Highly sensitive detector for submillimeter wavelength range

A highly sensitive detector of submillimeter wavelength radiation is reported. The detector consists of a semiconductor quantum dot (QD) and a metallic single-electron transistor (SET). The SET detects change in the potential distribution induced by photon absorption within the QD. We have fabricated and studied this detector at wavelengths longer than 200μm. High sensitivity, ∼10−20W∕Hz in terms of noise equivalent power, is found. Further optimization of the detector design is suggested.