Dispersion characteristics of W-shaped polymer optical fiber

We already proposed a W-shaped POF having an index valley of the refractive index at the core-cladding boundary to minimize the modal dispersion in the POFs, and clarified that the additional modal dispersion compensation effect was provided by the W-shaped index profile in wide g range (the index exponent g is the parameter of the index profile). In this paper, to investigate the relationship between the depth of the index valley and bandwidth properties, we fabricated a high NA W-shaped POF and evaluated its bandwidth performance by comparing with those of the conventional GI POP and low NA W-shaped POP. It was experimentally found that the bandwidth of the high NA W-shaped POP was much higher than that of GI POP and low NA W-shaped POP even if the number of p which described the depth of the index valley was small. However, when the index valley was small enough (p < 1.1), the additional modal dispersion compensation effect was not observed.