WGM-Based Photonic Local Oscillators and Modulators

Photonic local oscillators and modulators that include whispering-gallery- mode (WGM) optical resonators have been proposed as power-efficient devices for generating and detecting radiation at frequencies of the order of a terahertz. These devices are intended especially to satisfy anticipated needs for receivers capable of detecting low-power, narrow-band terahertz signals to be used for sensing substances of interest in scientific and military applications. At present, available terahertz- signal detectors are power-inefficient and do not afford the spectral and amplitude resolution needed for detecting such signals.