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arXiv · 2604.11622

Long-wave infrared Fourier transform spectroscopy with enhanced and scalable sensitivity

Sergey Vasilyev·Roderik Krebbers·Dmitrii Konnov·Mathieu Walsh·Igor Moskalev·Mike Mirov·Andrey Muraviev·Jerome Genest·Konstantin Vodopyanov·Simona M. Cristescu
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Abstract

We report a broadband long-wave infrared Fourier transform spectrometer with sensitivity exceeding that of previously reported direct-detection implementations. The system combines dual-comb spectroscopy with electro-optic sampling, multi-channel parallel near-infrared detection using InGaAs photodiodes, and real-time GPU-based computational corrections of multiple spectroscopy signals. Detection limits of 0.3 ppb for NH$_{3}$ and 2 ppb for C$_{2}$H$_{4}$ are achieved in 500 s, corresponding to 20x and 40x sensitivity improvements over earlier LWIR demonstrations, while maintaining high 0.0027 cm$^{-1}$ spectral resolution and broad spectral coverage. The architecture supports scalable sensitivity through increased detector count and enables rapid multispecies analysis of complex gas mixtures.

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Sergey Vasilyev, Roderik Krebbers, Dmitrii Konnov, Mathieu Walsh, Igor Moskalev, Mike Mirov, Andrey Muraviev, Jerome Genest, Konstantin Vodopyanov, Simona M. Cristescu. 2026-04-13. Long-wave infrared Fourier transform spectroscopy with enhanced and scalable sensitivity. https://arxiv.org/abs/2604.11622

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