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US 6,185,239 B2Granted
Semiconductor laser device
AssigneeSony Corporation
InventorsSeiji Ijuin, Shoji Hirata, Atsushi Ogasawara
Life of this patent
Estimating the term…
Abstract
A semiconductor laser device with reduced threshold current and power consumption. Reflectivity Rr at a rear face of an optical cavity of the laser is set as large as possible. A monitor photodiode used for controlling an output form the laser is provided on a mount at a position to detect the main laser beam emitted from the front face of the optical cavity.
Claims10
A semiconductor laser device, comprising:
- a semiconductor laser having a front end face from which a main laser beam is emitted and a rear end face from which a rear laser beam is emitted;
- a mount on which said semiconductor laser is disposed;
- a photodetector used for controlling an output from said semiconductor laser and also formed on said mount, wherein said photodetector is disposed to detect a main laser beam emitted from said front end, but said photodetector is not located in the path of said main beam
- wherein,
- assuming that a critical angle at which a main beam of said semiconductor laser is completely reflected by a tip end of said mount where said photodetector is disposed is θ, a numerical aperture of an optical system for collecting the main beam from said semiconductor laser is N.A. and refractive index of a surrounding medium is n, then said θ satisfies the relationship
- θ>α where (α=sin−1(N.A./n)).
3 more elements
A semiconductor laser device, comprising:
- a semiconductor laser having a front end face from which a main laser beam is emitted and a rear end face from which a rear laser beam is emitted;
- a mount on which said semiconductor laser is disposed;
- a photodetector used for controlling an output from said semiconductor laser and also formed on said mount, said photodetector disposed to detect a main laser beam emitted from said front end;
- and
- an electrode attached to said semiconductor laser between said semiconductor laser and said mount is located further from an active layer of said semiconductor laser than another electrode attached to the semiconductor laser.
2 more elements
A semiconductor laser device, comprising:
- a semiconductor laser having a front end face from which a main laser beam is emitted and a rear end face from which a rear laser beam is emitted;
- a mount on which said semiconductor laser is disposed;
- a photodetector used for controlling an output from said semiconductor laser and also formed on said mount, wherein said photodetector is disposed to detect a main laser beam emitted from said front end;
- an electrode attached to said semiconductor laser between said semiconductor laser and said mount is located further from an active layer of said semiconductor laser than another electrode attached to the semiconductor laser;
- and
- wherein,
- assuming that a critical angle at which a main beam of said semiconductor laser is completely reflected by a tip end of said mount where said photodetector is disposed is θ, a numerical aperture of an optical system for collecting the main beam from said semiconductor laser is N.A. and refractive index of a surrounding medium is n, then said θ satisfies the relationship
- θ>α where (α=sin−1(N.A./n)).
5 more elements
A semiconductor laser device comprising:
- a semiconductor laser having a front end face from which a main laser beam is emitted and a rear end face from which a rear laser beam is emitted;
- a mount on which said semiconductor laser is disposed;
- a photodetector used for controlling an output from said semiconductor laser and also formed on said mount, wherein said photodetector is disposed to detect a main laser beam emitted from said front end, but said photodetector is not located in the path of said main beam;
- and
- an electrode attached to said semiconductor laser but located further from an active layer of said semiconductor laser than another electrode attached to the semiconductor laser and secured onto said mount,
- wherein,
- a surface where said semidconductor laser is disposed is located at a position higher than a surface where said photodetector is disposed.
4 more elements
A semiconductor laser device comprising:
- a semiconductor laser having a front end face from which a main laser beam is emitted and a rear end face from which a rear laser beam is emitted;
- a mount on which said semiconductor laser is disposed;
- and
- a photodetector used for controlling an output from said semiconductor laser and also formed on said mount, wherein said photodetector is disposed to detect a main laser beam emitted from said front end, but said photodetector is not located in the path of said main beam,
- wherein,
- a surface where said semidconductor laser is disposed is located at a position higher than a surface where said photodetector is disposed, and
- assuming that a critical angle at which a main beam of said semiconductor laser is completely reflected by a tip end of said mount where said photodetector is disposed is θ, a numerical aperture of an optical system for collecting the main beam from said semiconductor laser is N.A. and refractive index of a surrounding medium is n, then said θ satisfies the relationship
- θ>α where (α=sin−1(N.A./n)).
5 more elements
Dependencies are inferred from the claim text.