title: Photonic crystal fiber half-taper probe based refractometer.
abstract: A compact single-mode photonic crystal fiber single-mode fiber tip (SPST) refractive index sensor is demonstrated in this Letter. A CO2 laser cleaving technique is utilized to provide a clean-cut fiber tip, which is then coated by a layer of gold to increase reflection. An average sensitivity of 39.1 nm/RIU and a resolvable index change of 2.56×10(-4) are obtained experimentally with a ∼3.2 μm diameter SPST. The temperature dependence of this fiber-optic sensor probe is presented. The proposed SPST refractometer is also significantly less sensitive to temperature and an experimental demonstration of this reduced sensitivity is presented in the Letter. Because of its compactness, ease of fabrication, linear response, low temperature dependency, easy connectivity to other fiberized optical components and low cost, this refractometer could find various applications in chemical and biological sensing.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Wang
authors.forename: Ming
authors.initials: M
authors.lastname: Ding
authors.forename: Lin
authors.initials: L
authors.lastname: Bo
authors.forename: Chunying
authors.initials: C
authors.lastname: Guan
authors.forename: Yuliya
authors.initials: Y
authors.lastname: Semenova
authors.forename: Weimin
authors.initials: W
authors.lastname: Sun
authors.forename: Libo
authors.initials: L
authors.lastname: Yuan
authors.forename: Gilberto
authors.initials: G
authors.lastname: Brambilla
authors.forename: Gerald
authors.initials: G
authors.lastname: Farrell