A parallel demodulation system for extrinsic Fabry–Perot interferometer (EFPI) and fiber Bragg grating (FBG) sensors is presented, which is based on a Michelson interferometer and combines the methods of low-coherence interference and a Fourier-transform spectrum. The parallel demodulation theory is modeled with Fourier-transform spectrum technology, and a signal separation method with an EFPI and FBG is proposed. The design of an optical path difference scanning and sampling method without a reference light is described. Experiments show that the parallel demodulation system has good spectrum demodulation and low-coherence interference demodulation performance. It can realize simultaneous strain and temperature measurements while keeping the whole system configuration less complex.
© 2006 Optical Society of America
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.6200) Instrumentation, measurement, and metrology : Spectrometers and spectroscopic instrumentation
(300.6300) Spectroscopy : Spectroscopy, Fourier transforms
Instrumentation, Measurement, and Metrology
Junfeng Jiang, Tiegen Liu, Yimo Zhang, Lina Liu, Ying Zha, Fan Zhang, Yunxin Wang, and Pin Long, "Development of a parallel demodulation system used for extrinsic Fabry-Perot interferometer and fiber Bragg grating sensors," Appl. Opt. 45, 528-535 (2006)