Spatially multiplexed single-cavity dual-comb laser

TL;DR

This paper introduces a novel method for multiplexing a single-cavity dual-comb laser, achieving high power, low timing jitter, and drift-free operation, enhancing practical applications in ultrafast laser systems.

Contribution

A new multiplexing technique for single-cavity dual-comb lasers that supports noise-correlated modes with improved stability and performance.

Findings

Over 2.4 Watts average power per comb.

Sub-140 fs pulse duration.

Sub-cycle timing jitter of 2.2 fs.

Abstract

Single-cavity dual-comb lasers are a new class of ultrafast lasers which have a wide possible application space including pump-probe sampling, optical ranging, and gas absorption spectroscopy. However, to this date laser cavity multiplexing usually came to the trade-off in laser performance or relative timing noise suppression. We present a new method for multiplexing a single laser cavity to support a pair of noise-correlated modes. These modes share all intracavity components and take a near-common path, but do not overlap on any active elements. We implement the method with an 80-MHz laser delivering more than 2.4 Watts of average power per comb with sub-140 fs pulses. We reach sub-cycle relative timing jitter of 2.2 fs [20 Hz, 100 kHz]. With this new multiplexing technique, we could implement slow feedback on the repetition rate difference {\Delta}frep, enabling this quantity to be drift-free, low-jitter, and adjustable - a key combination for practical applications that was lacking in prior single-cavity dual-comb systems.