Barbell optical fiber and method of making the same

A method of making a high aspect ratio core optical fiber preform comprising:

• providing an outer mold;
• inserting an inner mold within an opening in the outer mold, the inner mold exhibiting a barbell configuration including a near-net rectangular shape having an elongated cross-section with a wide slow axis dimension and a narrow fast axis direction with a pair of near-net shapes adjacent to each fast axis edge of the near-net rectangular shape;
• placing cladding material of a first composition in open areas between the outer mold and the inner mold;
• removing the inner mold;
• inserting a near-net rectangular shape core region of a second composition, and having an elongated cross-section with a wide slow axis dimension and a narrow fast axis direction, in the opening created by removing the inner mold;
• and
• inserting a pair of near-net shape elements having a third composition at opposing end terminations of the slow-axis edges of the near-net rectangular shape core region, forming a pair of edge-cladding regions.

A method of making a high aspect ratio core optical fiber preform, comprising:

• providing a first half of a clam shell mold structure, the first half formed of a first composition and including central longitudinal region and opposing semi-circular regions extending longitudinally along either side thereof;
• disposing a near-net rectangular shape core region on the central longitudinal region, the near-net rectangular shape core region of a second composition and having an elongated cross-section with a wide slow axis dimension and a narrow fast axis direction;
• disposing a pair of near-net shape cladding elements of a third composition within each semi-circular region such that the near-net shape cladding elements contacts the near-net rectangular shape core region;
• and
• covering with a second half of the clam shell mold structure, the second half of the clam shell mold formed of the first composition and including semi-circular regions for encasing the pair of near-net shape cladding elements, the combination of the first and second halves of the clam shell mold forming a cladding region for the high aspect ratio core optical fiber preform.

A high aspect ratio core optical fiber exhibiting a barbell configuration comprising:

• a near-net rectangular shape core region of a first composition, the core region having an elongated cross-section with a wide slow axis dimension and a narrow fast axis direction;
• a pair of near-net shape cladding regions having a second composition, the pair of near-net shape cladding regions disposed adjacent to each fast axis edge of the core so as to contact the edges of the core region, the combination exhibiting a barbell configuration;
• and
• an outer cladding of a third composition disposed to surround the barbell configuration, the third composition being different from the first composition.

A barbell-structure optical fiber, comprising:

• a high aspect ratio core region having an elongated cross-section with a wide slow-axis dimension and a narrow fast-axis dimension, wherein the core region has a substantially rectangular shape in cross-section including a width and a height defining an aspect ratio of width to height, the core region having an aspect ratio at least 10:1, and the core region having a first refractive index;
• an inner cladding region positioned in contact with and sandwiching the core region, the inner cladding having a second refractive index lower than the first refractive index;
• an outer cladding region arranged to surround the inner cladding, the outer cladding region having a third refractive index lower than the second refractive index;
• and
• a first edge-cladding region and a second edge-cladding region, the first edge-cladding region positioned adjacent to a first slow-axis edge region of the core region, the second edge-cladding region positioned adjacent to a second slow-axis edge region of the core region.

A barbell-structure optical fiber, comprising:

• a high aspect ratio core region having an elongated cross-section with a wide slow-axis dimension and a narrow fast-axis dimension, wherein the core region has a substantially rectangular shape in cross-section including a width and a height defining an aspect ratio of width to height, the core region having an aspect ratio at least 10:1, and the core region having a first refractive index;
• an inner cladding region positioned in contact with and sandwiching the core region, the inner cladding having a second refractive index lower than the first refractive index;
• and
• a first edge-cladding region and a second edge-cladding region, the first edge-cladding region positioned adjacent to a first slow-axis edge region of the core region, the second edge-cladding region positioned adjacent to a second slow-axis edge region of the core region.