Fiber Segment Interferometry for Dynamic Strain Measurements

Kissinger, Thomas; Correia, Ricardo; Charrett, Thomas O. H.; James, Stephen W.; Tatam, Ralph P.

Abstract

Using a novel range-resolved interferometric signal processing technique based on the sinusoidal optical frequency modulation of a cost-effective laser diode, a fiber sensing approach termed fiber segment interferometry (FSI) is described. In FSI, a chain of long-gauge length fiber optic strain sensors are separated by identical in-fiber partial reflectors. Targeted at dynamic strain analysis and ultrasound detection for structural health monitoring, this approach allows integrated strain measurements along fiber segments, removing the sensing gaps and sensitivity to inhomogeneities found with localized fiber sensors. In this paper, the multiplexing of six fiber segments, each of length 12.5 cm, is demonstrated. The sensor array can be interrogated at 98 kHz data rate, achieving dynamic strain noise levels ≤ 0.14 nϵ · Hz -0.5 . The reflector fabrication is discussed, an analysis of linearity and noise performance is carried out and results from an exemplar experiment to determine the speed-of-sound of a stainless steel rod are shown.

Citation

Kissinger, T., Correia, R., Charrett, T. O. H., James, S. W., & Tatam, R. P. (2016). Fiber Segment Interferometry for Dynamic Strain Measurements. Journal of Lightwave Technology, 34(19), 4620-4626. https://doi.org/10.1109/jlt.2016.2530940

• Journal Article Type: Article
• Acceptance Date: Feb 12, 2016
• Online Publication Date: Feb 17, 2016
• Publication Date: Oct 1, 2016
• Deposit Date: Apr 27, 2020
• Publicly Available Date: Apr 28, 2020
• Journal: Journal of Lightwave Technology
• Print ISSN: 0733-8724
• Electronic ISSN: 1558-2213
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 34
• Issue: 19
• Pages: 4620-4626
• DOI: https://doi.org/10.1109/jlt.2016.2530940
• Keywords: Atomic and Molecular Physics, and Optics
• Public URL: https://nottingham-repository.worktribe.com/output/4350376
• Publisher URL: https://ieeexplore.ieee.org/document/7409931