US4772784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor laser apparatus for optical head
Assignee: Sony Corp
•
Filing: 1987-04-22
•
Granted: 1988-09-20
•
Expires: 2007-04-22
Abstract
Abstract A semiconductor laser apparatus having a semiconductor laser diode for radiating a laser beam, a photodetector formed on a semiconductor substrate, a prism having a first plane for introducing the laser beam to a reflecting substance and introducing the beam reflected by the reflecting substance to the photodetector and a second plane facing to the photodetector, and a coating layer formed on the boundary between the semiconductor substrate and the prism, having a refractive index such that the laser beam incident from the first plane other than the laser beam reflected by the reflecting substance is inhibited from reaching the photodetector.
Inventors
- 👤 You Yoshitoshi
- 👤 Yoshiyuki Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:57
CPC Classifications
G; G02; G02B; G02B1/00; G02B1/10; G11; G11B; G11B7/00; G11B7/12; G11B7/123; G11B7/135; G11B7/1359; G11B7/1381; H; H01; H01S; H01S5/00; H01S5/02; H01S5/022; H01S5/0225; H01S5/02255; H01S5/023; H01S5/02325; H01S5/06; H01S5/068; H01S5/0683
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
104 words
A semiconductor laser apparatus comprising: a semiconductor substrate; a semiconductor laser diode for radiating a laser beam; a photodetector formed on said semiconductor substrate; a prism having a first plane for introducing said laser beam to a reflecting substance and introducing a laser beam reflected by said reflecting substance to said photodetector and a second plane facing to said photodetector; and a coating means formed on a boundary between said semiconductor substrate and said prism, having a refractive index such that laser beam incident from said first plane other than said laser beam reflected by said reflecting substance is inhibited from reaching said photodetector.
Claim 2
Dependent Claim
104 words
A semiconductor laser apparatus comprising: a semiconductor substrate; a semiconductor laser diode for radiating a laser beam; a photodetector formed on said semiconductor substrate; a prism having a first plane for introducing said laser beam to a reflecting substance and introducing a laser beam reflected by said reflecting substance to said photodetector and a second plane facing to said photodetector; and a coating means formed on a boundary between said semiconductor substrate and said prism, having a refractive index such that laser beam incident from said first plane other than said laser beam reflected by said reflecting substance is inhibited from reaching said photodetector.
Claim 3
Dependent Claim
31 words
A semiconductor laser apparatus as claimed in claim 1, wherein said coating means is formed of a plurality of layers, each of which has a different refractive index from each other.
Claim 4
Dependent Claim
38 words
A semiconductor laser apparatus as claimed in claim 2, wherein said plurality of layers consists of two layers, a first layer is made of SiO 2 and a second layer is made of Si 3 N 4 .
Claim 5
Dependent Claim
25 words
A semiconductor laser apparatus as claimed in claim 3, wherein said first layer is thicker than said second layer and formed on said semiconductor substrate.
Claim 6
Dependent Claim
25 words
A semiconductor laser apparatus as claimed in claim 1, wherein said first plane and said second plane of said prism respectively comprise a half mirror.
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) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |