Terahertz Devices

The terahertz (THz) region of the electromagnetic spectrum is under-utilized for lack of convenient sources. In particular, there is no commercial solid-state far-infrared laser at sub-millimeter wavelengths. The objective of this STTR Phase II project isto deliver well-defined far-infrared solid-state laser products based on the p-Ge active medium. Phase I feasibility demonstrations included electrically-controlled wavelength selectors, external semi-confocal cavitites, non-metallic mirrors, an improvedprocess for broad-area high-power ohmic contacts, permanent magnetr assemblies, compact solid-state electronics, and a closed-cycle cooler for the active crystal. Phase II will accomplish the research and development to refine and integrate theseinnovations. Room temperature external cavities and tuning elements will be developed to improve performance and reliability. The configuration of cooler, magnet, and active crystal will be optimized to reduce cooler requirements. Electronics will befurther integrated and miniaturized, and electromagnetic interfernce will be reduced for low-noise applications. Pulse modulation of mode-locked laser emission will be further develeoped for potential free-space telemetry applications. Contacts, mirrors,and magnet assemblies will be further tested and refined. Effort will be directed to exploring potential aerospace uses of the laser with assistance from consultants.