Multi-watt mid-infrared supercontinuum generated from a dehydrated large-core tellurite glass fiber

Abstract

We report for the first time multi-watt mid-infrared supercontinuum (SC) output from a dehydrated tellurite step-index fiber. The tellurite glass preform is melted in a dry-atmosphere filled glovebox and the water impurity in the glass has been reduced to 1ppm level. The fiber has a large core diameter of 12 µm and a numerical aperture (NA) of 0.21. Using the amplified Raman-shifted soliton pulses from a 1.55 µm erbium-doped fiber laser as the pump, a broadband 2-3 µm supercontinuum with a 3dB bandwidth of 985 nm has been generated from an 80cm-long dehydrated tellurite glass fiber. The power spectral density of the SC is above 3.5 dBm/nm in the whole range of 2-3 µm. The net output power of the supercontinuum from the tellurite fiber is measured to be 2.1 W. To the best of our knowledge, this is the highest average power of mid-IR SC generated from a tellurite fiber. The spectral density of above 3 dBm/nm is also one of the highest spectral densities of a SC achieved in 2.5-3 μm range from an oxide glass fiber.