Lensed optical fiber having high coupling efficiency, process of production and apparatus for production of same, and laser diode module
AssigneeFurukawa Electric Co., Ltd.
InventorsXu Jie, Kenji Suzuki, Takayuki Andou
Life of this patent
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Abstract
A lensed optical fiber comprised of an optical fiber having a core and a cladding and a lens portion formed at its front end, a process of production of a lensed optical fiber, an apparatus for its production, and a laser diode module. The lens portion of the lensed optical fiber is comprised of a substantially flat portion formed at an end face of the core, slanting faces formed at an end face of the cladding, and convex curved faces including part of the core between the substantially flat portion and slanting faces.
Claims19
A lensed optical fiber comprising an optical fiber having a core and a cladding and a lens portion formed on a front end of the optical fiber,
- wherein the lens portion has a substantially flat portion formed at an end face of the core, slanting faces formed at an end face of the cladding, and convex curved faces including part of the core formed between the substantially flat portion and the slanting faces,
- wherein said substantially flat portion has a width and diameter each of which is 0.2 to 0.6 times a core diameter and each of which is at least 1 μm, and
- wherein said substantially flat portion has an average radius of curvature of at least 10 times a radii of curvature of said convex curved faces.
A process of production of a lensed optical fiber which comprises an optical fiber having a core and a cladding and a lens portion formed on a front end of the optical fiber, wherein the lens portion has a substantially flat portion formed at an end face of the core, slanting faces formed at an end face of the cladding, and convex curved faces including part of the core formed between the substantially flat portion and the slanting faces, said process comprising:
- a step A of forming a planar portion substantially perpendicular to a core center axis at the front end of the optical fiber,
- a step B of forming said slanting faces around said planar portion, and
- a step C of processing ridge portions of said planar portion and said slanting faces to form said convex curved faces, and polishing said planar portion to form said substantially flat portion.
A laser diode module comprising a laser diode and a lensed optical fiber optically coupled with said laser diode,
- wherein said lensed optical fiber comprises an optical fiber having a core and a cladding and a lens portion formed on a front end of the optical fiber,
- wherein the lens portion has a substantially flat portion formed at an end face of the core, slanting faces formed at an end face of the cladding, and convex curved faces including part of the core formed between the substantially flat portion and the slanting faces,
- wherein said substantially flat portion has a width and diameter each of which is 0.2 to 0.6 times a core diameter and each of which is at least 1 μm, and
- wherein said substantially flat portion has an average radius of curvature of at least 10 times a radii of curvature of said convex curved faces.
Dependencies are inferred from the claim text.