Low-contrast photonic bandgap fibers and their potential applications in liquid-base sensors

A series of low-contract photonic band-gap (PBG) fibers were fabricated by filling the holes of a commercial air-silica hollow-core PBG fiber with different refractive index liquids. The PBGs and the transmission characteristics of these fibers were investigated theoretically and experimentally. An increase in the refractive index of liquid filling the holes causes blue-shift of the PBG and a narrow down of the PBG width, which may be exploited for sensitive refractive index measurement.