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US5299276A Expired / Lapsed US ⏱️ 0.0 years remaining

Waveguide type optical device and method for manufacturing the same

Assignee: Fujitsu Ltd
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Filing: 1992-10-09
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Granted: 1994-03-29
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Expires: 2012-10-09
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Abstract

Abstract A method for fabricating a waveguide type optical device is disclosed, through which a core and a reference plane are obtained at the same time by etching a core layer using a thin layer of a predetermined shape formed on the core layer as a mask. In this waveguide type optical device, the core is easily coupled with an optical element such as an optical fiber by means of the reference plane.

Inventors

  • 👤 Koji Okamura
  • 👤 Tadao Arima

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 22:33
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/132; G02B6/136; G02B6/24; G02B6/26; G02B6/30

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 172 words
A method for fabricating a waveguide optical device comprising the steps of: forming evenly a core layer with a relatively high index of refraction upon an under clad with a relatively low index of refraction; forming a first and second thin film layers upon said core layer in a core forming region and a reference plane forming region in the vicinity of the core forming region, respectively, said thin film layers having a sufficiently lower etching rate than the etching rate of said core layer; etching said core layer with said first and second thin film layers used as masks, thereby forming a core and a reference plane, respectively; removing said first thin film layer on the core; forming an outer clad with a relatively low index of refraction of a material having a sufficiently higher etching rate than the etching rate of said second thin film layer so as to cover at least said core; and partially etching said outer clad to expose at least a part of said reference plane.
Claim 2
Independent Claim 172 words
A method for fabricating a waveguide optical device comprising the steps of: forming evenly a core layer with a relatively high index of refraction upon an under clad with a relatively low index of refraction; forming a first and second thin film layers upon said core layer in a core forming region and a reference plane forming region in the vicinity of the core forming region, respectively, said thin film layers having a sufficiently lower etching rate than the etching rate of said core layer; etching said core layer with said first and second thin film layers used as masks, thereby forming a core and a reference plane, respectively; removing said first thin film layer on the core; forming an outer clad with a relatively low index of refraction of a material having a sufficiently higher etching rate than the etching rate of said second thin film layer so as to cover at least said core; and partially etching said outer clad to expose at least a part of said reference plane.
Claim 3
Dependent Claim 50 words
A method according to claim 1, wherein said under clad, said core layer, and said outer clad are formed by heating and vitrifying oxide glass soot whose main component is SiO 2 precipitated by flame hydrolysis; and said first and second thin film layers are formed by sputtering of Si.
Claim 4
Dependent Claim 41 words
A method according to claim 2, further comprising the steps of: forming an intermediate layer whose main component is SiO 2 between said core and said outer clad by chemical vapor deposition; and annealing said intermediate layer by heating the same.
Claim 5
Dependent Claim 21 words
A method according to claim 3, wherein said intermediate layer has a thickness within the range from 0.5 to 2 μm.
Claim 6
Dependent Claim 24 words
A method according to claim 3, wherein the material gas used in said chemical vapor deposition contains Si(OC 2 H 5 ) 4 .
Claim 7
Dependent Claim 29 words
A method according to claim 3, wherein said annealing is performed at a temperature equal to or higher than the heating temperature at which said outer clad is formed.
Claim 8
Dependent Claim 20 words
A method according to claim 3, wherein said annealing is performed under a low pressure or in an He atmosphere.
Claim 9
Dependent Claim 19 words
A method according to claim 3, wherein said core constitutes an optical coupling portion of a directional optical coupler.
Claim 10
Dependent Claim 16 words
A method according to claim 2, wherein said under clad is formed on a Si substrate.
Claim 11
Dependent Claim 91 words
A method according to claim 1, further comprising the steps of: fixing an optical element to a guide of a predetermined form having a plane surface to be brought into close contact with said reference plane; and optically coupling said optical element to said core while said plane surface is in close contact with said reference plane; wherein said guide is so formed that the optical axis of said optical element aligns with the optical axis of said core when said plane surface is in close contact with said reference plane.
Claim 12
Dependent Claim 14 words
A method according to claim 10, wherein said optical element is an optical fiber.
Claim 13
Dependent Claim 37 words
A method according to claim 1, wherein two of said second thin film layers are formed on both sides of said first thin film layer so as to face each other across said first thin film layer.
Claim 14
Dependent Claim 98 words
A waveguide optical device comprising: an under clad with a relatively low index of refraction; a core with a relatively high index of refraction formed on said under clad; an outer clad with a relatively low index of refraction formed so as to cover said core; and a thin film layer formed in the vicinity of said core on the same plane with the bottom face of said core or on the same plane with the top face of said core; wherein the top face of said thin film layer is exposed to serve as a reference plane.
Claim 15
Dependent Claim 98 words
A waveguide optical device comprising: an under clad with a relatively low index of refraction; a core with a relatively high index of refraction formed on said under clad; an outer clad with a relatively low index of refraction formed so as to cover said core; and a thin film layer formed in the vicinity of said core on the same plane with the bottom face of said core or on the same plane with the top face of said core; wherein the top face of said thin film layer is exposed to serve as a reference plane.
Claim 16
Dependent Claim 35 words
A waveguide optical device according to claim 13 wherein the main component of said under clad, said core, and said outer clad is SiO 2 and the material of said thin film layer is Si.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-03-28 1997-09-27 1998-03-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-03-28 2001-09-27 2002-03-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-03-28 2005-09-27 2006-03-29 $7700.00 Window Closed / Lapsed

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