Ultra-broadband quantum cascade laser operating from 1.88 to 3.82 THz

TL;DR

This paper presents a heterogeneously designed terahertz quantum cascade laser with ultra-broadband operation from 1.88 to 3.82 THz, demonstrating significant improvements in spectral bandwidth, power, and comb functionality.

Contribution

It introduces a novel heterogenous active region design that enhances bandwidth, power, and comb operation in terahertz quantum cascade lasers.

Findings

Achieved spectral bandwidth up to 1.94 THz at 3 THz center frequency

Demonstrated frequency comb operation over 1.1 THz bandwidth

Verified comb nature using a self-detected dual-comb setup

Abstract

We report on a heterogeneous active region design for terahertz quantum cascade laser based frequency combs. Dynamic range, spectral bandwidth as well as output power have been significantly improved with respect to previous designs. When operating individually the lasers act as a frequency comb up to a spectral bandwidth of 1.1 THz, while in a dispersed regime a bandwidth up to 1.94 THz at a center frequency of 3 THz can be reached. A self-detected dual-comb setup has been used to verify the frequency comb nature of the lasers.