<title>Novel chirp tuning technique for fiber Bragg gratings without center wavelength shift using simply supported beam</title>

Abstract

We present a novel technique to produce adjustable chirped fiber gratings that allows the spectral width tuning without center wavelength shift. The chirp rate can be precisely controlled by bending the uniform fiber Bragg grating (FBG) surface-mounted on one side of a simply supported beam. This technique allows the dynamic control of the spectral width of the chirped grating. It has a simple structure with a linear strain gradient. Both compression and tension are simultaneously applied to the beam, so center wavelength shift is avoided. In the experiment, a maximum spectral width of 18.3 nm is obtained, which corresponds to a chirp rate of 3.05 nm/cm. To the best of our knowledge, this is the largest chirp rate produced on a uniform FBG by using strain-gradient beam tuning technique. The proposed technique can also be used to tune the chirp rate of a linearly chirped grating.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.