Management of OH absorption in tellurite optical fibers and related supercontinuum generation

• Fabrication of low-OH content and low-loss tellurite optical fibers.
• Incorporation of fluoride ions makes tellurite fibers transparent up to 4 μm.
• 2000 nm bandwidth supercontinuum in suspended core microstructured tellurite fiber.

We report the fabrication and the characterization of low OH content and low loss tellurite optical fibers. The influence of different methods of glass fabrication on fiber losses has been investigated. The use of the purest commercial raw materials can reduce the losses below 0.1 dB/m at 1.55 μm. Incorporation of fluoride ions into the tellurite glass matrix makes the optical fibers transparent up to 4 μm. A suspended core microstructured fiber has been fabricated and pumped by nanojoule-level femtosecond pulses, thus resulting in more than 2000-nm bandwidth supercontinuum after a few centimeters of propagation.