Fabrication of high concentration rare-earth-doped silica-based waveguide by MCVD method

Reports a technique of fabricating a buried channel silica-based optical waveguide containing the largest rare-earth concentration ever reported, i.e., 3 wt% in Nd/sub 2/O/sub 3/. Instead of the flame hydrolysis technique, these waveguides are manufactured by the standard MCVD method originally designed for fiber preform fabrication.>