Semiconductor terahertz detectors and absorption enhancement using plasmons

As novel applications using terahertz radiation are developed, there is an increased demand for sensitive terahertz detectors. This has led to new approaches for enhancing the response of terahertz detectors. Results were recently reported on the terahertz response of a p-type AlGaAs/GaAs, n-type GaAs/AlGaAs, n-type GaN/AlGaN, and p-type GaSb/GaSb Interfacial Workfunction Internal Photoemission detectors. The use of surface plasmon coupling due to metal grids is one approach discussed here to enhance the performance of these terahertz detectors. Due to the greatly enhanced near fields of the plasmons, the absorption would be increased leading to improved detectors. Results are presented on the enhancement of absorption by plasmon effects in a thin film coupled with a metal grid.