Efficient supercontinuum generations in silica suspended core fibers

Abstract

We have experimentally studied supercontinuum generations in highly nonlinear suspended core silica fibers as alternatives to photonic crystal fibers. Octave-spanning spectrum can be easily generated at peak pump power levels as low as approximately 1.5 kW at 1 microm and approximately 1 kW at 800 nm, which effectively enables f ceo stabilization of mode-locked fiber lasers without further amplification. Experiments also confirm that the blue edge of the supercontinuum undergoes a two-phase growth process, an initial fast growth governed by phase-matched dispersive wave generation and a second slower growth governed by group-velocity-matched cross-phase modulation. We have further experimentally shown that the fundamental solitons generated from the initial fission process can be independent of pump powers and the orders which they are generated. Furthermore, while the fundamental soliton wavelength undergoes continuous red shift by Raman scattering, they continuously lose power to longer wavelength dispersive waves where phase-matching to this long wavelength dispersive wave is allowed and, otherwise, maintain its initial power where phase-matching to long wavelength dispersive wave is not allowed. We also demonstrated that total suppression of dispersive wave generation at short wavelength can be achieved in the absence of dispersion slope at the pump wavelength.