Mid-infrared dual-comb spectroscopy with electro-optic modulators

TL;DR

This paper presents a novel mid-infrared dual-comb spectroscopy technique using electro-optic modulators to generate flat, tunable near-infrared combs, enabling rapid, high-resolution molecular spectroscopy in the 3-micron region.

Contribution

It introduces a new method for generating and tuning mid-infrared dual-comb spectra with electro-optic modulators, allowing fast and precise molecular measurements.

Findings

Achieved Doppler-limited absorption spectra within milliseconds

Successfully retrieved precise molecular line parameters

Demonstrated flexible control over comb positions and spacings

Abstract

We demonstrate dual-comb spectroscopy based on difference frequency generation of frequency-agile near-infrared frequency combs, produced with the help of electro-optic modulators. The combs have a remarkably flat intensity distribution and their positions and line spacings can be selected freely by simply dialing a knob. We record, in the 3-micron region, Doppler-limited absorption spectra with resolved comb lines within milliseconds. Precise molecular line parameters are retrieved. Our technique holds promise for fast and sensitive time-resolved studies e.g. of trace gases.