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
Original Manuscript: March 27, 1996
Published: September 1, 1996
M. LeBlanc, A. Guemes, A. Othonos, S. Y. Huang, M. Ohn, and R. M. Measures, "Distributed strain measurement based on a fiber Bragg grating and its reflection spectrum analysis," Opt. Lett. 21, 1405-1407 (1996)