Distributed strain measurement based on a fiber Bragg grating and its reflection spectrum analysis

Abstract

A method of extracting the strain profile along a fiber Bragg grating from the intensity reflection spectrum is described. The procedure is based on a filter synthesis theory that relates the aperiodicity of a grating with its reflection spectrum. To illustrate the approach, we measured the strain profile near a hole in a plate and obtained a strain resolution of 80 μ∈. The spatial resolution depends on the strain gradient

i.e., the higher the gradient, the better the resolution. A resolution of 0.8 mm was achieved for a 5-mm grating with a gradient of 250 μ∈/mm. © 1996 Optical Society of America.