Patent US4243398A successfully refreshed from Google Patents.
US4243398A
Expired / Lapsed
US
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Method of producing dielectric diffraction gratings or dielectric multilayer interference filters
Assignee: NEC Corp
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Filing: 1979-02-02
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Granted: 1981-01-06
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Expires: 1999-02-02
Abstract
Abstract There is disclosed a method of producing dielectric diffraction gratings. This method comprises (a) preparing a preform by forming one upon another layers of two or more glasses having different refractive indices at a given period, and (b) cutting the preform into flat pieces.
Inventors
- 👤 Hidenori Nomura
- 👤 Hiroshi Honmo
- 👤 Shigeo Matsushita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:52
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/18; G02B5/1847; G02B6/00; G02B6/02; G02B6/02295; G02B6/023
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
87 words
A method of producing dielectric diffraction gratings comprising (a) depositing films of two kinds of glass which differ in refractive index alternately at a given period on the inside wall of or around a tubular or rod-shaped starting member, thereby producing a tubular preform, (b) cutting said preform diametrically, thereby producing a flat member, (c) heating and drawing said flat member until the thickness of said films of glass is reduced to a desired value, and, (d) cutting said drawn member into minute pieces of diffraction gratings.
Claim 2
Independent Claim
87 words
A method of producing dielectric diffraction gratings comprising (a) depositing films of two kinds of glass which differ in refractive index alternately at a given period on the inside wall of or around a tubular or rod-shaped starting member, thereby producing a tubular preform, (b) cutting said preform diametrically, thereby producing a flat member, (c) heating and drawing said flat member until the thickness of said films of glass is reduced to a desired value, and, (d) cutting said drawn member into minute pieces of diffraction gratings.
Claim 3
Independent Claim
82 words
A method of producing dielectric diffraction gratings comprising (a) depositing films of two kinds of glass which differ in refractive index alternately at a given period on the inside wall of or around a tubular or rod-shaped starting member, thereby producing a tubular preform, (b) applying pressure to the interior of said tubular preform, so as to inflate said tubular preform during heating, thereby adjusting the film thickness to a desired value, and (c) cutting from said tubular preforms dielectric diffraction gratings.
Claim 4
Independent Claim
82 words
A method of producing dielectric diffraction gratings comprising (a) depositing films of two kinds of glass which differ in refractive index alternately at a given period on the inside wall of or around a tubular or rod-shaped starting member, thereby producing a tubular preform, (b) applying pressure to the interior of said tubular preform, so as to inflate said tubular preform during heating, thereby adjusting the film thickness to a desired value, and (c) cutting from said tubular preforms dielectric diffraction gratings.
Claim 5
Dependent Claim
37 words
The method of claim 2, wherein said films are prepared from glass materials selected from the group consisting of silicon dioxide and at least one of germanium dioxide, phosphorous oxide and boron oxide as a second component.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |