Patent EP0461632A2 successfully refreshed from Google Patents.
EP0461632A2
Expired / Lapsed
EP
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Phase-shifted distributed feedback type semiconductor laser device
Assignee: Toshiba Corp
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Filing: 1991-06-12
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Granted: —
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Expires: 2011-06-12
Abstract
Abstract A semiconductor laser device has a periodic structure for distributively feeding back light. A waveguide (18) for guiding light along the periodic structure is provided. A plurality of waveguide regions (4, 5) having a light confinement coefficient set to vary along the periodic structure and an equivalent amount of phase shift with respect to the phase of the periodic structure set to an integer multiple of π are provided. The total phase shifting amount of light by the waveguide (18) is set to a value different from an integer multiple of π.
Inventors
- 👤 Takayuki C/O Intellectual Pty Division Matsuyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 04:19
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/12; H01S5/30; H01S5/32; H01S5/1053; H01S5/1064; H01S5/124; H01S5/1243; H01S5/20; H01S5/22; H01S5/227; H01S5/2275
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
99 words
A semiconductor laser device comprising a periodic structure (2) for distributively and feeding back light, said periodic structure (2) forming a laser cavity; and a waveguide (18, 18') for guiding the light along said periodic structure (2), said waveguide (18, 18') having a light confinement coefficient changing along an axis of said laser cavity, characterized in that the sum of the total phase shift of light, which occurs in said waveguide (18, 18'), and an equivalent phase shift of light, which occurs due to the phase of the periodic structure (2), is other than an integral multiple of π.
Claim 2
Dependent Claim
28 words
A semiconductor laser device according to claim 1, characterized in that the sum of the phase shift of light is nπ/2, where n is a positive odd number.
Claim 3
Dependent Claim
25 words
A semiconductor laser device according to claim 1, characterized in that the middle portion of said laser cavity is broader than either end portion thereof.
Claim 4
Dependent Claim
27 words
A semiconductor laser device according to claim 1, characterized in that said waveguide (18') has a plurality of wave-guiding regions having different propagation constants (β₁, β₂, β₃).
Claim 5
Dependent Claim
40 words
A semiconductor laser device according to claim 1, characterized in that the phase shifting amount of light, which occurs in said waveguide (18, 18'), is set by changing the thickness of the waveguide along the axis of the laser cavity.
Claim 6
Dependent Claim
65 words
A semiconductor laser device according to claim 1, characterized in that the total phase shift of light, which occurs in said waveguide (18), is an integral multiple of π, and the sum of the equivalent phase shift of light, which occurs due to the phase of the periodic structure (2) and the total phase shift of light is other than an intergral multiple of π.
Claim 7
Dependent Claim
65 words
A semiconductor laser device according to claim 1, characterized in that the total phase shift of light, which occurs in said waveguide (18'), is other than an intergral multiple of π, and the sum of the equivalent phase shift of light, which occurs due to the phase of the periodic structure (2) and the total phase shift of light is an integral multiple of π.
References Cited (Backward Citations)
No citation records indexed.
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