Chirp tuning of a fiber Bragg grating by using different tapered transducers and loading procedures: an application in the accelerometer

A uniform period fiber Bragg grating can be chirped by applying an axially strain gradient. We demonstrate a novel technique for making chirped fiber Bragg gratings (CFBG), which involves bonding an unchirped fiber grating to the surface of a tapered stainless steel plate that is strained by loading . Three kinds of tapered profiles (convex, gradient and concave) of plates and two kinds of loading procedures (bending and dilating) are used as the means for an in situ absolute center wavelength shifting and reflection ban dwidth broadening of a CFBG. Using this method, the center wavelength of a CFBG can be tuned from 1548.92 to 1550.99 nm, and a maximum adjustable chir p bandwidth of 2.00 nm is obtained for a fiber Bragg grating 50 mm in lengt h. An application in the accelerometer is introduced. (C) 2001 Society of P hoto-Optical Instrumentation Engineers.