Abstract-Frequency-tunable continuous-wave terahertz sources based on GaAs plasmonic photomixers

Shang-Hua Yang^1,2 and Mona Jarrahi^1,2
 HIDE AFFILIATIONS
1 Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109, USA
2 Electrical Engineering Department, University of California Los Angeles, Los Angeles, California 90095, USA
Appl. Phys. Lett. 107, 131111 (2015); http://dx.doi.org/10.1063/1.4932114

http://scitation.aip.org/content/aip/journal/apl/107/13/10.1063/1.4932114

We present frequency-tunable, continuous-wave terahertz sources based on GaAs plasmonicphotomixers, which offer high terahertz radiation power levels at 50% radiation duty cycle. The use of plasmonic contact electrodes enhances photomixer quantum efficiency while maintaining its ultrafast operation by concentrating a large number of photocarriers in close proximity to the device contact electrodes. Additionally, the relatively high thermal conductivity and high resistivity of GaAs allow operation under high optical pump power levels and long duty cycles without reaching the thermal breakdown limit of the photomixer. We experimentally demonstrate continuous-wave terahertz radiation with a radiation frequency tuning range of more than 2 THz and a record-high radiation power of 17 μW at 1 THz through plasmonicphotomixers fabricated on a low temperature grown GaAs substrate at 50% radiation duty cycle.