Spectral transformation of megawatt femtosecond optical pulses in large-mode-area high-index-step photonic-crystal fibers

摘要

An assortment of photonic-crystal fibers with a core area varying from 20 to 50 μm{sup}2 is used to demonstrate efficient frequency conversion of megawatt femtosecond Cr:forsterite laser pulses with a central wavelength of 1.24 μm into the visible and infrared spectral ranges. Supercontinuum radiation with a spectrum spanning from 500 to 1800 nm and total output energy of hundreds of nanojoules is observed at the fiber output.