US4737015A
Expired / Lapsed
US
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Optical waveguide having a silicon oxi-nitride layer
Assignee: HITACHI Ltd HITACHI CABEL
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Filing: 1984-11-26
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Granted: 1988-04-12
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Expires: 2004-11-26
Abstract
Abstract An optical waveguide comprising a layer formed on a substrate, having a mixed composition of silicon oxide and silicon nitride and having an arbitrary value of refractive index ranging between those of the silicon oxide and the silicon nitride. The layer of said mixed composition can be formed on the substrate to easily fabricate the optical waveguide of the present invention by conducting a sputtering method employing a Si target and controlling the composition of a sputtering gas composed of a mixture of N2 and O2 gases.
Inventors
- 👤 Koji Ishida
- 👤 Hiroyoshi Matsumura
- 👤 Kenji Hiruma
- 👤 Kazuyuki Nagatsuma
- 👤 Akihito Hongo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:32
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/132; G02B6/122
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
52 words
A thin-film type optical waveguide comprising: a substrate; and a lower clad, a core and an upper clad provided on said substrate; wherein at least a portion of at least one of said lower clad, said core and said upper clad is an oxi-nitride layer made of silicon oxide and silicon nitride.
Claim 2
Dependent Claim
52 words
A thin-film type optical waveguide comprising: a substrate; and a lower clad, a core and an upper clad provided on said substrate; wherein at least a portion of at least one of said lower clad, said core and said upper clad is an oxi-nitride layer made of silicon oxide and silicon nitride.
Claim 3
Dependent Claim
28 words
A thin-film type optical waveguide as set forth in claim 1, wherein at least said upper clad is an oxi-nitride layer made of silicon oxide and silicon nitride.
Claim 4
Dependent Claim
33 words
A thin-film type optical waveguide as set forth in claim 1, wherein each of at least said core and said upper clad is an oxi-nitride layer made of silicon oxide and silicon nitride.
Claim 5
Dependent Claim
34 words
A thin-film type optical waveguide as set forth in claim 1, wherein each of said lower clad, said core and said upper clad is an oxi-nitride layer made of silicon oxide and silicion nitride.
Claim 6
Dependent Claim
31 words
A thin-film type optical waveguide as set forth in claim 4, wherein said core is an oxi-nitride layer containing more nitrogen than each of said lower clad and said upper clad.
Claim 7
Dependent Claim
63 words
A thin-film type optical waveguide as set forth in claim 1, wherein said oxi-nitride layer has a nitrogen content having a graded distribution in a direction of thickness, the nitrogen content of said oxi-nitride layer being higher in an interior portion of said layer than at surfaces of said oxi-nitride layer and reaching a maximum at an interior portion of said oxi-nitride layer.
Claim 8
Dependent Claim
62 words
A thin-film type optical waveguide as set forth in claim 6, where in said oxi-nitride layer has a graded refractive index distribution in a direction of thickness, the refractive index of said oxi-nitride layer being higher in an interior portion of said layer than at surfaces of said oxi-nitride layer and reaching a maximum at an interor portion of said oxi-nitride layer.
Claim 9
Dependent Claim
33 words
A thin-film type optical waveguide as set forht in claim 2, wherein said upper clad is made of an oxi-nitride layer having a refractive index lower than a refractive index of said core.
Claim 10
Dependent Claim
56 words
A thin-film type optical waveguide as set forth in claim 3, wherein said core is made of an oxi-nitride layer having a refractive index higher than a refractive index of said lower clad, and said upper clad is made of an oxi-nitride layer having a refractive index lower than said index of refraction of said core.
Claim 11
Dependent Claim
37 words
A thin-film type optial waveguide as set forth in claim 1, wherein said lower clad is provided on said substrate, said core is provided on said lower clad and said upper clad is provided on said core.
Claim 12
Dependent Claim
32 words
A thin-film type optical waveguide as set forth in claim 8, wherein said substrate and lower clad are made of LiNbO 3 and said core is made of Ti-diffused LiNbO 3 .
Claim 13
Dependent Claim
26 words
A thin-film type optical waveguide as set forth in claim 1, wherein said oxi-nitride layer has a refractive index in the range of 1.458 to 2.230.
Claim 14
Dependent Claim
40 words
A thin-film type optical waveguide as set forth in claim 1, wherein said oxi-nitride layer is formed by a sputtering method employing a Si target and using a sputtering gas containing N 2 and O 2 in a predetermined ratio.
Claim 15
Dependent Claim
20 words
A thin-film type optical waveguide as set forth in claim 1, wherein said core has a thickness of several microns.
Claim 16
Dependent Claim
20 words
A thin-film type optical waveguide as set forth in claim 1, wherein said core has a thickness of about 2.3μm.
Claim 17
Dependent Claim
20 words
A thin-film type optical waveguide as set forth in claim 11, wherein said core has a thickness of several microns.
Claim 18
Dependent Claim
20 words
A thin-film type optical waveguide as set forth in claim 11, wherein said core has a thickness of about 2.3μm.
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) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |