High-power dual-comb thin-disk laser oscillator for fast high-resolution spectroscopy

Abstract

Free-running dual-comb systems based on a single laser cavity are an attractive next generation technology for a wide variety of applications. The high average power achievable by dual-comb thin-disk laser (TDL) oscillators make this technology especially attractive for spectroscopy and sensing applications in the molecular fingerprint region enabled by nonlinear frequency conversion. However, the high noise levels of TDL oscillators, e.g., induced by the turbulent water-cooling of the disk, are a severe challenge for spectroscopic applications. In this contribution, we confirm for the first time the suitability of dual-comb TDLs for high-resolution spectroscopy. Based on the novel concept of polarization splitting inside a TDL, our oscillator generates two asynchronous pulse trains of 240-fs pulse duration at 6-W and 8-W average power per pulse train and ∼97-MHz repetition rate at a central wavelength of 1030 nm. In the first detailed noise investigation of such a system, we identify the repetition frequency as the dominant noise term and show that ∼85% of the frequency noise of the comb lines of both pulse trains is correlated (integrated from 200 Hz to 20 kHz). We detect the absorption spectrum of acetylene in free-running operation within a measurement time of 1 millisecond. Being highly suitable for nonlinear frequency conversion, we believe the here presented result is an important step towards simple yet powerful mid-infrared dual-comb systems for high-resolution spectroscopy.

Dual-comb thin-disk oscillator

“…A recently published dual-comb thin-disk oscillator based on polarization splitting 43 delivers similar output parameters and additionally confirms our finding with regard to the importance of fluctuations.…”

Picosecond ultrasonics with a free-running dual-comb laser

“…Compared to our previous solid-state dual-comb demonstration [82], here we demonstrate a significantly performance-improved free-running dual-comb laser oscillator delivering 1.8 W of average power at 80-MHz repetition rate at a pulse duration of 110 fs from each output comb; this corresponds to a peak power enhancement of more than ten times. Although higher average power free-running dual-comb laser oscillators using thin-disk geometry have been demonstrated recently [89,90], here we demonstrate the highest power free-running dual-comb bulk oscillator to date. The bulk laser geometry is highly relevant for practical applications of such lasers as it enables compact and cost-effective optical sensor development.…”

High-power modelocked thin-disk oscillators as potential technology for high-rate material processing

“…It is important to note that although this performance range can also be achieved with amplifier systems (see Figure 1 ), there are several potential advantages of the direct oscillator approach, however keeping in mind that most of these advantages have not yet been explored in detail in applications, since these systems are fairly novel, laboratory-based setups [ 56 ], [ 57 ], [ 58 ], [ 59 ]. Possibly the most relevant advantage is their amplifier-free operation providing a path for robust, compact and low-noise laser systems when developed into industrial-grade systems, which however remains to be demonstrated.…”