Blue-Extended Supercontinuum Generation in Photonic Crystal Fibers with Picosecond Pulse Pumping

We report supercontinuum generation extending to the blue spectral region using pulses of 1.8 ps duration at 1040nm in GeO2-doped core photonic crystal fibers. A spectrum in fundamental mode spanning from 415 nm to beyond 1750 nm is generated in a uniform photonic crystal fiber (PCF). A zero dispersion wavelength decreasing PCF is fabricated to optimize the parameters for deeper blue components generated by cross-phase modulation and group-velocity matching. Although the PCF is pumped at a low input power of 1.3 W in anomalous dispersion and relatively far from the zero dispersion wavelength, a flat continuum covering 406.1-671.8 nm is generated, which is of primary importance in a number of bio-photonic applications such as fluorescence imaging microscopy.