Spectral Broadening in a Polarization-Maintaining Photonic Crystal Fibre by Femtosecond Pulses from an Optical Parametric Amplifier

The spectral broadening with the bandwidth of 83nm (1.2486--1.3318μm) in the 1.3μm region is achieved in a 0.2-m-long, polarization-maintaining photonic crystal fibre (PCF) with an average core radius of 1.8μm, pumped by optical pulses at the wavelength 1.269μm, with the duration 250fs and the repetition rate 250kHz from an optical parametric amplifier. The polarization characteristics of the output spectra are also investigated.