Pushing the blue side of supercontinuum using photonic crystal fiber

By utilizing the versatile dispersion properties and enhanced nonlinearity of all-silica solid-core photonic crystal fiber, supercontinnum sources extending from below 400 nm up to the near-infrared have been generated (P. St.J. Russell, J. Lightwave Tech. 24, 2006, pp. 4729–4749). The spectral range is usually limited by the transmission properties of the material and alternative ways to extend the achievable wavelengths must be found. One possibility is to use exotic glass such as heavy-metal oxide, chalcogenide or fluoride-based glass. Unfortunately, the viscosity of these glasses rapidly changes with temperature and the suitable range of drawing temperature is considerably reduced compare to silica. Microstructured fibers made of such glasses are therefore extremely challenging to produce. On the other hand, they are ideal candidates for ultra-broad supercontinuum because of their very large transmission window (from ∼200nm to above 7 µm for ZBLAN). We recently successfully drew ZBLAN PCF. We will present here recent results on the generation of ultrabroad supercontinuum is such fibers.