EP0765015A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Semiconductor laser device and optical disk drive
Assignee: Hitachi Ltd
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Filing: 1996-08-19
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Granted: —
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Expires: 2016-08-19
Abstract
Abstract An optical disk drive has an aberration detector (36, 40, 42) and an aberration correction circuit (47). A semiconductor laser device made of semiconductor crystals constituting a semiconductor laser light source (30) includes an active layer (3) for performing light amplification through current injection and guiding light in waveguide, a reflection member for reflecting light into said active layer, and a top electrode and a bottom electrode (11) used for current injection to the active layer, wherein the top electrode is divided into a main electrode (12) and a plurality of subsidiary electrodes (13, 14), and injection current to the subsidiary electrodes is controlled so as to correct an aberration generated at an optical focussing system (30, 31, 32, 33, 34) and an optical disk (35).
Inventors
- 👤 Katsuhiko Kimura
- 👤 Shozo Saegusa
- 👤 Masaru Muranishi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:51
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/0683; H01S5/30; G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/095; G11B7/0956; G11B7/12; G11B7/125; G11B7/127; H01S5/04; H01S5/042; H01S5/0425; H01S5/04254; H01S5/02; H01S5/0206; H01S5/0207; H01S5/022; H01S5/02208; H01S5/02212; H01S5/04256; H01S5/062; H01S5/06233; H01S5/06236; H01S5/0624; H01S5/06243; H01S5/06246; H01S5/0625; H01S5/06821; H01S5/10; H01S5/18; H01S5/183; H01S5/18305
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
103 words
A semiconductor laser device (15) made of semiconductor crystals having an active layer (3) for performing light amplification through current injection and guiding light in a waveguide, a reflection member for reflecting light into said active layer, and a top electrode and a bottom electrode (11) used for current injection to said active layer, wherein said top electrode is divided into a plurality of electrodes (12, 13, 14), and current is independently injected from each of the plurality of divided electrodes to said bottom electrode to emit laser radiation in the direction along the optical axis of the waveguide in said active layer.
Claim 2
Dependent Claim
47 words
A semiconductor laser device according to claim 1, wherein one of the plurality of divided electrodes of said semiconductor laser device is a main electrode (12), and the remaining electrodes are subsidiary electrodes (13, 14) divided along the optical axis of the waveguide in said active layer.
Claim 3
Dependent Claim
78 words
An optical disk drive having an optical disk (35), a semiconductor laser light source (30) for emitting a laser beam, an optical focussing system (31, 32, 33, 34) for focussing the laser beam from said semiconductor laser light source on said optical disk, and an optical detecting system (38) for detecting the laser beam reflected from said optical disk, characterized in that said semiconductor laser light source includes a semiconductor laser device according to claim 1 or 2.
Claim 4
Dependent Claim
91 words
An optical disk drive according to claim 3, wherein said top electrode of said semiconductor laser device includes a main electrode (12) and two subsidiary electrodes (13, 14) divided along the optical axis of the waveguide in said active layer; and one of the two subsidiary electrodes is connected via a resistor to a first current supply path (150) and the other is connected via a resistor to a second current supply path (151), and said main electrode is connected via respective resistors to said first and second current supply paths.
Claim 5
Dependent Claim
31 words
An optical disk drive according to claim 3 or 4, wherein a total of injection currents supplied to said subsidiary electrodes is smaller than injection current supplied to said main electrode.
Claim 6
Dependent Claim
61 words
An optical disk drive according to one of claims 3 to 5, wherein said semiconductor laser light source accommodates said semiconductor laser device in a hermetically sealed package, and includes a lead (21) connected to said main electrode, a plurality of leads (22, 23) respectively connected to the plurality of subsidiary electrodes, and a lead (26) connected to said bottom electrode.
Claim 7
Dependent Claim
94 words
An optical disk drive according to one of claims 3 to 6, wherein said semicondcutor laser light source accommodates said semiconductor laser device and a photodetector (24) for detecting light emitted from said semiconductor laser device, in a hermetically sealed package, and includes a lead (21) connected to said main electrode, a plurality of leads (22, 23) respectively connected to the plurality of subsidiary electrodes, a lead (25) connected to one electrode of said phtodetector, and a lead (26) connected in common to the other electrode of said photodetector and to said bottom electrode.
Claim 8
Dependent Claim
93 words
An optical disk drive according to one of claims 3 to 6, wherein said semiconductor laser light source accommodates said semiconductor laser device and a photodetector for detecting light emitted from said semiconductor laser device, in a hermetically sealed package, and includes a lead (21) connected to said main electrode, a plurality of leads (22, 23) respectively connected to the plurality of subsidiary electrodes, a lead (25) connected to one electrode of said photodetector, a lead connected to the other electrode of said photodetector, and a lead (26) connected to said bottom electrode.
Claim 9
Dependent Claim
71 words
An optical disk drive according to one of claims 3 to 8, further comprising: aberration detecting (36, 40, 42) means for detecting an aberration generated at said optical focussing system and said optical disk; and correction means (47) for correcting said aberration by controlling injection current to said semiconductor laser device and changing the shape of a laser radiation wave front in accordance with an output of said aberration detecting means.
Claim 10
Dependent Claim
90 words
An optical disk drive according to one of claims 3 to 9, further comprising inclination detecting means (60, 61, 62) for detecting a shift of an angle between a recording surface of said optical disk and the optical axis of a laser beam applied from said optical focussing system to said optical disk; and correction means (66) for correcting said angle shift by controlling injection current to said semiconductor laser device and changing the optical axis of the laser beam in accordance with an output of said inclination detecting means.
References Cited (Backward Citations)
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