Graded index waveguide structure and process for forming same

Process for forming a graded index waveguide structure comprising the steps of:

• (a) providing a substrate of fused quartz having a refractive index of about 1.47;
• (b) forming a patterned layer of germanium oxide (GeO.sub.2) having a refractive index of about 1.7 on one surface of said substrate, said pattern being formed in a predetermined geometry and to a thickness in the range of 5 to 10 micrometers;
• (c) forming a layer of silicon dioxide (SiO.sub.2) on said patterned layer of said GeO.sub.2 and on said surface of said substrate to a thickness of approximately 100 micrometers, said SiO.sub.2 having a refractive index of about 1.47;
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• (d) heating said substrate with said patterned layer of said GeO.sub.2 and said layer of said SiO.sub.2 deposited thereon to a temperature of approximately 1400.degree. C. for a period of 5 hours to diffuse said GeO.sub.2 into said substrate and into said layer of said SiO.sub.2 and to thereby form said graded index waveguide structure.

A graded index waveguide structure formed by:

• (a) providing a substrate of a first selected optical material having a chosen index of refraction;
• (b) forming a patterned layer of a second selected optical material on one surface of said substrate, said second selected optical material having an index of refraction which is larger than said index of refraction of said first selected optical material of said substrate, and said pattern being formed in a predetermined geometry and to a predetermined thickness;
• (c) forming a layer of a third selected optical material on said patterned layer of said second optical material and on said surface of said substrate to a predetermined thickness, said third optical material having an index of refraction substantially the same as said index of refraction of said first optical material;
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• (d) heating said substrate with said patterned layer of said second optical material and said layer of said third optical material deposited thereon to an elevated temperature for a period of time sufficient to diffuse said second optical material into said first and third optical materials and to thereby form said graded index waveguide structure.

A graded index waveguide structure formed by:

• (a) providing a substrate of fused quartz having a refractive index of about 1.47;
• (b) forming a patterned layer of germanium oxide (GeO.sub.2) having a refractive index of about 1.7 on one surface of said substrate, said pattern being formed in a predetermined geometry and to a thickness in the range of 5 to 10 micrometers;
• (c) forming a layer of silicon dioxide (SiO.sub.2) on said patterned layer of said GeO.sub.2 and on said surface of said substrate to a thickness of approximately 100 micrometers, said SiO.sub.2 having a refractive index of about 1.47;
• and
• (d) heating said substrate with said patterned layer of said GeO.sub.2 and said layer of said SiO.sub.2 deposited thereon to a temperature of approximately 1400.degree. C. for a period of approximately 5 hours to diffuse said GeO.sub.2 into said substrate and into said layer of said SiO.sub.2 and to thereby form said graded index waveguide structure.

A process for simultaneously forming a plurality of graded index waveguide structures comprising the steps of:

• (a) providing a substrate of a first selected optical material having a chosen index of refraction;
• (b) forming a pattern of cavities in one surface of said substrate, said cavities having a predetermined geometry;
• (c) depositing a second selected optical material into said cavities in said substrate to a predetermined thickness, said second selected optical material having an index of refraction which is larger than said index of refraction of said first selected optical material;
• (d) forming a layer of a third selected optical material on said second selected optical material and on said surface of said substrate to a predetermined thickness, said third optical material having an index of refraction substantially the same as said index of refraction of said substrate;
• and
• (e) heating said substrate with said second selected optical material deposited therein and said layer of said third selected optical material formed thereon to an elevated temperature for a period of time sufficient to diffuse said second selected optical material into said substrate and into said layer of said third selected optical material and to thereby form said plurality of said graded index waveguide structures.