Multiport optical communication system and optical star structure therefor

Abstract

A multiport optical cable or bus, composed of bundles of parallel fibers interconnected by an optical star structure, has a higher packing fraction and greater efficiency in the mixing and redistribution functions because the star's radiating arms have their individual cladding layers omitted or removed and because they are fused together to form the mixer section or a part of it. Where the numbers of input and output ports and arms are unequal, the unclad arms have their fused portions optically spliced or connected to form a composite mixer section. Several sections may be cascaded, using the same structural principles, to provide additional lower-level optical outputs for control or other purposes. The cladding function for the star structure is provided by separately encasing the radiating arms and mixer section or sections in a light-reflecting material. Preferably, this is a plastic potting compound having an optical index of refraction lower than those of the star arms or mixer portions. Alternatively, a metallic reflective coating may be applied. The invention has particular utility as applied to optical buses comprised of fibers of the plastic clad silica type.

Dependencies are inferred from the claim text.