title: Miniature tapered photonic crystal fiber interferometer with enhanced sensitivity by acid microdroplets etching.
abstract: We fabricate a miniature tapered photonic crystal fiber (PCF) interferometer with enhanced sensitivity by acid microdroplets etching. This method is very simple and cost effective, avoiding elongating the PCF, moving and refixing the device during etching, and measuring. The refractive index sensing properties with different PCF diameters are investigated both theoretically and experimentally. The tapering velocity can be controlled by the microdroplet size and position. The sensitivity greatly increases (five times, 750 nm/RIU) and the size decreases after slightly tapering the PCF. The device keeps low temperature dependence before and after tapering. More uniformly and thinly tapered PCFs can be realized with higher sensitivity (∼100 times) by optimizing the etching process.
authors.affiliation: College of Engineering and Applied Sciences and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, China.
authors.forename: Sun-jie
authors.initials: SJ
authors.lastname: Qiu
authors.forename: Ye
authors.initials: Y
authors.lastname: Chen
authors.forename: Jun-long
authors.initials: JL
authors.lastname: Kou
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.forename: Yan-qing
authors.initials: YQ
authors.lastname: Lu