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Indexed by:Journal Papers

Date of Publication:2015-12-01

Journal:OPTICAL ENGINEERING

Included Journals:SCIE、EI、Scopus

Volume:54

Issue:12

ISSN No.:0091-3286

Key Words:optical fiber sensors; refractive index sensing; long-period grating; Michelson interferometer

Abstract:We report a high-resolution optical refractometer based on the long-period grating Michelson interferometer. The interferometer phase shift depends on the refractive index that surrounds the fiber probe. A cross-correlation signal-processing method is used to demodulate the interferometer phase shift. Experimental results show that a resolution of 3 x 10(-6) refractive index unit (RIU) can be obtained using this cross-correlation signal processing method. In addition, a measurement sensitivity up to 3 x 10(3) deg/RIU is showed as the surrounding refractive index changing from 1.33 to 1.42. Such high-resolution and low-cost optical refractometers would find more applications in chemical or biochemical sensing fields. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)