title: An Optical Fiber Displacement Sensor Using RF Interrogation Technique.
abstract: We propose a novel non-contact optical fiber displacement sensor. It uses a radio frequency (RF) interrogation technique which is based on bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). The displacement is measured from the free spectral range (FSR) which is determined by the dip frequencies of the modulated MZ-EOM transfer function. In experiments, the proposed sensor showed a sensitivity of 456 kHz/mm or 1.043 kHz/V in a measurement range of 7 mm. The displacement resolution of the proposed sensor depends on the linewidth and the power of the optical source. Resolution better than 0.05 μm would be achieved if an optical source which has a linewidth narrower than 1.5 nm and a received power larger than -36 dBm is used. Also, the multiplexing characteristic of the proposed sensor was experimentally validated.
authors.affiliation: Department of Electrical Engineering and Smart Grid Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 54896, Korea. khhjjh@jbnu.ac.kr.
authors.forename: Hyeon-Ho
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Department of Electrical Engineering and Smart Grid Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 54896, Korea. sang_jin@jbnu.ac.kr.
authors.forename: Sang-Jin
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Wind Valley Co. Ltd., 4 Yulchonsan-daero, Haeryong-myeon, Suncheon 58025, Korea. ksjeon@windvalley.kr.
authors.forename: Keum Soo
authors.initials: KS
authors.lastname: Jeon
authors.affiliation: Department of Electrical Engineering and Smart Grid Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 54896, Korea. pan@jbnu.ac.kr.
authors.forename: Jae-Kyung
authors.initials: JK
authors.lastname: Pan
keywords: Mach-Zehnder electro-optical modulator (MZ-EOM); free spectral range (FSR); optical fiber displacement sensor; radio frequency (RF); wavelength division multiplexing (WDM)