Abstract

We experimentally demonstrated a high-sensitivity gas pressure sensor based on long period fiber grating (LPFG) inscribed in an air-core photonic bandgap fiber (PBF). It was constituted by a thin piece of silica tube sandwiched between a single mode fiber (SMF) and an LPFG inscribed in air-core PBF. Then a micro-hole was drilled through the surface of the silica tube by use of a femtosecond laser to allow external gas to access into the air-holes of the PBF. Such a LPFG-based sensor device exhibits a high gas pressure sensitivity of up to -1.30 nm/MPa, which is near one order magnitude higher than that of LPFG without external gas filling in the air-holes of the PBF.

© 2016 Optical Society of America