Supercontinuum generation in heavy-metal oxide glass based suspended-core photonic crystal fibers

In this paper we investigate supercontinuum generation in several suspended-core soft-glass photonic crystal fibers pumped by an optical parametric oscillator tunable around 1550 nm. The fibers were drawn from lead-bismuth-gallium-cadmium-oxide glass (PBG-81) featuring a wide transmission window from 0.5 to 2.7 μm and a high nonlinear refractive index up to 4.3·1019  m2/W. They have been specifically designed with a microscale suspended hexagonal core for efficient supercontinuum generation around 1550 nm. We experimentally demonstrate two supercontinuum spectra spanning from 1.07 to 2.31 μm and 0.89 to 2.46 μm by pumping two PCFs in both normal and anomalous dispersion regimes, respectively. We also numerically model the group velocity dispersion curves for these fibers from their scanning electron microscope images. The results are in good agreement with numerical simulations based on the generalized nonlinear Schrödinger equation including the pump frequency chirp.