Bragg grating resonances in all-solid bandgap fibers

Bragg gratings are fabricated in all-solid photonic bandgap, fibers by forming a longitudinal periodic index modulation over the high-index rod lattice in the cladding. Due to its unique index-modulation pattern and the modal properties of the fiber, resonance couplings to the LP01 supermodes (also known as high-index rod modes) are observed. The corresponding peak is located at the long-wavelength side of the Bragg wavelength and presents the highest depth. The asymmetric index profile over the high-index rods, which is induced by side UV illumination, leads to broadening of the supermode resonance peaks and variation with fiber orientation in the bend response of the fiber grating. (C) 2007 Optical Society of America.