Bragg Gratings in All-Solid Bragg Photonic Crystal Fiber Written With Femtosecond Pulses

Bragg gratings were fabricated in all-solid Bragg photonic crystal fibers with 100 fs, 800 nm infrared radiations and a phase mask. Both multimode and single-mode grating resonances were achieved by accurately adjusting the focal position of the irradiation beam in the Bragg fiber. Thermal annealing investigations indicated that the gratings were induced by Type I-IR and Type II-IR refractive index change. Typical Bragg wavelength shifted with the change of temperature and strain, which were measured respectively.