Photonic generation of continuous THz wave using uni-traveling-carrier photodiode

A uni-traveling-carrier photodiode (UTC-PD) is monolithically integrated with a wideband log-periodic toothed antenna for generating millimeter and submillimeter waves at frequencies of up to terahertz range. A module with a quasi-optical output port fabricated for practical use operates up to 1.5 THz and generates an output power of 2.3 /spl mu/W at 1.04 THz with good linearity. The output power level and the operation frequency are records for wideband PD modules operating at 1.55 /spl mu/m. An investigation of the operational characteristics of the UTC-PD reveals that the effective use of the electron-velocity overshoot in the junction depletion layer is important for maximizing the output power in the terahertz range.