25.8 W All-Fiber Mid-Infrared Supercontinuum Light Sources Based on Fluorotellurite Fibers

In this letter, we demonstrate a 25.8 W all-fiber mid-infrared supercontinuum (SC) light source based on fluorotellurite fibers. All-solid fluorotellurite fibers are fabricated by using a rod-in-tube method. A 56 cm long fluorotellurite fiber with a core diameter of
$\sim 11~\mu \text{m}$
is used as the nonlinear medium and a high power
$1.93\sim 2.5~\mu \text{m}$
SC fiber laser as the pump source. The fluorotellurite fiber is connected to the output silica fiber of the pump source by direct fusion splicing, leading to the formation of the compact all-fiber structure. For a pump power of ~42.6 W, we obtain a 25.8 W SC light source with a spectral range from 0.93 to 3.99
$\mu \text{m}$
. The corresponding optical-to-optical conversion efficiency is about 60.6%. To the best of our knowledge, this is the first time to report all-fiber high power mid-infrared SC light source based on fluorotellurite fibers. Our results pave the way to apply mid-infrared SC light sources based on fluorotellurite fibers for real applications.