Development Of CdMgTe and CdMgSe For Optical Switching Applications

Presently, there is an increase in the need for materials that exhibit strong nonlinear absorption materials for various military applications. In addition to the non-linear optical properties, materials with the following characteristics are desired: variable bandgap, a cut-on wavelength of 0.4 through 1.4um, and a linear transmission greater than 98 percent from the visible (0.4um) through the NIR/SWIR (0.65 through 3um). CdTe is a material with wide range of applications due to its broad transmission range extending from the near IR to the long wave infrared (LWIR) wavelengths. Its ternary modification Cd1-xMgxTe has a bandgap that extends into the visible range, thereby increasing its range of applications. Recently, in collaboration with researchers at the Air Force Research Laboratory at Wright Patterson Air Force Base, we have successfully fabricated high quality single crystals of Cd0.65Mg0.35Te. We completely characterized the linear and nonlinear optical properties of the newly developed material. It has also been shown that the CdSe system can also be utilized for its non-linear optical properties. We propose to investigate the Cd1-xMgxTe and Cd1-xMgxSe material systems for their usefulness in optical switching applications. The objective of this work will be to develop crystals of very high crystallographic quality that exhibit high transmission and a straight band edge. We will perform an intensive investigation and optimization of material purification and crystal growth BENEFIT: Presently, numerous military and commercial system utilize the mid-wave infrared (MWIR) spectral region for target detection. Unfortunately, a significant amount of spectral information is oftentimes lost because of weather or other environmental conditions. As a result, many systems are utilizing the visible (VIS) to the shortwave infrared (SWIR) spectral regions. This has lead to an increase in the need for materials that can provide filtering across multiple broad wavelength regions and have the ability to filter out unwanted information. The materials proposed in this research can be engineered to meet these requirements. Applications include optical limiting, eye and sensor protection, optical pulse shaping, information processing, and laser mode locking.