On-chip Dual-comb based on Quantum Cascade Laser Frequency Combs

TL;DR

This paper demonstrates an integrated on-chip dual-comb source using quantum cascade lasers, enabling compact, high-resolution molecular spectroscopy with full control over comb parameters.

Contribution

It introduces a novel on-chip dual-comb system based on quantum cascade lasers with integrated micro-heaters for precise control, advancing miniaturized spectroscopy technology.

Findings

Achieved full control of dual-comb frequencies.

Demonstrated optical bandwidth of 32 cm$^{-1}$ at 7.52 μm.

Showcased potential for compact dual-comb spectroscopy.

Abstract

Dual-comb spectroscopy is emerging as one of the most appealing applications of mid-infrared frequency combs for high-resolution molecular spectroscopy, as it leverages on the unique coherence properties of frequency combs combined with the high sensitivities achievable by mid-infrared molecular spectroscopy. Here we present an on-chip dual-comb source based on mid-infrared quantum cascade laser frequency combs, where two frequency combs are integrated on a single chip. Control of the combs repetition and offset frequencies is obtained by integrating micro-heaters next to each laser. We show that a full control of the dual-comb system is possible, by measuring a multi-heterodyne beating corresponding to an optical bandwidth of 32 cm$^{-1}$ at a center frequency of 1330 cm$^{-1}$ (7.52 $\mu$m), demonstrating that this device is ideal for compact dual-comb spectroscopy systems.