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Practical spatial resolution limits of high-resolution fibre Bragg grating sensors using layer peeling



Robert J. Espejo, Shellee D. Dyer


Inverse scattering methods such as layer peeling have been shown to reconstruct the longitudinal refractive index of fiber Bragg gratings with very high resolution. These high spatial resolution measurements can be used to detect strain fields and thermal variations through the strain-optic and thermo-optic effects. However, physical constraints do not allow the refractive index to change on scales as short as these methods are capable of resolving. We demonstrate that this imposes a practical limitation of resolution on sensing applications. We use finite element modeling and compare this with experimental results. Longitudinal and transverse strains, as well as high resolution temperature sensing are considered. We show that the practical resolution limits are 40 micrometers for transverse stress sensing. 100 micrometers for longitudinal strain and 800 micrometers for thermal sensing.
Measurement Science & Technology


fiber Bragg gratings, fiber optic sensors, layer peeling, optical frequency-domain interferometry, temperature sensors, transverse strain sensors


Espejo, R. and Dyer, S. (2007), Practical spatial resolution limits of high-resolution fibre Bragg grating sensors using layer peeling, Measurement Science & Technology, [online], (Accessed June 15, 2024)


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Created April 12, 2007, Updated October 12, 2021