Enhanced multichannel dual-comb spectroscopy of complex systems

TL;DR

This paper introduces an advanced multichannel dual-comb spectroscopy method with a photodetector array, enabling high-resolution, broadband spectral analysis of complex atomic systems and revealing new absorption lines in samarium vapor.

Contribution

It presents a novel multichannel dual-comb spectroscopy technique with a photodetector array and RF comb offset, improving spectral coverage and accuracy for complex atomic systems.

Findings

Successful detection of previously unreported samarium absorption lines

Enhanced spectral coverage over a 52nm range

Demonstration of accurate spectral reconstruction with RF offset

Abstract

A multichannel dual-comb spectroscopy (DCS) approach for high-resolution, broadband spectral measurements is presented, demonstrating its effectiveness in studying complex atomic systems. By implementing a photodetector array, we enhance DCS capabilities, addressing the fundamental trade-off between signal-to-noise ratio (SNR) and spectral coverage. To resolve ambiguities in frequency conversion, we introduced a relative offset in the radio frequency (RF) comb teeth, ensuring accurate spectral reconstruction. As a proof of concept, the absorption spectrum of samarium (Sm) vapor is investigated over a 52nm range, and several previously unreported absorption lines are detected. This is a step toward "Spectroscopy 2.0", enabling massively parallel spectroscopic measurements (including those at >100 T magnetic fields) crucial for atomic physics and fundamental interactions research.