Transmission characteristics of multimode W-type optical fiber: experimental study of the effect of the intermediate layer.

The transmission mechanism of a multimode W-type optical fiber is clarified by the experimental study of the effect of the intermediate layer on the transmission characteristics. It is shown that control of the layer width is an effective means for achieving the desired loss and bandwidth. A W-type fiber with a thick intermediate layer has a transmission loss on the order of 2 dB/km. To determine the transmission characteristics of a W-type fiber applicable to system design, the length dependence of several fiber characteristics is investigated. Concepts such as splices used as mode scramblers and the effect of the intermediate layer as a barrier against OH absorption loss are introduced. The wavelength dependence of microbending loss of a W-type fiber is also described.