Coupling optical fibre to waveguide

Apparatus for coupling an optical fibre to a waveguide on an optical chip, the apparatus comprising a recess in the chip for receiving the optical fibre, the recess comprising a V-groove the side faces of which locate the position of the fibre in directions perpendicular to the optical axis of the fibre so as to position the fibre in alignment with the waveguide, and an end face adjacent the end of the waveguide, the end face of the recess being substantially flat and substantially perpendicular to the plane of the chip with its normal inclined to the optical axis of the waveguide so an optical fibre having an inclined end face can be brought into a close, abutting relationship with the end of the waveguide and brought into rotational alignment therewith about its optical axis by positioning the fibre so its inclined end face lies in planar contact with the end face of the recess, wherein the recess comprises two portions, a first portion which includes the V-groove and a second portion which includes said end face, and wherein the second portion of the recess has a length, in a direction parallel to the axis of the locating means, of at least 0.35 and preferably in the range 0.35 to 0.5 times the diameter of the optical fibre.

Apparatus for coupling an optical fibre to a waveguide on an optical chip, the apparatus comprising a recess in the chip for receiving the optical fibre, the recess comprising a V-groove the side faces of which locate the position of the fibre in directions perpendicular to the optical axis of the fibre so as to position the fibre in alignment with the waveguide, and an end face adjacent the end of the waveguide, the end face of the recess being substantially flat and substantially perpendicular to the plane of the chip with its normal inclined to the optical axis of the waveguide so an optical fibre having an inclined end face can be brought into a close, abutting relationship with the end of the waveguide and brought into rotational alignment therewith about its optical axis by positioning the fibre so its inclined end face lies in planar contact with the end face of the recess, wherein the recess comprises two portions, a first portion which includes the V-groove and a second portion which includes said end face, and wherein the first portion of the recess is formed by a wet etching process and the second portion of the recess is formed by a dry etching process.

Apparatus for coupling an optical fibre to a waveguide on an optical chip, the apparatus comprising a recess in the chip for receiving the optical fibre, the recess comprising a V-groove the side faces of which locate the position of the fibre in directions perpendicular to the optical axis of the fibre so as to position the fibre in alignment with the waveguide, and an end face adjacent the end of the waveguide, the end face of the recess being substantially flat and substantially perpendicular to the plane of the chip with its normal inclined to the optical axis of the waveguide so an optical fibre having an inclined end face can be brought into a close, abutting relationship with the end of the waveguide and brought into rotational alignment therewith about its optical axis by positioning the fibre so its inclined end face lies in planar contact with the end face of the recess, wherein the recess comprises two portions, a first portion which includes the V-groove and a second portion which includes said end face, the depth of the second portion being at least as great as the depth of the first portion.