US3894789A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light beam coupler for semiconductor lasers
Assignee: NEC Corp
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Filing: 1974-07-29
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Granted: 1975-07-15
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Expires: 1994-07-29
Abstract
Abstract A light coupler is disclosed for use in transforming a flat cross-sectional output beam of a laser into a light beam having a substantially circular cross-section of a spot size for efficient coupling to an optical fiber. The light coupler includes first and second light transmission bodies disposed in an optically coaxial cascade relationship. The first and second light transmission bodies satisfy the conditions ax > ay (where ay can be zero) and ax < OR = ay (where ax can be zero), respectively, the symbols ax and a y being the focusing parameters representing the values of change in the refractive index distribution in the x- and y-directions parallel to the thickness and width directions in the cross-section of the laser beam incident upon the light transmission bodies, in a plane normal to the optical axes of the light transmission bodies.
Inventors
- 👤 Kohroh Kobayashi
- 👤 Atsufumi Ueki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:10
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4202; G02B6/4203; G02B6/4204; G02B6/4206; H; H01; H01S; H01S5/00; H01S5/02; H01S5/026; H01S3/00; H01S3/005; H01S5/005
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
176 words
A light beam coupler for use in transforming an output beam with a flat cross-section into a light beam with a substantially circular cross-section; said light beam coupler comprising a first light transmission body disposed in the vicinity of a semiconductor laser, and a second light transmission body disposed in an optically coaxial cascade relationship with said first light transmission body wherein, in the plane of crosssection perpendicular to the optical axes of said first and second light transmission bodies, the refractive index distribution decreases substantially proportionally to the square of the distance from said optical axis in at least one direction, and the gradients ax and ay for said refractive index distribution meet the condition ax > ay (where ay can be zero) in said first light transmission body, and the condition ax < OR = ay (where ax can be zero) in said second light transmission body, the gradient ax being taken in the direction perpendicular to the p-n junction plane of the semiconductor laser, and the gradient ay in the direction parallel thereto.
Claim 2
Dependent Claim
176 words
A light beam coupler for use in transforming an output beam with a flat cross-section into a light beam with a substantially circular cross-section; said light beam coupler comprising a first light transmission body disposed in the vicinity of a semiconductor laser, and a second light transmission body disposed in an optically coaxial cascade relationship with said first light transmission body wherein, in the plane of crosssection perpendicular to the optical axes of said first and second light transmission bodies, the refractive index distribution decreases substantially proportionally to the square of the distance from said optical axis in at least one direction, and the gradients ax and ay for said refractive index distribution meet the condition ax > ay (where ay can be zero) in said first light transmission body, and the condition ax < OR = ay (where ax can be zero) in said second light transmission body, the gradient ax being taken in the direction perpendicular to the p-n junction plane of the semiconductor laser, and the gradient ay in the direction parallel thereto.
Claim 3
Dependent Claim
70 words
The light beam coupler of claim 1, in which said first light transmission body comprises means for transforming the flat cross-sectional output beam of the laser to an intermediate beam having an substantially circular cross-section of a first diameter, and said second light transmission body comprises means for transforming said intermediate beam to an output beam having a substantially circular cross-section of a second diameter less than said first diameter.
Claim 4
Dependent Claim
64 words
The light coupler of claim 1, in which said first light transmission body comprises means for transforming the flat cross-sectional laser output beam to an intermediate beam having a substantially elliptical cross-section, and said second light transmission body comprises means for transforming said beam to an output bEam having a substantially circular cross-section beam of a reduced size, as compared to said intermediate beam.
Claim 5
Dependent Claim
28 words
The light coupler of claim 1, in which said first light transmission body is rectangular in cross-section, and said second light transmission body is substantially circular in cross-section.
Claim 6
Dependent Claim
74 words
The light coupler of claim 1, in which said first and second light transmission bodies are rectangular in cross-section, the major dimension of said first light transmission body extending in a direction parallel to the major dimension of the flat cross-sectional laser beam, and the major dimension of said second light transmission body extends in a direction perpendicular thereto and in a direction parallel to the major axis of said elliptical cross-sectional elliptical beam.
Claim 7
Dependent Claim
49 words
The light coupler of claim 1, further comprising means for mounting and spacing said first and second light transmission bodies from one another, and for aligning the optical axes of said first and second light transmission bodies with one another and with the output beam of the semiconductor laser.
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) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |