Sensing characteristics of Long Period Gratings in air-core photonic bandgap fibers

In this paper we report on the fabrication and characterization of Long Period Gratings (LPGs) in hollow-core air-silica photonic bandgap fibers (HC-PCFs). The fabrication procedure is based on a pressure assisted Electrode Arc Discharge (EAD) technique. It relies on the combined use of EAD step, to locally heat the HC fiber, and of a static pressure (slightly higher than the external one) inside the fiber holes, to modify the holes. Here, the experimental fabrication of LPG prototypes with different periods and lengths are discussed. And, the sensitivity of LPGs in HC-PCF to environmental parameters such as strain, temperature and static pressure are presented and discussed.