Fully Electronic Silicon-Based THz Pulse Sources and Detectors

Radiation and detection of ultra-short terahertz pulses with picosecond duration advance a variety of applications, including imaging, spectroscopy, and wireless communication. Silicon-based integrated circuits can replace bulky, expensive femtosecond lasers with low-cost solutions to generate and detect THz pulses with GHz repetition rates. In this paper, we present laser-free fully electronic THz pulse sources and detectors to radiate and detect broadband frequency combs in mm-wave and terahertz regimes. A THz pulse radiator chip based on the reverse recovery of a PIN diode is presented. This chip radiates pulses with a tunable repetition rate that can go up to 10.5 GHz. In the frequency domain, the radiated pulses generate a frequency comb that extends up to 1.1 THz. The spacing between the THz tones can be tuned by changing the repetition rates of the pulses to cover the desired frequency range. In addition to the THz comb source, a broadband frequency comb detector chip is presented. The detector chip uses a tunable frequency comb as a reference to sense the spectrum over a wide bandwidth. Single-tone measurements were performed using the detector from 50 GHz to 280 GHz. The source and detector technologies are used to implement a dual-comb sensing system, in which the mm-wave/THz frequency components of the radiated combs are compressed to a small bandwidth in the RF regime.