Development of Novel, Band-Gap Engineered Photorefractive Semiconductors CdMnTe:V For Real Time Optical Processing

During this project, we have developed and produced application quality photorefractive Cd(1-x)Mn(x)Te:V crystals with compositions x= 0.15, 0.45, and 0.60. These crystals are useful for applications in the wavelength range of 0.7 to 1.3mm. These crystals were obtained through the following material processing steps: (1) extensive purification of the starting elements (cadmium, manganese and tellurium) and purification if the compound (Cd(1-x)Mn(x)Te); (2) crystal growth from the melt under controlled conditions of heat and mass transfers; and (3) in situ annealing of the crystals after growth. The optimal temperature profile required to produce a favorable growth interface and minimal stress for crystals grown by the Bridgman- Stockbarger method was determined. From computational models, the temperature distribution within the solid and melt in the growth ampoule was calculated and used to construct an improved experimental system for growth of high quality Cd(1-x)Mn(x)Te:V single crystals.