THz Quantum Cascade Laser Frequency Comb based on a Y-coupled Planarized Waveguide

Abstract

Terahertz (THz) quantum cascade lasers (QCLs) can operate as frequency combs [1] and dual combs [2] , making them very appealing for spectroscopy and metrology applications. Recently, Y-split THz QCLs were investigated in the context of tunable single mode operation [3] . Here, we present a Y-coupled double metal planarized waveguide geometry to study broadband phase locking and frequency comb formation.