  This paper presents a three layer index guided lead silicate (SF57) photonic
crystal fiber which simultaneously promises to yield large effective optical
nonlinear coefficient and low anomalous dispersion that makes it suitable for
supercontinuum generation. At an operating wavelength 1550 nm, the typical
optimized value of anomalous dispersion and effective nonlinear coefficient
turns out to be ~4 ps/km/nm and ~1078 W^(-1) km^(-1), respectively. Through
numerical simulation it is realized that the designed fiber promises to exhibit
three octave spanning supercontinuum from 900 to 7200 nm by using 50 fs sech
optical pulses of 5 kW peak power. Due to the cross-phase modulation and
four-wave mixing processes, a long range of red-shifted dispersive wave
generated, which assist to achieve such large broadening. In addition, we have
investigated the compatibility of supercontinuum generation with input pulse
peak power increment and briefly discussed the impact of nonlinear processes on
supercontinuum generation.
