Open AccessHigh-sensitivity telecommunication-compatible photoconductive terahertz detection through carrier transit time reduction
Author(s) -
PingKeng Lu,
Deniz Turan,
Mona Jarrahi
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.400380
Subject(s) - terahertz radiation , optoelectronics , materials science , photoconductivity , detector , optics , johnson–nyquist noise , sensitivity (control systems) , photodetector , optical power , carrier lifetime , responsivity , physics , electronic engineering , laser , silicon , engineering
We present a telecommunication-compatible photoconductive terahertz detector realized without using any short-carrier-lifetime photoconductor. By utilizing plasmonic contact electrodes on a thin layer of high-mobility photoconductor, the presented detector offers a short transit time for the majority of the photocarriers in the absence of a short-carrier-lifetime photoconductor. Consequently, high-sensitivity terahertz detection is achieved with a record-high signal-to-noise ratio of 122 dB over a 3.6 THz bandwidth under an optical probe power of 10 mW. To achieve such a high sensitivity, the device geometry is chosen to maintain a high resistance and low Johnson Nyquist noise. This design approach can be widely applied for terahertz detection using various semiconductors and optical wavelengths, without being limited by the availability of short-carrier-lifetime photoconductors.