We propose and experimentally demonstrate a simple and practical scheme for simultaneous measurement of bending and temperature based on a single sampled chirped fiber Bragg grating with multiple resonant peaks, which is embedded on a flexible cantilever beam. The wavelength spacing of the grating can be changed by adjusting the bending curvature change, since the compressive strain gradient induced by the bending of the cantilever beam changes the chirp ratio of the fiber grating. However, the wavelength spacing of the fiber grating is not changed by the temperature variation; the multiple resonant wavelengths are only shifted into the longer wavelength because of the positive thermal-expansion and thermo-optic coefficients of the fiber grating. Consequently, the proposed scheme allows for discrimination between two effects of bending and temperature.
© 2006 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: May 9, 2006
Revised Manuscript: June 28, 2006
Manuscript Accepted: June 30, 2006
Published: September 11, 2006
Young-Geun Han, Xinyong Dong, J. H. Lee, and S. B. Lee, "Simultaneous measurement of bending and temperature based on a single sampled chirped fiber Bragg grating embedded on a flexible cantilever beam," Opt. Lett. 31, 2839-2841 (2006)