Tunable Terahertz Beat Signal Generation From an InAs/InP Quantum-Dot Mode-Locked Laser Combined With External-Cavity

Abstract

Tunable terahertz beat signal generation is demonstrated by using a C-band InAs/InP quantum-dot (QD) mode-locked laser combined with external cavity of two fiber Bragg gratings (FBGs), where one of the FBGs is tunable in wavelength. Beat signals with ultra-high repetition rates quasi-continuously from 1 to 2.21 THz are observed between the two modes, which are phase-correlated due to intracavity four-wave mixing effect in the QD waveguide.