Ultrafast uni-traveling-carrier photodiodes for measurement and sensing systems

Abstract

The uni-traveling-carrier photodiode (UTC-PD) is a newly developed photodiode that utilizes only electrons as the active carriers. This unique feature enables a UTC-PD to achieve excellent high-speed and high-output characteristics simultaneously. Fabricated devices exhibit a record 3-dB bandwidth of 310 GHz, a very-short electrical output pulse of less than 1 ps, high-power millimeter-wave generation at 100 GHz with an output power of over 20 mW, and a sub-millimeter-wave emission at frequencies of up to 800 GHz. The superior capabilities of the UTC-PD for generating wideband millimeter/sub-millimeter waves and very-short electrical pulse signals can innovate various measurement and sensing systems, for instance, millimeter-wave imaging or network analysis. A waveguide-output UTC-PD module with a maximum output power of over 10 mW at 100 GHz is practically important for the photonic-local system in radio telescopes.