Explain about the double-crucible method.

Low loss fibers are mostly manufactured by using double crucible and vapour phase deposition method.

The double-crucible method is the mainly common direct melt procedure. The double-crucible process combines the molten rods in a single perform by using two concentric crucibles. Optical fibers are drawn by this molten glass by using a same fiber drawing process as into vapor phase oxidation. A demonstration of a fiber drawing apparatus by using the double crucible process is illustrated in the given figure.

Double Crucible Fiber drawing process