Calculation of the coupling coefficient in strained step index plastic optical fibers

The coupling coefficient in a strained step index plastic optical fiber is determined using our recent simplified method. This enabled the calculation of the length z(s) at which the steady-state distribution (SSD) is achieved. Results are in good agreement with measurements reported earlier. The strained fiber shows a much stronger mode coupling than the unstrained one of the same type. Consequently, the fiber length for achieving the SSD is much shorter for strained than unstrained fibers.