Mid-infrared extension of supercontinuum in chalcogenide suspended core fibre through soliton gas pumping

Reported is an experimental demonstration of the mid-infrared extension of supercontinuum in a 1.9 μm suspended core chalcogenide fibre, the zero dispersion wavelength of which is shifted to 1.9 μm, i.e. into the transparency window of standard silica fibres. Based on the well-known long-pulse regime of supercontinuum generation in silica fibre, a low-cost optical quasi-CW source at 1.53 μm has been converted and shifted into a large number of interacting femtosecond solitons localised up to 2.1 μm. This optical source, called a soliton gas, allows the pumping of a 50 cm long chalcogenide microstructured fibre near its zero dispersion wavelength, thus leading to an efficient extension of a mid-infrared supercontinuum beyond 2.4 μm.