A simple and compact refractive index sensor is demonstrated by tapering a photonic crystal fiber (PCF) in-line interferometer. The PCF is spliced between two single-mode fibers and tapered via hydrofluoric acid etching. Its sensitivity in liquid is more than an order of magnitude larger than the untapered one. By optimizing the etching process, we can fabricate more uniformly and thinly tapered PCF interferometers with higher sensitivity in the future.
© 2012 Chinese Optics Letters
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(280.4788) Remote sensing and sensors : Optical sensing and sensors
(060.5295) Fiber optics and optical communications : Photonic crystal fibers
Fiber Optics and Optical Communications
Qi Liu and Qin Wang, "Refractive index sensor based on tapered PCF in-line interferometer," Chin. Opt. Lett. 10, 090601-090601 (2012)