Adaptive real-time dual-comb spectroscopy

TL;DR

This paper introduces a simple, real-time dual-comb spectroscopy method using free-running lasers, eliminating complex control electronics and enabling rapid, broad-spectrum molecular measurements with high resolution.

Contribution

The authors demonstrate a novel adaptive dual-comb spectroscopy technique that operates without phase-lock electronics or complex data processing, simplifying the setup significantly.

Findings

Achieved real-time molecular spectroscopy with free-running lasers.

Eliminated the need for phase-lock electronics in dual-comb systems.

Enabled broad spectral measurements within microseconds.

Abstract

With the advent of laser frequency combs, coherent light sources that offer equally-spaced sharp lines over a broad spectral bandwidth have become available. One decade after revolutionizing optical frequency metrology, frequency combs hold much promise for significant advances in a growing number of applications including molecular spectroscopy. Despite its intriguing potential for the measurement of molecular spectra spanning tens of nanometers within tens of microseconds at Doppler-limited resolution, the development of dual-comb spectroscopy is hindered by the extremely demanding high-bandwidth servo-control conditions of the laser combs. Here we overcome this difficulty. We experimentally demonstrate a straightforward concept of real-time dual-comb spectroscopy, which only uses free-running mode-locked lasers without any phase-lock electronics, a posteriori data-processing, or the need for expertise in frequency metrology. The resulting simplicity and versatility of our new technique of adaptive dual-comb spectroscopy offer a powerful transdisciplinary instrument that may spark off new discoveries in molecular sciences.