Terahertz Detectors for Long Wavelength Multi-Spectral Imaging.

摘要

The purpose of this work was to develop a wavelength tunable detector for Terahertz spectroscopy and imaging. Our approach was to utilize plasmons in the channel of a specially designed field-effect transistor called the grating-gate detector. Grating-gate detectors exhibit narrow-linewidth, broad spectral tunability through application of a gate bias, and no angular dependence in their photoresponse. As such, if suitable sensitivity can be attained, they are viable candidates for Terahertz multi-spectral focal plane arrays. When this work began, grating-gate gate detectors, while having many promising characteristics, had a noise-equivalent power (NEP) of only 10(sup -5) W/(radical)Hz. Over the duration of this project, we have obtained a true NEP of 10(sup -8) W/(radical)Hz and a scaled NEP of 10(sup -9)W/(radical)Hz. The ultimate goal for these detectors is to reach a NEP in the 10(sup -9(yields)-10)W/(radical)Hz range; we have not yet seen a roadblock to continued improvement.