Release Time:2020-02-17  Hits:

Indexed by: Conference Paper

Date of Publication: 2019-01-01

Included Journals: CPCI-S、EI

Volume: 11209

Key Words: Fiber optics; Fabry-Perot; sensors; femtosecond laser; refractive index; open cavity; all-silica; micromachining

Abstract: We propose and demonstrate an open-cavity fiber extrinsic Fabry-Perot (FP) interferometer (EFPI), fabricated by using 800 nm femtosecond (fs) laser micromachining, for refractive index (RI) measurement. The sensor probe consists of two single-mode fiber (SMF) and a notched hollow-core fiber (HCF) fused together to form an all-silica structure of SMF-HCF-SMF. The open micro-cavity is formed by removing part of the HCF in the center of its surface by fs laser micromachining technology, allowing liquid or gaseous sample to flow in. Such a sensor can provide an extremely high-precision RI measurement of 10(-6) RIU (refractive index unit) and the sensitivity can reach up to 4x10(5) nm/RIU within the range between 1.355 and 1.374.