Broadband Terahertz Quantum Cascade Laser Dual‐Comb Sources under Off‐Resonant Microwave Injection

Abstract

Dual-Comb Sources In article number 2100361, Juncheng Cao, Heping Zeng, and Hua Li and co-workers experimentally demonstrate broadband quantum cascade laser dual-comb sources emitting in the terahertz frequency range by employing an off-resonant microwave injection. A numerical analysis based on a rate equation model reveals that the wider lasing bandwidth and a higher degree of phase matching resulted from the off-resonant injection can be the main reasons for the observed broadband dual-comb operation. The demonstrated technique can be further adopted in other laser systems to broaden the spectral bandwidth.