Femtosecond IR laser fabrication of Bragg gratings in photonic crystal fibers and tapers

Fiber Bragg gratings were written in pure silica photonic crystal fibers (PCFs) and PCF tapers with 125-fs 800-nm infrared radiation. High reflectivities were achieved with short exposure times in the tapers. Both multimode and single-mode grating reflections were achieved in the fiber tapers.