US3981707A
Expired / Lapsed
US
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Method of making fluorine out-diffused optical device
Assignee: Corning Glass Works
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Filing: 1975-04-23
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Granted: 1976-09-21
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Expires: 1995-04-23
Abstract
Abstract A fluorine containing silicate glass substrate is heated to a temperature sufficiently high to permit fluorine to out-diffuse from the surface thereof. A surface region is formed having a gradient fluorine concentration in a direction perpendicular to the substrate surface, the region of lowest fluorine concentration having the highest refractive index. The resultant device is capable of functioning as an optical waveguide.
Inventors
- 👤 Roger J. Araujo
- 👤 Nicholas F. Borrelli
- 👤 John D. Crow
- 👤 Thomas P. Seward, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:44
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/028; G02B6/0288; B; B29; B29D; B29D11/00; B29D11/00663; B29D11/00682; C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/01205; C03B37/01225; C03B37/02; C03B37/025; C03B37/027; C03B37/02754; C03C; C03C23/00; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/091; C03B2201/00; C03B2201/06; C03B2201/08; C03B2201/12; C03B2201/14; C03B2201/30; C03B2201/32; C03B2201/50; C03B2203/00; C03B2203/10; C03B2203/22; C03B2205/00; C03B2205/12; C03B2205/16; Y; Y10; Y10S; Y10S65/00; Y10S65/15; Y10S65/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
148 words
A method of forming a planar optical waveguide comprising the steps of providing a flat substrate of transparent silicate glass containing an amount of fluorine effective to decrease the refractive index thereof to a value below that of the silicate glass alone, polishing a surface of said substrate to form an optical quality surface, and heating said substrate to a temperature below the softening point temperature but greater than the annealing point temperature of said silicate glass, said temperature being sufficiently high to effect an out-diffusion of fluorine from said surface to form at said surface a layer of reduced fluorine content, the concentration of fluorine in said layer gradually increasing from a minimum value at said surface to a maximum value within said substrate so that the refractive index of said layer decreases from a maximum value at said surface to a minimum value within said substrate.
Claim 2
Independent Claim
148 words
A method of forming a planar optical waveguide comprising the steps of providing a flat substrate of transparent silicate glass containing an amount of fluorine effective to decrease the refractive index thereof to a value below that of the silicate glass alone, polishing a surface of said substrate to form an optical quality surface, and heating said substrate to a temperature below the softening point temperature but greater than the annealing point temperature of said silicate glass, said temperature being sufficiently high to effect an out-diffusion of fluorine from said surface to form at said surface a layer of reduced fluorine content, the concentration of fluorine in said layer gradually increasing from a minimum value at said surface to a maximum value within said substrate so that the refractive index of said layer decreases from a maximum value at said surface to a minimum value within said substrate.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein said silicate glass contains at least 0.1 weight percent fluorine.
Claim 4
Dependent Claim
40 words
A method in accordance with claim 1 further comprising the step of forming on the surface of said layer of reduced fluorine content a protective layer having a refractive index less than that of said layer of reduced fluorine content.
Claim 5
Independent Claim
270 words
A method of forming a glass optical waveguide fiber having a refractive index distribution throughout its length such that in a plane perpendicular to the fiber optical axis the refractive index progressively decreases from a higher value at the optical axis of the fiber to a lower value at some finite fiber radius, said method comprising providing a hollow tube of transparent silicate glass containing an amount of fluorine effective to decrease the refractive index thereof to a value below that of the silicate glass alone, heating said tube to a temperature below the softening point temperature but greater than the annealing point temperature of said silicate glass, said temperature being sufficiently high to effect an out-diffusion of fluorine from at least the inner surface thereof to create at said inner surface a layer of reduced fluorine content, the concentration of fluorine in said layer gradually increasing from a minimum value at said inner surface to a maximum value within said tube, said fluorine out-diffusion process causing the refractive index of said tube to gradually decrease from a high value at the inner surface of said tube to a lower value within said tube, subjecting said tube to a temperature sufficiently high to permit said tube to be drawn into a fiber, and drawing said tube to collapse the hole in the center thereof and to reduce the cross-sectional area thereof and thereby form a glass optical fiber having a refractive index distribution throughout its length which progressively decreases from a high value at the optical axis of said fiber to a minimum value at some radius within said fiber.
Claim 6
Independent Claim
270 words
A method of forming a glass optical waveguide fiber having a refractive index distribution throughout its length such that in a plane perpendicular to the fiber optical axis the refractive index progressively decreases from a higher value at the optical axis of the fiber to a lower value at some finite fiber radius, said method comprising providing a hollow tube of transparent silicate glass containing an amount of fluorine effective to decrease the refractive index thereof to a value below that of the silicate glass alone, heating said tube to a temperature below the softening point temperature but greater than the annealing point temperature of said silicate glass, said temperature being sufficiently high to effect an out-diffusion of fluorine from at least the inner surface thereof to create at said inner surface a layer of reduced fluorine content, the concentration of fluorine in said layer gradually increasing from a minimum value at said inner surface to a maximum value within said tube, said fluorine out-diffusion process causing the refractive index of said tube to gradually decrease from a high value at the inner surface of said tube to a lower value within said tube, subjecting said tube to a temperature sufficiently high to permit said tube to be drawn into a fiber, and drawing said tube to collapse the hole in the center thereof and to reduce the cross-sectional area thereof and thereby form a glass optical fiber having a refractive index distribution throughout its length which progressively decreases from a high value at the optical axis of said fiber to a minimum value at some radius within said fiber.
Claim 7
Dependent Claim
16 words
The method of claim 4 wherein said silicate glass contains at least 0.1 weight percent fluorine.
Claim 8
Dependent Claim
17 words
A method in accordance with claim 4 wherein the steps of heating and subjecting are simultaneously performed.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-21 | 1980-03-22 | 1980-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-21 | 1984-03-22 | 1984-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-21 | 1988-03-22 | 1988-09-21 | $7700.00 | Window Closed / Lapsed |