Variable-ratio tap for plastic optical fiber

A variable-ratio tap is developed by changing the bending radius of a plastic optical fiber. When a plastic fiber is bent over a small radius, the core modes of the fiber are converted into the cladding modes, which can be extracted through material having a suitable refractive index. The transmission characteristics of the variable-ratio tap are investigated using the ray tracing technique governing the quasiskew rays propagating through a multimode fiber.