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Patent EP0348941A2 successfully refreshed from Google Patents.
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EP0348941A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Semiconductor laser device

Assignee: NEC Corp
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Filing: 1989-06-28
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Granted: —
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Expires: 2009-06-28
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Abstract

Abstract A semiconductor laser device comprises an active layer (10) of a refractive index n₁, first and second inner cladding layers (20, 30) of a refractive index n₂ and a bandgap energy greater than that of the active layer (10) provided on the both sides of the active layer to form a double heterostructure, and first and second outer cladding layers (40, 50) of a refractive index n₃ provided on the both sides of the double heterostructure. The refractive indices n₁, n₂ and n₃ meet a relation of "n₁ > n₃ > n₂", so that a vertical radiation angle of an output light beam is controlled in accordance with a thickness of the first and second inner cladding layers, and the refractive index n₃, even if the active layer is thick.

Inventors

  • 👤 Kenichi Kobayashi

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-07 02:05
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; H01S5/22; H01S5/223; H01S5/2231; H01S5/2004

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 131 words
A semiconductor laser device, comprising: a double heterostructure including an active layer and first and second inner cladding layers provided on both sides of said active layer, said double heterostructure being provided on a semiconductor substate and a bandgap energy of said first and second inner cladding layers being greater than that of said active layer; first and second outer cladding layers provided on both sides of said double heterostructure; and first and second electrodes for applying a predetermined voltage across said double heterostructure; wherein a refractive index of said active layer is greater than refractive index of said first and second outer cladding layers, and said refractive index of said first and second outer cladding layers is greater than a refractive index of said first and second inner cladding layers.
Claim 2
Dependent Claim 131 words
A semiconductor laser device, comprising: a double heterostructure including an active layer and first and second inner cladding layers provided on both sides of said active layer, said double heterostructure being provided on a semiconductor substate and a bandgap energy of said first and second inner cladding layers being greater than that of said active layer; first and second outer cladding layers provided on both sides of said double heterostructure; and first and second electrodes for applying a predetermined voltage across said double heterostructure; wherein a refractive index of said active layer is greater than refractive index of said first and second outer cladding layers, and said refractive index of said first and second outer cladding layers is greater than a refractive index of said first and second inner cladding layers.
Claim 3
Dependent Claim 50 words
A semiconductor laser device, according to claim 1 wherein: said first and second inner cladding layers are of a thickness dependent on a vertical radiation angle of an output light beam, and said first and second outer cladding layers are of a refractive index dependent on said vertical radiation angle.

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