Calculation of the frequency response in step-index plastic optical fibers using the time-dependent power flow equation

The time-dependent power flow equation, which is reduced to its time-independent counterpart is employed to calculate frequency response and bandwidth in addition to mode coupling and mode-dependent attenuation in a step-index plastic optical fiber. The frequency response is specified as a function of distance from the input fiber end. This is compared to reported measurements. Mode-dependent attenuation and mode dispersion and coupling are known to be strong in plastic optical fibers, leading to major implications for their frequency response in data transmission systems.

Research highlights
► At short fiber lengths the mode-dependent attenuation is dominant.
► With increasing fiber length, mode coupling begins to influence the impulse response of the fiber.
► The switch from weakly to strongly coupled regimes results in the slower drop of bandwidth for fibers longer than the coupling length Lc, which means that mode coupling enhances the fiber bandwidth.