Plastic optical fiber star coupler

A new plastic optical fiber star coupler and the means of fabricating it have been developed. This coupler has been realized by twisting and pulling the waist region of a biconical tapered fiber bundle made by pretapered fibers while heating. Controlling the biconical tapered shape has been achieved by jetting gas on the fiber surface while heating the fiber bundle. By using this fabrication method, the desired diameter mixing portion can be formed without breakage from melting. Low-cost optical star couplers with large port number, low excess loss, and small power deviation can be obtained.