Cavity-based mid-IR fiber gas laser pumped by a diode laser

TLDR

Mid‑infrared lasers are rapidly evolving, yet conventional gas lasers are limited by short interaction lengths and bulkiness, and standard fiber cores are opaque at these wavelengths. The authors demonstrate a mid‑IR fiber gas laser that employs cavity feedback. The laser uses acetylene in a high‑performance silica hollow‑core fiber as the gain medium and operates either continuously or synchronously pumped by telecom‑wavelength diode lasers. Lasing was achieved on several 3.1–3.2 µm transitions, and the system can be extended to other molecules up to 5 µm with strong potential for power scaling.

Abstract

Mid-infrared (IR) lasers are currently an area of rapid development, with several competing technologies. In traditional gas lasers, the effective interaction length is limited and the system as a whole is bulky and inflexible, limiting their applications. Standard gain fibers cannot be used in the mid-IR because the glass forming the fiber core is not transparent at these longer wavelengths. In this Letter, we report the demonstration of a mid-IR fiber gas laser using feedback in an optical cavity. The laser uses acetylene gas in a high-performance silica hollow-core fiber as the gain medium, and lases either continuous wave or synchronously pumped when pumped by telecom-wavelength diode lasers. We have demonstrated lasing on a number of transitions in the spectral band of 3.1–3.2 μm. The system could be extended to other selected molecular species to generate output in the spectral band up to 5 μm, and it has excellent potential for power scaling.