Splittable fiber optical waveguide and method of manufacture

Claim 3

A method according to claim 1, wherein the step of providing a splittable optical fiber waveguide comprises forming a preform having a longitudinally extending indentation in an outer surface thereof for each of the longitudinal indentations of the surface of the waveguide and subsequently drawing the fiber from said preform.

Claim 4

A method according to claim 2, which includes a step of notching each indentation after the step of drawing and before the step of pressing wedges to ensure the desired depth of each indentation.

Claim 5

A method according to claim 2, wherein the step of forming the preform with the longitudinal indentations includes utilizing a double crucible method of forming the preform and includes providing the nozzle on the exterior crucible with a shape to form the indentations in the outer surface of the material drawn through the exterior nozzle.

Claim 6

A method according to claim 2, wherein the step of forming the preform includes providing a rod shaped preform and subsequently sawing the longitudinally extending indentations in an outer surface thereof.

Claim 7

A method according to claim 2, wherein the step of forming the preform includes providing a rod shaped preform and subsequently etching the indentations into an outer surface thereof.

Claim 8

An optical device such as an optical directional coupler comprising a splittable optical fiber waveguide with a split portion, said waveguide having an outer surface and at least one fiber optical core being surrounded by a cladding material, said splittable waveguide having at least a pair of longitudinally extending indentations in an outer surface, each of said indentations having a substantial depth with a corresponding reduction in the thickness of the cladding at each indentation to create starting points for splitting wedges and to receive the splitting wedges and said split portion of the waveguide extending between the pair of indentations.

Claim 9

An optical device such as an optical directional coupler comprising a splittable optical fiber waveguide with a split portion, said waveguide having an outer surface and at least one fiber optical core being surrounded by a cladding material, said splittable waveguide having at least a pair of longitudinally extending indentations in an outer surface, each of said indentations having a substantial depth with a corresponding reduction in the thickness of the cladding at each indentation to create starting points for splitting wedges and to receive the splitting wedges and said split portion of the waveguide extending between the pair of indentations.

Claim 10

An optical device according to claim 7, wherein the optical fiber waveguide has at least two fiber optical cores arranged with the split portion extending therebetween.

Claim 11

A splittable optical waveguide especially adapted for use as an optical directional coupler, said waveguide having several fiber optical waveguide cores surrounded by a cladding material, said splittable waveguide having at least two longitudinally extending indentations in an outer surface lying in a plane which passes between two adjacent cores and extends perpendicular to a plane formed by the two adjacent cores, each of said indentations having a sufficient depth with a corresponding reduction in the thickness of the cladding at each indentation to create starting points for splitting wedges and to receive splitting wedges to form a split between said indentations.

Claim 12

A splittable optical waveguide especially adapted for use as an optical directional coupler, said waveguide having several fiber optical waveguide cores surrounded by a cladding material, said splittable waveguide having at least two longitudinally extending indentations in an outer surface lying in a plane which passes between two adjacent cores and extends perpendicular to a plane formed by the two adjacent cores, each of said indentations having a sufficient depth with a corresponding reduction in the thickness of the cladding at each indentation to create starting points for splitting wedges and to receive splitting wedges to form a split between said indentations.