A type of extrinsic Fabry-Perot interferometer (EFPI) fiber optic sensor, i.e., the microcavity strain sensor, is demonstrated for embedded, high-temperature applications. The sensor is fabricated using a femtosecond (fs) laser. The fs-laser-based fabrication makes the sensor thermally stable to sustain operating temperatures as high as 800 °C. The sensor has low sensitivity toward the temperature as compared to its response toward the applied strain. The performance of the EFPI sensor is tested in an embedded application. The host material is carbon fiber/bismaleimide (BMI) composite laminate that offer thermally stable characteristics at high ambient temperatures. The sensor exhibits highly linear response toward the temperature and strain. Analytical work done with embedded optical-fiber sensors using the out-of-autoclave BMI laminate was limited until now. The work presented in this paper offers an insight into the strain and temperature interactions of the embedded sensors with the BMI composites.


Electrical and Computer Engineering

Second Department

Mechanical and Aerospace Engineering

Research Center/Lab(s)

Intelligent Systems Center


The authors acknowledge the support of National Science Foundation project under Grant CMMI-1200787. This research was sponsored in part by Integrated Systems Solutions, Inc. The authors would like to thank Stratton Composite Solutions for the materials supplied.

Keywords and Phrases

Carbon; Carbon fibers; Composite structures; Fiber optic sensors; Fibers; High temperature applications; Interferometers; Laminated composites; Microcavities; Optical fiber fabrication; Optical fibers; Temperature; Thermodynamic stability; Bismaleimides; Embedded sensors; Extrinsic Fabry Perot interferometer; Strain analysis; Structural monitoring; Fabry-Perot interferometers; Extrinsic Fabry-Perot interferometer; Optical-fiber sensor

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

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Publication Date

01 Mar 2016