Enhanced-output-power broadband terahertz-wave emitter based on slot-antenna-integrated uni-travelling-carrier photodiode

Resonant slot-antenna-integrated uni-travelling-carrier photodiodes were developed for enhancing terahertz (THz)-wave output powers while maintaining relatively broad bandwidths. Their output powers were two to three times larger at their peaks than those of a non-resonant bowtie-antenna-integrated device. The output powers were enhanced at frequencies from 900 GHz to 1.6 THz for a narrow-slot device and from 350 to 850 GHz for a wide-slot device. Typical output powers were 3.5 μW at 1.25 THz and 28 μW at 700 GHz for a photocurrent of 10 mA with a bias voltage of only -0.4 V.