Simple method for making tunable chirping on a uniform fiber Bragg grating

Chirped Bragg gratings are commonly utilized in optical fiber communication systems for chromatic dispersion compensation, because they realize a large dispersion and have very small dimensions and low insertion loss. Chirping can be obtained during the writing of the grating, for example, by bending the fiber so that a continuously changing period is projected on it or by applying a non-uniform strain on the fiber during irradiation, or by using a chirped phase mask. It is also possible to obtain and tune a chirped grating after the fabrication of grating by applying a temperature gradient or a strain gradient along the fiber. In this work we propose a simple technique for making tunable chirped gratings, which consists of the application of a uniform Bragg grating to the lateral side of a beam which was subsequently bent.