US3934061A — Method of forming planar optical waveguides

Claim 1

Independent Claim 417 words

A method of forming a planar optical waveguide for light propagation comprising the steps of: providing a substantially flat glass substrate having a predetermined desired index of refraction, applying a first coating of glass having an index of refraction greater than that of said glass substrate to at least a portion of one flat surface of said substrate to thereby form a film thereon, said first coating of glass having an outer exposed surface substantially parallel to said one flat surface of said substrate, the thickness of said first coating being defined by said surfaces, the width of said first coating being the dimension perpendicular to both said thickness and the light propagation axis of said first coating, and applying a second coating of glass having an index of refraction less than that of said first coating of glass over at least said outer exposed surface of said first coating of glass to thereby form a film thereon, the thickness of said first coating of glass for any desired finite width thereof being equal to or less than the thickness a of a coating having an infinite width, thickness a being determined in accordance with one of the following equations for TM Om modes where m is an even integer ##EQU13## for TM Om modes where m is an odd integer ##EQU14## for TE Om modes where m is an even integer ##EQU15## for TE Om modes where m is an odd integer ##EQU16## where m ≦ 10 and is the highest mode order to be propagated within a waveguide the first coating of which has a thickness a and an infinite width, λ is the wavelength of light to be propagated within said waveguide the first coating of which has a thickness a and an infinite width, n 2 is the index of refraction of said first coating, and one of n 1 and n 3 being the index of refraction of said substrate while the other of n 1 and n 3 being the index of refraction of said second coating of glass, said thickness of said first coating of glass being so determinable where the propagation constant of said waveguide is equal to or less than K 1 , where K 1 is greater than K 3 , where K.sub.1 = 2πn.sub.1 /λ, and K.sub.3 = 2πn.sub.3 /λ the thickness of each said substrate and said second coating of glass being at least about two times the thickness of said first coating of glass.

Claim 2

Independent Claim 417 words

A method of forming a planar optical waveguide for light propagation comprising the steps of: providing a substantially flat glass substrate having a predetermined desired index of refraction, applying a first coating of glass having an index of refraction greater than that of said glass substrate to at least a portion of one flat surface of said substrate to thereby form a film thereon, said first coating of glass having an outer exposed surface substantially parallel to said one flat surface of said substrate, the thickness of said first coating being defined by said surfaces, the width of said first coating being the dimension perpendicular to both said thickness and the light propagation axis of said first coating, and applying a second coating of glass having an index of refraction less than that of said first coating of glass over at least said outer exposed surface of said first coating of glass to thereby form a film thereon, the thickness of said first coating of glass for any desired finite width thereof being equal to or less than the thickness a of a coating having an infinite width, thickness a being determined in accordance with one of the following equations for TM Om modes where m is an even integer ##EQU13## for TM Om modes where m is an odd integer ##EQU14## for TE Om modes where m is an even integer ##EQU15## for TE Om modes where m is an odd integer ##EQU16## where m ≦ 10 and is the highest mode order to be propagated within a waveguide the first coating of which has a thickness a and an infinite width, λ is the wavelength of light to be propagated within said waveguide the first coating of which has a thickness a and an infinite width, n 2 is the index of refraction of said first coating, and one of n 1 and n 3 being the index of refraction of said substrate while the other of n 1 and n 3 being the index of refraction of said second coating of glass, said thickness of said first coating of glass being so determinable where the propagation constant of said waveguide is equal to or less than K 1 , where K 1 is greater than K 3 , where K.sub.1 = 2πn.sub.1 /λ, and K.sub.3 = 2πn.sub.3 /λ the thickness of each said substrate and said second coating of glass being at least about two times the thickness of said first coating of glass.

Claim 3

Dependent Claim 45 words

The method of claim 1 wherein said first coating of glass is formed by the steps comprising: depositing a layer of glass soot on at least a portion of one flat surface of said substrate by flame hydrolysis, and heating said soot until it sinters.

Claim 4

Dependent Claim 57 words

The method of claim 2 wherein said second coating of glass is formed by the steps comprising: depositing a second layer of glass soot over at least said outer exposed surface of said first coating by flame hydrolysis, and heating said first coating and said second layer of glass soot until said second layer of soot sinters.

Claim 5

Dependent Claim 88 words

The method of claim 1 wherein said first and second coatings of glass are formed by the steps comprising: depositing a first layer of doped fused silica soot over at least a portion of one flat surface of said substrate by flame hydrolysis, depositing a second layer of fused silica soot over at least said outer exposed surface of said first soot layer by flame hydrolysis, and heating the structure so formed until said first and second layers of soot sinter forming said first and second coatings respectively.

Claim 6

Dependent Claim 41 words

The method of claim 4 wherein said first coating is fused silica doped with at least one material selected from the group consisting of titanium oxide, tantalum oxide, tin oxide, niobium oxide, zirconium oxide, aluminum oxide, lanthanum oxide, and germanium oxide.

Claim 7

Dependent Claim 23 words

The method of claim 4 wherein said first coating is fused silica doped with not more than 20 percent by weight titanium oxide.

Claim 8

Dependent Claim 22 words

The method of claim 1 wherein the width to thickness ratio of said first coating is equal to or less than ten.

Claim 9

Dependent Claim 19 words

The method of claim 1 wherein the first or second coating of glass is applied by chemical vapor deposition.

Claim 10

Dependent Claim 25 words

The method of claim 1 wherein the first or second coating of glass is formed by applying a glass frit and thereafter sintering said frit.

Claim 11

Dependent Claim 30 words

The method of claim 1 wherein said second coating is fused silica and said first coating is fused silica doped with not more than 40 percent by weight of dopant.

Claim 12

Independent Claim 343 words

A method of forming a planar optical waveguide for light propagation comprising the steps of: providing a substantially flat glass substrate having a predetermined desired index of refraction, applying a first coating of a glass having an index of refraction greater than that of said glass substrate to at least a portion of one flat surface of said substrate to thereby form a film thereon, said first coating of glass having an outer exposed surface substantially parallel to said one flat surface of said substrate, the thickness of said first coating being defined by said surfaces, the width of said first coating being the dimension perpendicular to both said thickness and the light propagation axis of said first coating, and applying a second coating of glass having an index of refraction substantially equal to that of said substrate over at least said outer exposed surface of said first coating of glass to thereby form a film thereon, the thickness of said first coating of glass for any desired finite width thereof being equal to or less than the thickness a of a coating having infinite width, thickness a being determined in accordance with the following equation 2a/λ (n.sub.2.sup.2 - n.sub.1.sup.2).sup.1/2 = m+1, where m ≦ 10 and is the highest mode order to be propagated within a wave-guide the first coating of which has a thickness a and an infinite width, λ is the wavelength of light to be propagated within said waveguide the first coating of which has a thickness a and an infinite width, n 2 is the index of refraction of said first coating, and n 1 is the index of refraction of said substrate and said second coating of glass, said thickness of said first coating of glass being so determinable where the propagation constant of said waveguide is equal to or less than K 1 , where K.sub.1 = 2πn.sub.1 /λ, and the thickness of each said substrate and said second coating of glass being at least about two times the thickness of said first coating of glass.

Claim 13

Independent Claim 343 words

A method of forming a planar optical waveguide for light propagation comprising the steps of: providing a substantially flat glass substrate having a predetermined desired index of refraction, applying a first coating of a glass having an index of refraction greater than that of said glass substrate to at least a portion of one flat surface of said substrate to thereby form a film thereon, said first coating of glass having an outer exposed surface substantially parallel to said one flat surface of said substrate, the thickness of said first coating being defined by said surfaces, the width of said first coating being the dimension perpendicular to both said thickness and the light propagation axis of said first coating, and applying a second coating of glass having an index of refraction substantially equal to that of said substrate over at least said outer exposed surface of said first coating of glass to thereby form a film thereon, the thickness of said first coating of glass for any desired finite width thereof being equal to or less than the thickness a of a coating having infinite width, thickness a being determined in accordance with the following equation 2a/λ (n.sub.2.sup.2 - n.sub.1.sup.2).sup.1/2 = m+1, where m ≦ 10 and is the highest mode order to be propagated within a wave-guide the first coating of which has a thickness a and an infinite width, λ is the wavelength of light to be propagated within said waveguide the first coating of which has a thickness a and an infinite width, n 2 is the index of refraction of said first coating, and n 1 is the index of refraction of said substrate and said second coating of glass, said thickness of said first coating of glass being so determinable where the propagation constant of said waveguide is equal to or less than K 1 , where K.sub.1 = 2πn.sub.1 /λ, and the thickness of each said substrate and said second coating of glass being at least about two times the thickness of said first coating of glass.

Claim 14

Dependent Claim 88 words

The method of claim 11 wherein said first and second coatings of glass are formed by the steps comprising: depositing a first layer of doped fused silica soot over at least a portion of one flat surface of said substrate by flame hydrolysis, depositing a second layer of fused silica soot over at least said outer exposed surface of said first soot layer by flame hydrolysis, and heating the structure so formed until said first and second layers of soot sinter forming said first and second coatings respectively.

Claim 15

Dependent Claim 41 words

The method of claim 12 wherein said first coating is fused silica doped with at least one material selected from the group consisting of titanium oxide, tantalum oxide, tin oxide, niobium oxide, zirconium oxide, aluminum oxide, lanthanum oxide, and germanium oxide.

Claim 16

Dependent Claim 23 words

The method of claim 12 wherein said first coating is fused silica doped with not more than 20 percent by weight titanium oxide.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-01-19	1979-07-21	1980-01-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-01-19	1983-07-21	1984-01-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-01-19	1987-07-21	1988-01-20	$7700.00	Window Closed / Lapsed

Method of forming planar optical waveguides

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