In-line open-cavity Fabry-Pérot interferometer formed by C-shaped fiber fortemperaturein-sensitive refractive index sensing

Chuang Wu, Zhengyong Liu, Aping Zhang, Bai Ou Guan, Hwa Yaw Tam

Research output: Journal article publicationJournal articleAcademic researchpeer-review

70 Citations (Scopus)


We report an open-cavity optical fiber Fabry-Pérot interferometer (FPI) capable of measuring refractive index with very low temperature cross-sensitivity. The FPI was constructed by splicing a thin piece of C-shaped fiber between two standard single-mode fibers. The refractive index (RI) response of the FPI was characterized using water-ethanol mixtures with RI in the range of 1.33 to 1.36. The RI sensitivity was measured to be 1368 nm/RIU at the wavelength of 1600 nm with good linearity. Thanks to its all-glass structure, the FPI exhibits very low temperature crosssensitivity of 3.04 × 10-7RIU/°C. The effects of cavity length on the performance of the sensor were also studied. A shorter cavity gives rise to broader measurement range while offering larger detection limit, and vice versa. What's more, the effect of material dispersion of analyte on the sensitivity of open-cavity FPIs was identified for the first time. The sensor is compact in size and easy to fabricate. It is potentially useful for label-free optical sensing of chemical and biological samples.
Original languageEnglish
Pages (from-to)21757-21766
Number of pages10
JournalOptics Express
Issue number18
Publication statusPublished - 1 Jan 2014

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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