US6021239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photocoupler and method for producing the same
Assignee: Hitachi Cable Ltd
•
Filing: 1997-10-29
•
Granted: 2000-02-01
•
Expires: 2017-10-29
Abstract
Abstract A photocoupler according to the present invention includes: an optical waveguide including a substrate, at least a first dielectric layer provided on the substrate, the first dielectric layer having a tapered structure whose thickness varies in an x-direction in which light is propagated after coupling, and a second dielectric layer provided on the first dielectric layer; a light incidence component provided above the optical waveguide, which causes light incident thereon to be directed toward a surface of the optical waveguide at a prescribed angle; and a bonding section for bonding the light incidence component to the optical waveguide. The bonding section has an edge surface which makes contact with the surface of the waveguide in a straight line and has a portion which makes contact with neither the light incidence component nor the surface of the optical waveguide. The tapered structure of the first dielectric layer has a shape set such that a radiation pattern of light with a wavelength λ output from the optical waveguide of the photocoupler fulfills the following expression: a.sub.n-1 (1-r.sub.n)<a.sub.n (1-r.sub.n+1) where α rn is a radiation coefficient at a section X n-1 <X<X n of the first dielectric layer where a thickness thereof varies in a tapering manner; a n is an amplitude at a distance X n from the edge surface of the bonding section; and r n is exp(k 0 α rn ΔX); k 0 is 2π/λ; and ΔX is X n -X n-1 .
Inventors
- 👤 Kohji Minami
- 👤 Yukio Kurata
- 👤 Hisato Uetsuka
- 👤 Hirobumi Ouchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:04
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/34; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
284 words
A photocoupler, comprising: an optical waveguide including a substrate, at least a first dielectric layer provided on the substrate, the first dielectric layer having a tapered structure whose thickness varies in an x-direction in which light is propagated after coupling, and a second dielectric layer provided on the first dielectric layer; a light incidence component provided above the optical waveguide, which causes light incident thereon to be directed toward a surface of the optical waveguide at a prescribed angle; and a bonding section for bonding the light incidence component to the optical waveguide, wherein the bonding section has an edge surface which makes contact with the surface of the waveguide in a straight line and has a portion which makes contact with neither the light incidence component nor the surface of the optical waveguide; and the tapered structure of the first dielectric layer has a shape set such that a radiation pattern of light with a wavelength λ output from the optical waveguide of the photocoupler fulfills the following expression (1): a.sub.n-1 (1-r.sub.n)<a.sub.n (1-r.sub.n+1) expression (1) where m is a radiation coefficient at a section X n-1 <X<X n of the first dielectric layer where a thickness thereof varies in a tapering manner; a n is an amplitude at a distance X n from the edge surface of the bonding section; and r n is exp(k o rn ΔX); k o is 2π/λ; and ΔX is X n -X n-1 ; and wherein: a n-1 is the amplitude at a distance X n-1 from the edge of the bonding section, r n+1 =exp(k o r(n+1) ΔX), r(n+1) is a radiation coefficient at section X n <X<X n+1 , and X n+1 =X n +ΔX.
Claim 2
Dependent Claim
284 words
A photocoupler, comprising: an optical waveguide including a substrate, at least a first dielectric layer provided on the substrate, the first dielectric layer having a tapered structure whose thickness varies in an x-direction in which light is propagated after coupling, and a second dielectric layer provided on the first dielectric layer; a light incidence component provided above the optical waveguide, which causes light incident thereon to be directed toward a surface of the optical waveguide at a prescribed angle; and a bonding section for bonding the light incidence component to the optical waveguide, wherein the bonding section has an edge surface which makes contact with the surface of the waveguide in a straight line and has a portion which makes contact with neither the light incidence component nor the surface of the optical waveguide; and the tapered structure of the first dielectric layer has a shape set such that a radiation pattern of light with a wavelength λ output from the optical waveguide of the photocoupler fulfills the following expression (1): a.sub.n-1 (1-r.sub.n)<a.sub.n (1-r.sub.n+1) expression (1) where m is a radiation coefficient at a section X n-1 <X<X n of the first dielectric layer where a thickness thereof varies in a tapering manner; a n is an amplitude at a distance X n from the edge surface of the bonding section; and r n is exp(k o rn ΔX); k o is 2π/λ; and ΔX is X n -X n-1 ; and wherein: a n-1 is the amplitude at a distance X n-1 from the edge of the bonding section, r n+1 =exp(k o r(n+1) ΔX), r(n+1) is a radiation coefficient at section X n <X<X n+1 , and X n+1 =X n +ΔX.
Claim 3
Dependent Claim
68 words
A photocoupler according to claim 1, wherein the shape of the tapered structure is set such that a taper length t of the tapered structure, a thickness s of the second dielectric layer, a maximum thickness D of the first dielectric layer and a minimum thickness d of the first dielectric layer fulfill the following conditions: 5 [μm]<t<15 [μm], 300 [nm]<s<400 [nm], 540 [nm]<D<600 [nm], 320 [nm]<d<400 [μm].
Claim 4
Dependent Claim
70 words
A photocoupler according to claim 1, wherein a height h of the edge surface of the bonding section from the surface of the optical waveguide is set so as to fulfill the following expression (2): h>2r.sub.A /sin θ.sub.1 ' expression (2) where r A is an Airy radius of an incident beam spot and θ 1 ' is an incidence angle with respect to the surface of the optical waveguide.
Claim 5
Dependent Claim
14 words
A photocoupler according to claim 1, wherein the light incidence component is a prism.
Claim 6
Dependent Claim
15 words
A photocoupler according to claim 1, wherein the light incidence component is a dielectric plate.
Claim 7
Dependent Claim
19 words
A photocoupler according to claim 5, wherein the surface of the dielectric plate is provided with a non-reflective coating.
Claim 8
Dependent Claim
66 words
A method for producing a photocoupler of claim 1, comprising the steps of: applying a photoresist on a surface of the optical waveguide; forming a groove in the photoresist; injecting an adhesive into the groove; positioning and adjusting a light incidence component on the surface of the photoresist; bonding and fixing the light incidence component on the surface of the optical waveguide; and removing the photoresist.
Claim 9
Dependent Claim
67 words
A method for producing a photocoupler of claim 4, comprising the steps of: applying a photoresist on a surface of the optical waveguide; forming a groove in the photoresist; injecting an adhesive into the groove; positioning and adjusting the prism on the surface of the waveguide structure crossing over the groove; bonding and fixing the prism on the surface of the optical waveguide; and removing the photoresist.
Claim 10
Dependent Claim
43 words
A method for producing a photocoupler according to claim 7, wherein the thickness W of the photoresist is set to fulfill the relationship: w>h where, h is a height of the edge surface of the bonding section from the surface of the waveguide.
Claim 11
Dependent Claim
35 words
A method for producing a photocoupler according to claim 7, further comprising, after the step of forming a groove in the photoresist, a step of performing an RIE process on the surface of the waveguide.
Claim 12
Dependent Claim
33 words
A method for producing a photocoupler according to claim 7, wherein the step of bonding and fixing the light incidence component on the surface of the waveguide is performed using a photo-curable adhesive.
References Cited (Backward Citations)
US4637684A
Cited
US4932743A
Cited
US5208800A
Cited
JPH04289531A
Cited
US5235589A
Cited
JPH0545532A
Cited
US5199452A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-01-31 | 2003-08-02 | 2004-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-31 | 2007-08-02 | 2008-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-31 | 2011-08-02 | 2012-02-01 | $7700.00 | Window Closed / Lapsed |