Multicore hollow optical fiber and a method for preparation thereof
AssigneeAsahi Kasei Kogyo Kabushiki Kaisha
InventorShinichi Teshima
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Abstract
The present invention relates to a multicore hollow optical fiber comprising a hollow central part and a plastic peripheral part, more particularly, a multicore hollow optical fiber having a cross-section of the peripheral part wherein (a) an islands-in-sea structure is formed; (b) the islands comprise a core resin having at least higher refractive index than a cladding resin; (c) the sea comprises a cladding resin or the third resin; (d) the core resin is surrounded by the cladding resin; and (e) voids do not substantially exist; and also having, in the direction of the axis, the above cross-section continuously from one end to the other.
Claims10
A multicore hollow optical fiber comprising a hollow central part and a plastic peripheral part, wherein a cross-section of the peripheral part has (a) an islands-in-sea structure;
- (b) islands comprising a core resin having at least higher refractive index than a cladding resin;
- (c) a sea comprising the cladding resin or a third resin;
- (d) the core resin surrounded by the cladding resin;
- and (e) no substantial voids;
- and the multicore hollow optical fiber having, in the direction of the axis of the multicore hollow optical fiber, approximately the same cross-section of the peripheral part continuously from one end to the other end of the multicore hollow optical fiber.
A method for preparing a multicore hollow optical fiber, which comprises feeding a melted core resin having a higher refractive index than a cladding resin and a melted cladding resin in a composite spinning die;
- extruding the core resin from a die plate to form a linear core;
- extruding the cladding resin so as to surround the linear core to form an islands-in-sea structure wherein the core constitutes islands and the cladding constitutes a sea in a cross-section of the multicore hollow optical fiber;
- introducing fluid into a central part of the islands-in-sea structure to form a hollow;
- and drawing the islands-in-sea structure having the hollow to a desired diameter while cooling.
A method for preparing a multicore hollow optical fiber, which comprises feeding a melted core resin having a higher refractive index than a cladding resin, a melted cladding resin and a melted third resin in a composite a pinning die;
- extruding the core resin from a die plate to form a linear core;
- extruding the cladding resin so as to surround the linear core;
- extruding the melted third resin so as to surround the linear core which is surrounded by the cladding resin to form an islands-in-sea structure wherein the core and the cladding constitute islands and the third resin constitutes a sea in a cross-section of the multicore hollow optical fiber;
- introducing fluid into a central part of the islands-in-sea structure to form a hollow;
- and drawing the islands-in-sea structure having a hollow to a desired diameter while cooling.
Dependencies are inferred from the claim text.