| 摘要 |
Glass preforms for optical fibers or the like having refractive index profiles which vary in stepped or graded fashion across the preform, are made from porous glass preforms by introducing a first dopant into the porous preform during manufacture, partially sintering the preform to selectively modify the internal surface area thereof, introducing a second vapor-infusible dopant into the selectively sintered preform to cause selective doping of the porous glass, and then consolidating the resulting doped preform to clear glass. |
