US 5,028,246 A · Methods of making optical waveguides

Abstract

Low attenuation, low dispersion of optical waveguides are provided by a process initiating with axial deposition of a high velocity core soot stream impinging on a target at a high angle of incidence relative to the axis of rotation of the target. A core cylinder is built up axially by relative movement between the soot stream and target during deposition, the movement being non-constant in order to maintain a substantially constant diameter with a constant deposition rate. A cladding layer is then built up by deposition of soot radially on the core. Subsequent drying and sintering provides a vitreous preform which may be drawn directly into optical waveguides. Alternatively, the sintered product may be drawn down to smaller rods, which then are covered with further deposited soot cladding to a desired final thickness, and after further drying and sintering may be drawn to optical waveguides.

Claims14

Dependent claims

The method of making optical waveguide fibers having attenuation of less than 1 dB/km, low dispersion and relatively low cost comprising the steps of:

depositing core soot material on a rotating target element by directing a stream of the core soot material upwardly against the target element at an angle of greater than 60.degree. to the axis of rotation, the stream having a velocity such that the Reynolds number is greater than 100;
varying the positional relationship between the stream and the deposition surface while maintaining the angle of the stream to the axis of rotation to develop a substantially uniform density cylindrical soot core having a substantially uniform diameter in the range of 5-50 mm until a predetermined length is established;
exhausting core soot material that bypasses the deposition surface upwardly from the region of the cylindrical soot core as the soot core is built up;
depositing cladding soot material on the outer surface of the cylindrical core with a radial stream of cladding soot material to provide a cladding layer coextensive with the core soot cylinder;
drying and sintering the product thus formed;
and
drawing the dried and sintered product into optical waveguide fibers.

4 more elements

The method of making optical waveguide fibers having attenuation of less than 1 dB/km, low dispersion and relatively low cost comprising the steps of:

depositing core soot material on a rotating target element by directing a stream of the core soot material upwardly against the target element at an angle of greater than 60.degree. to the axis of rotation, the axis of rotation being substantially horizontal, the stream having a velocity such that the Reynolds number is greater than 100;
varying the positional relationship between the stream and the deposition surface while maintaining the angle of the stream to the axis of rotation to develop a substantially uniform density cylindrical soot core having a free end and a substantially uniform diameter in the range of 5-50 mm until a predetermined length is established,
the impingement area of the core soot stream being on the free end of the core cylinder and positioned to build up a convex free end and the impingement area being off center relative to the geometric center of the free end
exhausting core soot material that bypasses the deposition surface upwardly from the region of the cylindrical soot core as it is built up;
depositing cladding soot material on the outer surface of the cylindrical core with a radial stream of cladding soot material to provide a cladding layer coextensive with the core soot cylinder;
drying and sintering the product thus formed;
and
drawing the dried and sintered product into optical waveguide fibers.

5 more elements

Dependencies are inferred from the claim text.

Methods of making optical waveguides

Life of this patent

Methods of making optical waveguides

Life of this patent

Abstract

Claims14