Modal Bandwidth Enhancement of Plastic Optical Fibers by W-Shaped Index Profile and Low-Dispersion Fluorinated Polymer

摘要

In recent years, silica based multimode fibers (MMFs) have been utilized for PMD of Gigabit Ethernet and 10 Gigabit Ethernet to take advantage of the large core diameter. On the other hand, plastic optical fibers (POFs) are expected to be utilized as media for office and home networks, because its large core (100 ～ 500μm) and great mechanical flexibility allow for easy handling, consequently, easy network installation. We have proposed a high-bandwidth graded-index (GI) POF that has a quadratic refractive index profile in the core region, and have demonstrated its high-bandwidth performance by forming an optimum refractive index profile. In this paper, modal bandwidth enhancement in POF is achieved experimentally by two approaches: designing a new index profile, W-shaped profile and employing a fluorinated polymer with low material dispersion. We investigate the bandwidth performances of W-shaped POFs with different index profiles, then, verify that the index valley in W-shaped index profile affects the group delay of higher-order modes particularly. We design the desired depth of the index valley in W-shaped index profiles for the first time. Using a fluorinated polymer with low material dispersion, the highest bandwidth would be achieved by the W-shaped index profile.