OPTICAL WAVEGUIDE GRATING AND METHOD OF MANUFACTURING THE SAME

摘要

In an optical fiber (l0), which has a clad region (l2) around a core region(11), of an optical waveguide grating, periodic refractive index variation occurs in a predetermined range (l3) extending in a direction of the optical axis of the core region (ll), the core region (ll) having composition of, for example, GeO2-P2O5-SiO2, the clad region (l2) comprising SiO2, a co-addition ratio in the core region (ll) being regulated, whereby the temperature dependency of the property thereof is reduced, an amount of addition of P2O5 in the core region (ll) being preferably not less than l/l5 times and not more than l times that of GeO2, and more preferably 0.6-l times that thereof.