US 6,243,522 B1Granted

Photonic crystal fiber

AssigneeCorning Incorporated

InventorsDouglas Clippinger Allan, Nicholas Francis Borrelli, James Conrad Fajardo, Richard Michael Fiacco, Daniel Warren Hawtof, James Andrew West

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Abstract

Disclosed is an optical waveguide fiber preform which is an assembly of one or more core rods surrounded by a plurality of clad rods. The clad rods have a central portion and a surrounding layer, in which the refractive index of the central portion is lower than that of the surrounding layer. The preform is drawn into an optical waveguide fiber that has a two component clad layer. Proper choice of the central portion and surrounding layer provide a waveguide fiber that is endlessly single mode. Alternative embodiments include fibers containing dopants that enhance fiber photosensitivity or which provide stress-induced or asymmetric-refractive-index-induced birefringence in the waveguide fiber.

Claims34

Dependent claims

An optical waveguide fiber preform comprising:

a core body having a longitudinal axis and an effective refractive index;
a plurality of clad rods, each clad rod having a longitudinal axis, and including a central portion, and a layer surrounding the central portion;
wherein the refractive index of the central portion is different from the refractive index of the layer surrounding the central portion by a pre-selected amount and the clad rod diameters are pre-selected;
and,
wherein the plurality of clad rods are held in position about the core body to form an assembly comprising a layer of clad rods surrounding the core body;
and,
wherein the pre-selected amount of difference between the respective refractive indexes of the clad rod central portion and the clad rod surrounding layer provides an effective refractive index of the layer of clad rods that is less than the effective refractive index of the core body.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/434,364Filed 5 Nov 1999 · us provisional application
Priority: 21 Dec 1998
Granted: 5 Jun 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

G02B 6/02338
Characterised by core or core-cladding interface features: structured core, e.g. core contains more than one material, non-constant refractive…
C03B 37/01205
Manufacture of preforms for drawing fibres or filaments: starting from tubes, rods, fibres or filaments
C03B 37/028
From reheated softened tubes, rods, fibres or filaments , e.g. drawing fibres from preforms: drawing fibre bundles, e.g. for making fibre bundles…
G02B 6/02347
Characterised by cladding features, i.e. light confining region: longitudinal structures arranged to form a regular periodic lattice, e.g.…