Emission beyond 4 {\mu}m and mid-infrared lasing in a dysprosium-doped indium fluoride (InF3) fiber

TL;DR

This paper demonstrates the first mid-infrared laser emission beyond 4 μm in a dysprosium-doped indium fluoride fiber, showcasing extended emission wavelength and improved efficiency over traditional fluoride fibers.

Contribution

It introduces indium fluoride fiber as a new host for dysprosium doping, enabling emission beyond 4 μm and the first laser at 3 μm in this material, with reduced multiphonon effects.

Findings

Achieved broad emission around 4.3 μm from dysprosium-doped InF3 fiber.

Demonstrated the first laser emission at 3 μm in InF3 fiber.

Reduced multiphonon effects suggest higher efficiency and longer wavelength potential.

Abstract

Optical emission from rare-earth-doped fluoride fibers has thus far been limited to less than 4 {\mu}m. We extend emission beyond this limit by employing an indium fluoride (InF3) glass fiber as the host, which exhibits an increased infrared transparency over commonly used zirconium fluoride (ZBLAN). Near-infrared pumping of a dysprosium-doped InF3 fiber results in broad emission centered around 4.3 {\mu}m, representing the longest emission yet achieved from a fluoride fiber. The first laser emission in an InF3 fiber is also demonstrated from the 3 {\mu}m dysprosium transition. Finally, a frequency domain excited state lifetime measurement comparison between fluoride hosts suggests that multiphonon effects are significantly reduced in indium fluoride fiber, paving the way to more efficient, longer wavelength lasers compared to ZBLAN fibers