TERAHERTZ EMISSION FROM ELECTRIC-FIELD SINGULARITIES IN BIASED SEMICONDUCTORS

We use electric field singularities in biased metal semiconductor micr ostructures to enhance the generation of terahertz (THz) radiation fro m semiconductors. We find that, regardless of the mechanism that is re sponsible for enhanced THz emission near the anode, singular electric fields near sharp anode features will enhance this emission by as much as an order of magnitude. We show scanning THz measurements of severa l of these structures and discuss the physical mechanism responsible f or this enhanced emission. A new family of more efficient terahertz em itters based on these effects can be designed that will improve the dy namic range of THz imaging and spectroscopy systems. (C) 1996 Optical Society of America.