Temperature or strain induced adjustable-chirp characteristics of uniform fibre grating with tapered metal coating

Temperature and strain characteristics of uniform fibre grating with tapered metal coatings have been analysed theoretically, by which adjustable chirp characteristics of such gratings are shown. Electroplating is adopted to fabricate such gratings, and the tapered metal coating is obtained by gradually drawing the fibre grating out of the solution during the process of electroplating. The gradually changing cross-sectional area of the metal coating is calculated by a newly suggested numerical method. By combining the theoretical and numerical simulation analyses, the gratings' characteristics are given at various temperatures and strains. The results obtained using such a method are also testified by experiments.