Fibre optic coupler.

摘要

A fibre-optic coupler has the claddings of two or more optical fibres partially fused together over a coupling region, and a body of light-transmissive material, having a variable refractive index, contacts the claddings at the coupling region, such that by varying the refractive index of said body light transmitted along one fibre is split between the fibres in a varying ratio.