Ultra-broadband dual-comb spectroscopy across 1.0-1.9 {\mu}m

TL;DR

This paper demonstrates ultra-broadband dual-comb spectroscopy spanning 1.0 to 1.9 micrometers, capturing a 140-THz spectrum with high precision, enabling detailed molecular analysis across a wide wavelength range.

Contribution

The work introduces a fiber-based dual-comb spectroscopy system achieving an unprecedented 140-THz bandwidth from 1.0 to 1.9 μm with phase-locking and sub-Hz linewidth combs.

Findings

Captured five vibrational-rotational bands of molecules

Achieved spectral accuracy within 2 MHz of previous measurements

Demonstrated simultaneous acquisition of broad spectral data

Abstract

We have carried out dual-comb spectroscopy and observed in a simultaneous acquisition a 140-THz-wide spectrum from 1.0 to 1.9 {\mu}m using two fiber-based frequency combs phase-locked to each other. This ultra-broad wavelength bandwidth is realized by setting the difference between the repetition rates of the two combs to 7.6 Hz using the sub-Hz-linewidth fiber combs. The recorded spectrum contains five vibration-rotation bands of C${_2}$H${_2}$, CH${_4}$, and H${_2}$O at different wavelengths across the whole spectrum. The determined transition frequencies of C${_2}$H${_2}$ agree with those from the previous sub-Doppler resolution measurement of individual lines using CW lasers within 2 MHz.