Systematic Study of the Growth and Processing of ZnTe and GaP Crytals for THz Detection

Terahertz radiation is an ideal candidate for non-invasive interrogation of concealed objects and substances. As such, there is an increased need for reliable high-quality nonlinear materials for the generation and detection of THz radiation. Zinc telluride (ZnTe) and gallium phosphide (GaP) are the materials of choice for this purpose. However, the performance of these materials varies widely from vendor to vendor, and sometimes, even from a single vendor. We propose to systematically study the growth and processing of ZnTe and the processing of GaP in an effort to determine the necessary procedures to reliably produce high quality crystals. We will fabricate terahertz sensors based on ZnTe and GaP crystals and thin films. We have extensive experience and expertise in producing ZnTe crystals of extremely high purity and crystallographic perfection. Also, Brimrose is one of the very few suppliers in the world capable of producing acousto-optic devices using GaP crystals and thin films. The material that is developed during Phase 1 will be used to fabricate single-element terahertz detectors. Testing will be performed at various frequency bands and the results will be used to optimize the growth and processing of the ZnTe crystals and the processing of the GaP crystals.