A preform for a low loss fiber optic cable and method and apparatus for
fabricating such a preform is provided. The method includes providing
AlCl.sub.3 and CVD precursors and locally doping CaCl.sub.3. Alkali
and/or alkaline earth fluxing agents can be introduced. The alkali and/or
alkaline earths are doped along with the aluminum into the silica glass
core.