Efficient white light generation in secondary cores of holey fibers

We report the generation of white light from a picosecond pump by efficient four-wave mixing processes. A 530 nm green source based on a frequency-doubled Yb-doped fiber laser generates strong red and blue sidebands in the secondary cores of a holey fiber with large air-filling factor. Phase matching is attributed to birefringence within the submicrometer-sized secondary cores induced by non-symmetric deformation during the fiber drawing. (c) 2007 Optical Society of America.