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arXiv · 2405.09313

Vortex-comb spectroscopy

Santeri Larnimaa·Markku Vainio
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Abstract

We propose a new Fourier-transform spectroscopy technique based on the rotational Doppler effect. The technique offers an application for optical vortex frequency combs, where each frequency component carries a unique amount of orbital angular momentum (OAM). Here, we emulate a vortex comb using a tunable single frequency laser and a collection of spiral phase plates, generating up to eleven distinct OAM modes. Unlike in traditional Fourier-transform spectroscopy based on the Michelson interferometer (linear Doppler effect), the spectral resolution of vortex-comb spectroscopy is not limited by the mechanical scan distance of the instrument but only by the measurement time. Although the spectrometer requires just one free-running frequency comb, the down-conversion scheme resembles dual-comb spectroscopy, leading to fast mode-resolved measurements.

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Santeri Larnimaa, Markku Vainio. 2024-05-15. Vortex-comb spectroscopy. https://doi.org/10.1063/5.0220119

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