A generation of an ultra-broad supercontinuum in tapered fibres

Summary form only given. We have observed ultra-broad supercontinuum generation in a conventional telecommunications optical fibre (cutoff wavelength ~1250 nm, NA = 0.1). The fibre was tapered (heated and stretched in a flame) to reduce its diameter to 1.8 μm uniformly over a 90 mm length, without significant loss. Pulses (200-500 fs) from a Ti:sapphire laser tuned to 850 nm were launched into the fibre. The output spectrum for a pulse energy of 3.2nJ, corresponding to 240 mW average power, is plotted. Our tapered fibres (mounted in simple dustproof housings) were robust, surviving several days without degradation. We therefore anticipate that tapered fibres will be effective hosts for a number of other nonlinear effects also.