This Small Business Technology Transfer (STTR) Phase II research project will design and develop practical traveling-wave tube (TWT) amplifiers and oscillators at THz frequencies. During Phase II the research team will 1) optimize the design for low noise operation, 2) add a tuned feedback loop to the 0.345 THz TWT so the unit can function as a stand-alone oscillator, 3) based upon the experience gained at 0.345 THz, develop a detailed design for a TWT for higher frequency operation (e.g. 0.65, 0.82, and 1.5 THz where atmospheric absorption by water is at its minimum at THz frequencies), and 4) package a THz TWT for a wide variety of commercial uses. The proposed developments will increase the coherent output power available at frequencies above ~200GHz by orders of magnitude, while dramatically reducing the cost per milliwatt. The work will also provide a path for the realization of the first THz low-noise amplifiers. If successful the results from the proposed research will lead to the availability of signal sources and amplifiers capable of yielding orders of magnitude more coherent power in the THz regime than is currently available. The devices coming out of the effort will lead to THz components and devices that can be used in applications ranging from communications and remote sensing to medical imaging. . Potential end-users include NASA, aerospace companies, telecommunication companies, the security industry, companies engaged in the development of medical imaging systems, and the military
