Side-coupling of polymer optical fibers and its applications

Reflection based side couplings into or out of glass fibers were reported using either fusion splicing of graded index fiber or using mechanical cutting methods. However, the availability of polymer optical fibers (POFs) makes it possible to further simplify mirror preparation operations so that massive production of such low cost side couplers is feasible. Both the conventional reflection and the total internal reflection can easily be implemented through mirrors formed inside a POF using mechanical or other types of etching techniques. We show two conventional micro-mirrors which an embedded into a POF through a serious of microcutting, masking, metallic coating, and polymer refilling. A mirror can be formed either by satisfying the total internal reflection condition of the etched interface or by metal deposition using a conventional metallic mirror coating process.