Polarization independent silica based optical waveguide

摘要

An optical waveguide with low polarization dependency is provided. The silica based optical waveguide comprises a substrate (1), a core waveguide (2) formed thereon, and an over cladding part (3b) comprising a silica based glass with a refractive index lowering dopant and a refractive index increasing dopant added, formed on the substrate so as to cover the core waveguide. The segregation layer (3a) with a higher concentration of the refractive index increasing dopant is formed in contact with the substrate and the core waveguide. The over cladding part (3) is provided by forming a porous silica based glass layer by accumulating glass fine particles and a dopant such as B2O3 or P2O5 on the substrate (1) by FHD method so as to cover the core waveguide (2), then, sintering the porous silica based glass layer for transmitting the light in the core. <IMAGE>