| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide band plastic optical fiber(POF) with a small transmission loss large in numerical aperture with an excellent wet heat resisting characteristic by making the refractive index of a center part highest, and lowering the refractive index gradually toward the outer peripheral part. SOLUTION: A plastic optical fiber(POF) is of multilayer structure formed by concentrically laminating independent polymers HP1, HP2,...HPn respectively manufactured of two or more kinds of vinyl monomers M1, M2,...Mn (n is an integer of 2 or more) and gradually lowered in the refractive index and a (co)polymer with the glass transition temperature (Tg) of 80 deg.C or higher, selected from a group of one or more kinds of binary copolymers CP of the above-mentioned monomers. The refractive index of a center part is made highest, and the refractive index is gradually lowered toward an outer peripheral part. This POF of multilayer structure is of structure formed of nonmixed layers (LNB) with thickness TNB and mixed layers (LB) with thickness TB, or structure formed of only the nonmixed layers (LNB). This results in obtaining the wide band POF with a small transmission loss large in numerical aperture with an excellent wet heat resisting characteristic. |
