Optical Fibers with Polygonal Cladding

Fabrication of optical fibers with a polygonal cladding was studied. The glass preform for that fiber was made by consolidation of a soot preform with a polygonal cladding that results from cutting a round hybridized soot preform produced by the direct cold isostatic pressing (CIP) process. That optical fiber was drawn at a temperature as low as 1850°C from a glass preform with a polygonal cladding. Fibers with a square cladding, a regular octagonal cladding, and a rectangular cladding were realized by the method mentioned above. The transmission loss of a square fiber measured 0.69 dB/km at 1.3 μm. A fiber with a rectangular cladding and an eccentric core was also made advantageously by this method.