Two layer coating of an optical waveguide
AssigneeNorthern Telecom Limited
InventorWilliam P. Trumble
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Abstract
Optical conductors, useful in the transmission of data-encoding light beams, that comprise an optically transmissive rod carrying one or more cavities, each with a border defining an inclined planar surface, can be produced via a method comprising the steps of (1) coating the rod, via plasma-assisted physical vapor deposition, with an amorphous material of lower refractive index than the rod's; and (2) rendering each inclined planar surface light-reflective. The sequence of steps (1) and (2) can be reversed.
Claims22
A method for making an optical waveguide element which comprises an optically transmissive rod compound of at least one selected from the group consisting of aryl esters, polycarbonates, polysulfones, carbonates-esters plastic alloys and aromatic ester carbonate copolymers having a predetermined cross sectional area and comprising (A) an external planar surface extending along its length in parallel with the longitudinal axis of said rod and (B) at least one cavity having (1) a longitudinal axis which is transverse to said longitudinal axis of said rod and (2) a border in said rod which defines an inclined planar surface, said method comprising the steps of
- (a) coating said rod by plasma-assisted physical vapor deposition with a layer comprised of an unfused silicon oxide material having a refractive index that is lower than the refractive index of said rod;
- and
- (b) rendering at least said inclined planar surface light-reflective by corrugating said inclined planar surface or coating said inclined planar surface with a light-reflective material.
Dependencies are inferred from the claim text.