Characteristics of in-fiber Mach-Zehnder type interferometer in hollow-core photonic bandgap fiber

Mach-Zehnder interferometer based on off-set splicing technique of HC-PBGF and SMFs was fabricated. Interference fringe is observed with a maximum interferometric contrast of better than 12dB. We measured the strain, temperature, and refractive index response of the interferometer based on HC-PBGF.