NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
We report the development and characterization of a passive heterodyne hot electron bolometer (HEB) imager operating at 850 GHz. HEB detectors provide unprecedented sensitivity and spectral resolution at terahertz frequencies covering the frequency range of 0.5-5 THz. Terahertz imagers based on HEB technology have sufficient sensitivity to operate in a passive imaging mode, thus eliminating the need for active illumination. We demonstrated a fully automated passive imaging system based on our HEB technology. The front-end heterodyne detector includes a quasi-optically coupled HEB device in close proximity to an MMIC low-noise IF amplifier. We integrated a compact commercial harmonic multiplier LO source to provide the LO biasing for the HEB detector. Our high spectral resolution terahertz imager has a noise equivalent temperature difference (NEδT) value of 0.4 K and a spatial resolution of about 4 millimeters.
Citation
IEEE Transactions on Microwave Theory and Techniques
Gerecht, E.
, Gu, D.
, You, L.
and Yngvessen, S.
(2008),
A Passive Heterodyne HEB Imager Operating at 850 GHz, IEEE Transactions on Microwave Theory and Techniques, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=32749
(Accessed October 8, 2025)