Frequency-agile injection-seeded terahertz-wave parametric generation

Abstract

An injection-seeded terahertz (THz)-wave parametric generator (is-TPG) enables access to low-frequency fingerprints of molecules in the THz frequency region. However, its conventional scan repetition rate (SRR) is limited below 1 Hz. Thus, in this Letter, we propose an electrically controlled tuning system for the is-TPG, which provides high-speed scanning and random hopping agility. We achieved rapid THz frequency scanning on a pulse-by-pulse basis by employing a gain-switched laser diode and a micro-electromechanical system tunable vertical-cavity surface-emitting laser as the pump and seed lasers. A THz spectrum was acquired with a 10 times higher SRR of 10 Hz for the 1.6–3 THz range with a sampling resolution of 4.6 GHz.