Abstract

Several methods have been demonstrated for fabricating tunable fiber Bragg Gratings (FBG) such as mask image projection using imaging lens [1] and tilting the fiber at an angle respect to the phase-mask allowing a change in the grating period [2]. Center wavelength of FBG can also be tuned by applying strain to the fiber prior the fabrication so that, upon relaxation, a smaller Bragg wavelength is obtained [3]. Following this approach, center wavelength of FBG can be selected in a wide spectral range. During the fabrication process the index of refraction of the fiber core changes with the exposure time of the fiber to UV light, leading to a variation in the Bragg wavelength and reflectivity of the FBG. However, the dynamic of the writing process changes considerably as a variable strain is applied to the fiber. In this paper, we present a method for writing multiple FBG at different center wavelengths using a single phase-mask. Fabrication parameters such as applied strain and exposure time are chosen in order to obtain FBG with the center wavelength and reflectivity desired.

© 2003 Optical Society of America