A terahertz (THz or T-rays) photomixer consisting of a meander type antenna with integrated nanoelectrodes on a low temperature grown GaAs (LT-GaAs) is demonstrated. The antenna was designed for molecular fingerprinting and sensing applications within a spectral range of 0.3-0.4 THz. A combination of electron beam lithography (EBL) and focused ion beam (FIB) milling was used to fabricate the T-ray emitter. Antenna and nanoelectrodes were fabricated by standard EBL and lift-off steps. Then a 40-nm-wide gap in an active photomixer area separating the nanoelectrodes was milled by a FIB. The integrated nano-contacts with nano-gaps enhance the illuminated light and THz electric fields as well as contribute to a better collection of photo-generated electrons. T-ray emission power from the fabricated photomixer chips were few hundreds of nanowatts at around 0.15 THz and tens of nanowatts in the 0.3-0.4 THz range.

Date Published: 7 December 2013
PDF: 9 pages
Proc. SPIE 8923, Micro/Nano Materials, Devices, and Systems, 892322 (7 December 2013); doi: 10.1117/12.2033746

Published in SPIE Proceedings Vol. 8923:
Micro/Nano Materials, Devices, and Systems
James Friend; H. Hoe Tan, Editor(s)