Fiber optic displacement sensor based on a double‐reflecting OTDR technique. Issue 6 (June 2015)

• Record Type: Journal Article
• Authors: Giraldi, Maria Thereza M. Rocco; Fernandes, Cindy S.; Ferreira, Marta S.; de Sousa, Marco J.; Jorge, Pedro; Costa, João C. W. A.; Santos, José L.; Frazão, Orlando
• Is Part Of: Microwave and optical technology letters. Volume 57:Issue 6(2015:Jun.)
• Page Start: 1312
• Page End: 1315
• Publication Date: 2015-06
• Subjects: optical fiber sensor -- fiber loop mirror -- interrogation system -- optical time domain reflectometer; Microwaves -- Periodicals; Optics -- Periodicals; 621
• DOI: 10.1002/mop.29086
• Languages: English
• ISSNs: 0895-2477

Abstract

ABSTRACT: In this work, it is proposed a technique to implement an intensity sensor based on the generation of a double‐reflecting (ghost) signal in optical time domain reflectometry (OTDR). The intensity sensor is supported by a singlemode‐multimode‐singlemode (SMS) fiber structure combined with a fiber loop mirror (FLM). The results of the displacement sensitivity show linear behavior for both the first‐reflecting and double‐reflecting signals with linear slopes of approximately −4.5 dB/mm and −6 dB/mm, respectively. The displacement resolution achieved is ∼0.28 mm. It is also found that the system is able to read periodic displacement variations in the millisecond time scale applied to the sensing head. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1312–1315, 2015