Time-resolved dual-comb spectroscopy with a single electro-optic modulator

TL;DR

This paper demonstrates a simplified dual-comb spectroscopy system using a single electro-optic modulator, achieving high spectral resolution and long coherence times for time-resolved measurements of transient events.

Contribution

It introduces a novel, simplified dual-comb spectrometer design that maintains high coherence and enables flexible, high-resolution time-resolved spectroscopy without active stabilization.

Findings

Achieved up to 50-s mutual coherence time without active stabilization.

Demonstrated 100-microsecond time resolution in experiments.

Obtained high signal-to-noise ratio enabling precise rovibrational line analysis.

Abstract

Time-resolved near-infrared absorption spectroscopy of single non-repeatable transient events is performed at high spectral resolution with a dual-comb interferometer using a continuous-wave laser followed by a single electro-optic amplitude modulator. By sharing high-speed electrical/optical components, our spectrometer greatly simplifies the implementation of dual-comb spectroscopy and it offers a high mutual coherence time, measured up to 50-s, without any active stabilization system and/or data processing. The time resolution, which can be reconfigured a posteriori, is as short 100 microseconds in our experimental demonstration. For a span of 36 GHz, the mean signal-to-noise ratio of 80, at 100-MHz spectral resolution and 100-microsecond measurement time, enables the precise determination of the parameters of rovibrational lines, including intensity or concentration.