The coherence properties of supercontinuum spectra generated in photonic crystal fiber

Temporal coherence property of supercontinuum (SC) generated in a polarization-maintaining photonic crystal fiber (PM-PCF) pumped by Ti:sapphire fs laser was experimentally studied by using a modified Michelson interferometer. The coherence length of supercontinuum light was measured to characterize the temporal coherence property. The coherence lengths of supercontinuum and pump laser were measured to be 6.5 μm and 59.14 μm, respectively. The shortened coherence length of supercontinuum output from the PM-PCF was due to the broadened spectrum. Moreover, the interferogram evolution versus the supercontinuum spectra was also investigated. It was indicated that the flatter the supercontinuum was, the better the interferogram was.