A molded polymeric resin-filled coupler

A type of molded polymeric resin-filled coupler has been built with the goal of making a low-cost and manufacturable 1×N multimode optical coupler. The coupler consists of a low-index thermoplastic molded cladding piece part containing an optically finished waveguide channel. The channel is covered with a flat lid of the same material and is filled with a high index resin to form a mode mixing waveguide. Optical fibers are inserted into both ends of the channel before it is filled to complete the pigtailed device. This design accomplished all required tasks with just two materials: the molded low index structural part which provides the waveguide cladding, and the high index waveguide core part which provides the adhesive to hold the fibers in place and the optical refractive index matching to reduce reflections. Two material systems have been used to construct 1×23 couplers. Typical coupler excess losses are less than 2 dB, and the uniformity among all fibers is better than 1-dB standard deviation