Reference-free dual-comb spectroscopy with inbuilt coherence

TL;DR

This paper introduces a straightforward dual-comb spectroscopy system using two inherently coherent combs generated via seeded parametric down-conversion, enabling long-term coherent averaging through inbuilt coherence and simple post-processing.

Contribution

It presents a novel dual-comb spectroscopy approach with inbuilt coherence, simplifying phase correction and enabling extended coherent averaging.

Findings

Inbuilt coherence allows effective drift compensation.

Long-time coherent averaging is achievable.

Simplifies dual-comb spectroscopy setup.

Abstract

We demonstrate a simple system for dual-comb spectroscopy based on two inherently coherent optical frequency combs generated via seeded parametric down-conversion. The inbuilt coherence is established by making the two combs share a common comb line. We show that the inbuilt coherence makes it possible to use a simple numerical post-processing procedure to compensate for small drifts of the dual-comb interferogram arrival-time and phase. This enables long-time coherent averaging of the interferograms.