1–2.9-THz Tunable Terahertz Beat Signal Generation Based on InAs/InP Quantum-Dot Mode-Locked Laser

We report on tunable terahertz beat signal generation based on a single-section chirped multiple InAs/InP quantum-dot (QD) mode-locked laser (MLL) combined with a programmable optical filter. It is confirmed that the longitudinal modes during the dual-wavelength emission are phase-locked. Beat signals from 1 to 2.9 THz in multiples of the fundamental repetition rate of the QD MLL are demonstrated between the two extracted modes.