A selectively liquid-filled photonic-bandgap-fiber-based Sagnac interferometer is proposed and demonstrated. Extraordinary transmission and sensing characteristics of the interferometer are observed and investigated theoretically and experimentally. Due to the unique modal and group birefringence characteristics of the material-infiltrated photonic bandgap fiber, the temperature sensitivity of the interference peaks strongly depends on the wavelength. Furthermore, the interference peaks at the two edges of the bandgap appear to shift in the opposite direction alongside changes in the temperature, providing a method of achieving two- or multi-parameter simultaneous sensing measurement with a compact structure.
© 2012 American Institute of Physics.
American Institute of Physics