Abstract

Compact, robust and efficient laser sources near 3 µm are needed for applications such as laser surgery, mid-infrared laser pumping and sensing. Extending the benefits of fiber laser technology to this wavelength region has proven a significant challenge, mainly due to the limited number of host glasses with maximum phonon energies that are sufficiently low for emission at this wavelength. Recent results [1] have shown that erbium-doped fluoride glass appears to be an ideal candidate, thanks to the recent availability of high quality, low loss double-clad fibers, the capability of low loss fusion splicing and a strong photosensitivity that allows writing strongly reflective fiber Bragg gratings (FBGs) [2]. QCW fiber lasers are ideal for materials processing applications due to the capability of adjusting pulse duration, peak power and repetition rate and thus control the process. This versatility is especially important in applications such as laser surgery, where one wants to control both ablation depth and limit collateral thermal damage. There have been a limited number of demonstrations of QCW emission in 3 µm Er³⁺-doped fluoride glass and all have shown significant output power as well as wavelength fluctuations that would limit the useful applications of these lasers [3].

© 2011 Optical Society of America