Abstract
A simple and highly sensitive phase-demodulation technique is proposed, and its use for a fiber Bragg grating strain sensor is experimentally demonstrated. Sampling a phase-modulated Mach–Zehnder output with controlled time delay produced two quadrature data streams that have relative quadrature phase difference (90°). The Bragg wavelength-dependent phase information is extracted by application of digital arctangent function and phase unwrapping to the quadrature signals. By use of this technique with a reference grating, strain sensing at as much as a 30-kHz sampling rate was obtained with strain resolution of 3.5 microstrains and 6 nanostrains/ in quasi-static and dynamic strain measurements, respectively.
© 2000 Optical Society of America
Full Article | PDF ArticleMore Like This
Markus Schmidt, Norbert Fürstenau, Wojtek Bock, and Waclaw Urbanczyk
Opt. Lett. 25(18) 1334-1336 (2000)
Heming Wei, Chuanyi Tao, Yinian Zhu, and Sridhar Krishnaswamy
Appl. Opt. 55(10) 2752-2759 (2016)
Serge M. Melle, Kexing Liu, and Raymond M. Measures
Appl. Opt. 32(19) 3601-3609 (1993)