| 摘要 |
Improved single-mode optical waveguide fibers comprising a central core (10) region, surrounded by an inner cladding region (22) through which light at a chosen signal wavelength will propagate to an appreciable degree along with propagation of same in the central core region (10), the inner core region further surrounded by an outer cladding region (17), the improvement comprising germanium dioxide in the inner cladding region (22) at a concentration within the range of about .005 percent by weight to about 1 percent by weight of said inner cladding region (22), effective to significantly reduce the concentration of oxygen atoms in the inner cladding region (22) which are available to form defects that cause hydrogen-induced attenuation. Also provided are core preforms, overclad preforms, and processes for making the fibers, core preforms and overclad preforms. <IMAGE> |
