Near-infrared dual-comb spectroscopy of CO2 and N2O with a discretized highly nonlinear fiber

TL;DR

This paper presents a novel all-fiber dual-comb spectrometer utilizing a highly nonlinear fiber to efficiently measure absorption profiles of CO2 and N2O, including their collisional broadening effects, with results aligning well with HITRAN data.

Contribution

The work introduces a new fiber design enabling efficient frequency conversion for dual-comb spectroscopy of greenhouse gases.

Findings

Accurate measurement of CO2 and N2O absorption profiles.

Determination of collisional self-broadening coefficients.

Good agreement with HITRAN database.

Abstract

In this paper, we introduce an all-fibered dual-comb spectrometer based on a new design of highly nonlinear fiber to efficiently convert frequency combs from 1.55 micron to 2 micron We show that our spectrometer can be used to measure absorption profiles of rovibrational transitions of CO2 and N2O molecules, and especially their collisional self-broadening coefficients. The results show very good agreement with the HITRAN database and thus further measurements have been performed on a mixture CO2 /N2O to measure the broadening of the CO2 absorption lines resulting from the presence of N2O.