# Microsecond-resolved electro-optic dual-comb spectroscopy in the 10~12.5 $\\mu$m fingerprint region for radical kinetics

Source: [Microsecond-resolved electro-optic dual-comb spectroscopy in the 10~12.5 $\\mu$m fingerprint region for radical kinetics](<https://www.sota2.com/research/paper/69f2e23455a3c32af89fc7e8>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2026-05-01T05:00:04.848Z

Authors: Pei-Ling Luo, I-Yun Chen

Published: 2026-04-29T10:23:08.000Z

## Abstract

Dual-comb spectroscopy enables broadband, high-resolution measurements with microsecond temporal resolution, but extending this capability to the 10~12.5 $\\mu$m molecular fingerprint region remains technically challenging, particularly for transient radical kinetics. Here, we demonstrate microsecond-resolved dual-comb spectroscopy in this spectral range using electro-optic combs and difference-frequency generation in an orientation-patterned gallium phosphide crystal. Operation near a turning-point quasi-phase-matching condition at approximately 140 $^\\circ$C reduces the wavelength sensitivity of the nonlinear conversion, enabling robust tuning of the idler comb over 83 cm$^{-1}$, corresponding to approximately 1.2 $\\mu$m near 12 $\\mu$m, by adjusting only the signal-comb center wavelength while keeping the pump wavelength and crystal temperature fixed. As a demonstration, we perform high-resolution, microsecond-resolved spectroscopy of transient chlorine monoxide (ClO) near 12 $\\mu$m. Time-resolved dual-comb spectra capture the temporal evolution of ClO produced by the Cl + O$\_3$ reaction with a temporal resolution of 1.5 $\\mu$s, enabling quantitative determination of the ClO formation rate coefficient. These results establish this dual-comb platform as a promising tool for quantitative, microsecond-resolved studies of short-lived radicals, particularly atmospherically relevant halogen oxides.

## Recorded benchmark results

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## Original sources and implementation

[Original paper](<https://arxiv.org/abs/2604.26512>)

[PDF](<https://arxiv.org/pdf/2604.26512.pdf>)