Publication Details

Seniutinas, G., Gervinskas, G., Constable, E., Krotkus, A., Molis, G., Valusis, G., Lewis, R. A. & Juodkazis, S. (2013). THz photomixer with a 40-nm-wide nanoelectrode gap on low-temperature grown GaAs. In J. Friend & H. Hoe. Tan (Eds.), Proceedings of SPIE (pp. 892322-1-892322-9). United States: SPIE.


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.



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