Patent EP0044571A2 successfully refreshed from Google Patents.
EP0044571A2
Expired / Lapsed
EP
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Semiconductor laser device
Assignee: Hitachi Ltd
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Filing: 1981-07-23
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Granted: —
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Expires: 2001-07-23
Abstract
Abstract This invention consists in improvements in a buried-heterostructure laser with buried optical guide, and facilitates the oscillation of the laser in the fundamental mode thereof and also enhances the available percentage of production of the laser. An active layer (3) and an optical guide layer (2) are sandwiched between two cladding layers (1, 4), to form an optical confinement region. The width of the semiconductor material assembly varies in the stacking direction of the layers (1 ... 4), and the narrowest part (14) thereof is located on the side opposite to the optical guide layer (2) with reference to the position of the active layer (3). The side surface of said semiconductor material assembly parallel to the travelling direction of laser radiation is buried by a burying layer (6).
Inventors
- 👤 Shigeo Yamashita
- 👤 Hiroshi Matsuda
- 👤 Uichiro Kobayashi
- 👤 Masayoshi Kobayashi
- 👤 Hisao Nakashima
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 05:29
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; H01S5/22; H01S5/227; H01S5/2275
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
208 words
. In a semiconductor laser device wherein at least first, second, third and fourth semiconductor layers ( 1 ... 4) are stacked on a predetermined semiconductor body (10); the second semiconductor layer (2) has a lower refractive index than the third semiconductor layer (3); the first and fourth semiconductor layers (1, 4) have lower refractive indices than both the second and third semiconductor layers (2, 3) and conductivity types opposite to each other; the fourth and second semiconductor layers (4, 2) have greater band gaps than the third semiconductor layer (3); side surfaces of the first, second, third and fourth semiconductor (1 ... 4) layers parallel to a travelling direction of laser radiation are buried by a fifth semiconductor layer (56); the refractive index of the fifth semiconductor layer (5, 6) is at least lower than that of the third semiconductor layer (3), characterized in that a mesa-shaped semiconductor material assembly constructed of at least said first, second, third and fourth semiconductor layers (1 ... 4) has a width varying in the stacking direction of the layers, and that a narrowest part (14) of the mesa lies on a side opposite to said second semiconductor layer (2) with reference to the position of said third semiconductor layer (3).
Claim 2
Dependent Claim
208 words
. In a semiconductor laser device wherein at least first, second, third and fourth semiconductor layers ( 1 ... 4) are stacked on a predetermined semiconductor body (10); the second semiconductor layer (2) has a lower refractive index than the third semiconductor layer (3); the first and fourth semiconductor layers (1, 4) have lower refractive indices than both the second and third semiconductor layers (2, 3) and conductivity types opposite to each other; the fourth and second semiconductor layers (4, 2) have greater band gaps than the third semiconductor layer (3); side surfaces of the first, second, third and fourth semiconductor (1 ... 4) layers parallel to a travelling direction of laser radiation are buried by a fifth semiconductor layer (56); the refractive index of the fifth semiconductor layer (5, 6) is at least lower than that of the third semiconductor layer (3), characterized in that a mesa-shaped semiconductor material assembly constructed of at least said first, second, third and fourth semiconductor layers (1 ... 4) has a width varying in the stacking direction of the layers, and that a narrowest part (14) of the mesa lies on a side opposite to said second semiconductor layer (2) with reference to the position of said third semiconductor layer (3).
Claim 3
Dependent Claim
45 words
The semiconductor laser device of claim 1, charac- terized in that said fifth semiconductor layer consists of a plurality of layers (3, 6), in which at least one P-N junction is included, and said P-N junction is reverse-biased in operation of said semiconductor laser device.
Claim 4
Dependent Claim
26 words
The semiconductor laser device of claim 1 or 2, cha- racterized in that said fifth semiconductor layer (5, 6) is made of a high-resistivity semiconductor layer.
Claim 5
Dependent Claim
44 words
The semiconductor laser device of any of one of claims 1 to 3, characterized in that wherein said semiconductor body (10) and said first and second semiconductor layers (1, 2) have a n-conductivity type, and said fourth semiconductor layer (4) has a p-conductivity type.
References Cited (Backward Citations)
No citation records indexed.
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