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arXiv · 1912.03857

Time-stretch infrared spectroscopy

Akira Kawai·Kazuki Hasihmoto·Venkata Ramaiah Badarla·Takayuki Imamura·Takuro Ideguchi
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Abstract

Improving spectral acquisition rate of broadband mid-infrared spectroscopy promises further advancements of molecular science and technology. Unlike the pump-probe spectroscopy that requires repeated measurements with different pump-probe delays, continuous spectroscopy running at a high spectral acquisition rate enables transient measurements of rapidly changing non-repeating phenomena or statistical analysis of a large amount of spectral data acquired within a short time. Recently, Fourier-transform infrared spectrometers (FT-IR) with rapid delay scan mechanisms including dual-comb spectrometers have significantly improved the measurement rate up to ~1 MSpectra/s that is fundamentally limited by the signal-to-noise ratio. Here, we overcome the limit and demonstrate the fastest continuous broadband vibrational spectrometer running at 80 MSpectra/s by implementing wavelength-swept time-stretch spectroscopy technique in the mid-infrared region. Our proof-of-concept experiment of the time-stretch infrared spectroscopy (TS-IR) demonstrates broadband absorption spectroscopy of phenylacetylene from 4.4 to 4.9 {\mu}m (2040-2270 cm-1) at a resolution of 15 nm (7.7 cm-1) with a superior signal-to-noise ratio of 85 without averaging and a shot-to-shot fluctuation of 1.3%.

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Akira Kawai, Kazuki Hasihmoto, Venkata Ramaiah Badarla, Takayuki Imamura, Takuro Ideguchi. 2019-12-09. Time-stretch infrared spectroscopy. https://doi.org/10.1038/s42005-020-00420-3

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