Graded index type optical fibers and method of making the same

A method of making a graded index type optical fiber, which comprises:

• preparing a plurality of spinning materials having different refractive indices, each of said spinning materials being made of one (co)polymer, by using (co)polymers selected from the group consisting of two or more (homo)polymers HP1, HP2, . . . Hpn, wherein n is an integer of 2 or greater, derived from monomers M1, M2, . . . , Mn, respectively, and having refractive indices decreasing in that order, and one or more copolymers derived from said monomers;
• feeding said spinning materials to a multilayer concentric circular nozzle so that the refractive index decreases toward the outer periphery, and thereby extruding them through the nozzle;
• and
• allowing the polymers to interdiffuse between adjacent layers of the fiber within said nozzle, after extrusion from the nozzle or within the nozzle and after the polymer material is extruded from the nozzle.

A method of making a graded index type optical fiber, which comprises:

• preparing a plurality of spinning materials having different refractive indices, each of said spinning materials being made of one (co)polymer, each of said spinning materials containing a (co)polymer selected from the group consisting of two or more (homo)polymers HP1, HP2, . . . Hpn, wherein n is an integer of 2 or greater, derived from monomers M1, M2, . . . , Mn, respectively, and having refractive indices decreasing in that order, and one or more copolymers derived from said monomers, and further containing monomer mixtures having the same composition as each of said (co)polymer, and a photopolymerization initiator;
• feeding said spinning materials to a multilayer concentric circular nozzle so that the refractive index decreases toward the outer periphery, and thereby extruding them through the nozzle;
• and
• allowing said monomers to interdiffuse between adjacent layers of the fiber;
• and
• photopolymerizing said monomers.

A method of making a graded index type optical fiber, which comprises:

• preparing a plurality of spinning materials having different refractive indices, each of said spinning materials being made of one (co)polymer, by using (co)polymers selected from the group consisting of three or more (homo)polymers HP1, HP2, . . . Hpn, wherein n is an integer of 3 or greater, derived from monomers M1, M2, . . . , Mn, respectively, and having refractive indices decreasing in that order, and one or more copolymers derived from said monomers;
• feeding said spinning materials to a multilayer concentric circular nozzle so that the refractive index decreases toward the outer periphery, and thereby extruding them through said nozzle;
• and
• allowing the polymers to interdiffuse between adjacent layers of the fiber within said nozzle, after extrusion from the nozzle or within the nozzle and after the polymer material is extruded from the nozzle.