UCLA researchers in the Department of Electrical Engineering have developed a novel tunable and efficient terahertz (THz) plasmon generation on-chip via graphene monolayers.
Generating, confining, and controlling graphene plasmons on optoelectronic chips would be groundbreaking but remains elusive to date. Recently, graphene plasmons have been generated via optical nonlinearity. However, it is still challenging to achieve graphene plasmons in chip-scale integrated photonics and optoelectronics because of the complicated nanofabrication, sensitive free-space calibration, and lack of specific source and detectors.
Researchers led by Professor Chee Wei Wong have developed a novelgraphene heterostructure semiconductor chip, where single THz surface plasmons are generated using ‘C+L’ light sources.The THz frequency and intensity is tunable via external gate voltage and the optical-to-THz conversion is at least an order of magnitude more efficient than prior THz sources. By controlling the optical and electrical conditions, the photon efficiency of the graphene plasmons reaches ~10-4, with a Q factor approaching 60. This innovative platform will lead to chip-scale room-temperature THz sources, switches, modulators, detectors, lasers, polarizers, and sensors based on graphene.
Prototype graphene-based semiconductor chips have been fabricated and extensively tested.
|United States Of America||Issued Patent||10,901,243||01/26/2021||2016-954|
Graphene, terahertz, THz plasmon generator, tunable plasmon, semiconductor chip, room-temperature, switches, modulators, detectors, lasers, polarizers, sensors