9412931 Crowe These diodes are now in use around the world for a variety of scientific applications, including, radio astronomy, plasma diagnostics, chemical spectroscopy, atmospheric chemistry, and compact range radar measurements. Previous research has led to the creation of devices that have record performance at frequencies from 1-5 THz. These studies have also indicated that further performance improvements and increased operating frequency are possible. Three graduate students will be involved in this research, two of which will be supported by this grant. Together these students will form a team that strives to fully understand the physics of operation, design and fabrication, and testing and evaluation of THz Schottky diodes. The second technological goal is the research of a novel varactor diode based on a Schottky contact to a two-dimensional electron gas and its use as a millimeter and submillimeter wavelength multiplier. This inherently planar device technology has already demonstrated comparable performance to state-of-the-art planar Schottky devices. Through this research, these novel varactor diodes will be shown to have superior performance to standard Schottky varactors and will thereby become an important source of millimeter and submillimeter wavelength power. ***
