use. The smaller volume of the melt and the axial symmetry of the thermal field of the HZM technique are expected to produce crystals of improved compositional uniformity.<br/><br/>This project proposes to develop a growth technique based on HZM and apply it to the growth of CdGeAs2. CdGeAs2 single crystals will be grown and their optical transmission will be improved by irradiation with fast electrons. The crystal uniformity will be characterized using x-ray, electrical and optical measurements. Finally, HZM grown CdGeAs2 crystals of uniform composition and quality will be evaluated in an optical parametric oscillator to demonstrate tunable infrared radiation from 4 to 11 um.