Steady-state characteristics of multimode W-type fibers.

The steady-state characteristics of multimode W-type fibers are investigated by solving the coupled-power equation numerically. It is shown that the steady-state power distributions depend on both the intermediate layer width and the coupling strength. Unlike singly clad fibers, the steady-state loss (coupling-induced loss) in W-type fibers is not proportional to the coupling strength. The loss in W-type fibers varies between the value for two types of singly clad reference fibers as the coupling strength changes.