High-Power Broadly Tunable 3-<named-content content-type="math" xlink:type="simple"> <inline-formula> <tex-math notation="TeX">$\mu\hbox{m}$</tex-math></inline-formula></named-content> Fiber Laser for the Measurement of Optical Fiber Loss

Abstract

We demonstrate a Ho 3þ , Pr 3þ co-doped fluoride fiber laser that produces an output power of 7.2 W, a 150-nm tuning range, and a narrow linewidth of G 0:14 nm using a power-scalable Yb 3þ fiber-laser-pumped 1150-nm Raman fiber laser as the excitation source. The maximum output power is achieved at a slope efficiency of 29%, with wavelength tuning between 2825 and 2975 nm that overlaps with the OH absorption region in many mid-infrared transparent glasses. The system is used to provide accurate measurements of the background scattering loss and the degree of water incorporation in the rare-earth-doped core of commercial double-clad fluoride fiber; the high power allows accurate core loss measurements for quite lossy fibers. Furthermore, the spectral location of the OH absorption feature was observed to be dependent on glass composition shifting from 2872 nm in undoped ZBLAN to 2896 nm upon Ho 3þ Pr 3þ co-doping, whereas As 2 S 3 glass was observed to have an OH peak location of 2911 nm.

Raman fiber lasers

“…An 1150 nm Raman fiber laser with 110 W of output power was used to pump a Hodoped fiber laser to generate 42 W of output power near 2048 nm [146]. 1150 nm Raman fiber lasers have also been used to pump Ho-doped ZBLAN fibers to generate 3 μm fiber lasers [147,148].…”

Advances in Mid-IR Fiber Lasers: Tellurite, Fluoride and Chalcogenide

“…In [29], a Ho 3+ /Pr 3+ co-doped fluoride fiber laser with an output power of Ps = 7.2 W was demonstrated. It exhibited a slope efficiency of η = 29% and a wavelength tuning range Δλ between In addition to erbium, other dopants have been successfully employed.…”

Ho3+ doped fluoroaluminate glass fibers for 2.9 µm lasing

“…In 2009, Jackson reported a 2.86 µm Ho 3+ , Pr 3+ -codoped ZBLAN fiber laser by using a 1100 nm Yb 3+ -doped silica fiber laser as the pump source and the maximum output power was ~2.5 W [14]. In 2015, Crawford et al demonstrated a 7.2 W tunable Ho 3+ , Pr 3+codoped ZBLAN fiber laser with a 150-nm tuning range from 2825 to 2975 nm [15]. However, ZBLAN glasses have poor water resistance and thermal stability [16], and therefore it is still necessary to develop other glass hosts with high stability for constructing 2.9 µm fiber lasers.…”