Fabrication of optical waveguides

• US 4,111,520 A
• Filed: 01/13/1975
• Issued: 09/05/1978
• Est. Priority Date: 01/13/1975
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Bernal G., Enrique
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Levy, Stewart
• Application Number:
  US05/540,920
• Time in Patent Office: 1,331 Days
• Field of Search: 350/96 WG, 350/96.12
• US Class Current: 385/132
• CPC Class Codes: C03B 27/012 by heat treatment, e.g. for crystallisation; Heat treatment of glass products before tempering by cooling C03B27/008, C03B27/016 take precedence
• CPC Class Codes: C03B 32/00 Thermal after-treatment of glass products not provided for in groups C03B19/00 , C03B25/00 - C03B31/00 or C03B37/00, e.g. crystallisation, eliminating gas inclusions or other impurities; Hot-pressing vitrified, non-porous, shaped glass products
• CPC Class Codes: G02B 6/13 Integrated optical circuits characterised by the manufacturing method

Abstract

Optical waveguides are fabricated by heating a region of a body of optical material with an energy beam. The region is locally heated to a temperature at which plastic deformation occurs as a result of the constraints placed by the unheated adjacent material. The plastic strain produced at high temperature translates into a residual stress as the material cools which results in a greater index of refraction within the region than in surrounding regions.

Claims

1. A surface optical waveguide comprising a body of optical material having substrate and surface waveguide regions, the upper surface of the waveguide region being substantially coplanar with a major surface of the material so that the waveguide region extends downwardly from said major surface, the substrate region having a first index of refraction and the surface waveguide region having a second index of refraction, the second index of refraction being greater than the first index of refraction as a result of residual stress within the waveguide region created by laser beam heating of the surface waveguide region, said heating being sufficient to cause plastic deformation within the surface waveguide region, but not sufficient to cause evaportion of the material.

2. A method of forming a surface optical waveguide, in which the upper surface of the waveguide is substantially coplanar with a major surface of a body of optical material, the method comprising heating a surface region of a body of optical material by directing a laser beam onto the surface of the body sufficient to cause plastic deformation within the surface region, but not sufficient to cause evaporation of the optical material, the plastic deformation causing residual stress within the surface region which results in a greater index of refraction within the surface region than in surrounding regions.

3. A method of forming a surface optical waveguide in which the upper surface of the waveguide is substantially coplanar with a major surface of a body of optical material, the method comprising heating a region of the surface of a body of optical material with a laser beam sufficiently to produce a residual stress which increases the refractive index within the surface region, the heating being sufficient to cause plastic deformation within the surface region but not to cause evaporation of the optical material, such that the refractive index within the region is greater than the refractive index of unheated regions of the body.