Tunable Teraherz Detector using Plasmons

In order to tunably detect the frequency of electromagnetic radiation in the terahertz band, a grating-gated transistor exploiting plasmon resonances in a two-dimensional electron gas (2-DEG) has been fabricated. Plasmons are collective excitations of electrons within a metal or semi-conductor whose resonant frequency can be tuned by modulating the electron density. When the plasmon resonance overlaps with the frequency of incident terahertz radiation, conduction electrons are excited resonantly, producing an enhanced signal between source and drain. The grating-gate of this detector thus allows for the electronic tuning of the plasmon resonance, and provides the possibility of a tunable detector operating at terahertz frequencies. With this device we hope to advance a number of scientific and technological application as well as aid in the research and development of new, more promising, applications.