SURFACE EMITTING LASER DIODE, OPTICAL SCANNING APPARATUS AND IMAGE FORMING APPARATUS
First Claim
1. A surface emitting laser diode comprising:
- a substrate;
a lower reflector formed over the substrate;
an active layer formed over the lower reflector;
an upper reflector formed over the active layer;
a current restrict structure including a current confinement region surrounded by insulation region, the current restrict structure is disposed in the upper reflector or between the active layer and the upper reflector; and
an upper electrode formed over the upper reflector includes an aperture which corresponds to an emission region from which light is emitted in a first direction perpendicular to a surface of the substrate, the emission region including a higher reflectance region having relatively higher reflectance and including a center of the emission region and a lower reflectance region having relatively lower reflectance;
whereina first current confinement region length of the current confinement region passing the center of the emission region and parallel to a second direction which is perpendicular to the first direction is equal to or smaller than a second current confinement region length of the current confinement region passing the center of the emission region in any other direction, and a third current confinement region length of the current confinement region in another of the any other direction is larger than the first current confinement region length,a first higher reflectance region length of the higher reflectance region passing the center of the emission region and parallel to the second direction is larger than a second higher reflectance region length of the higher reflectance region passing the center of the emission region and parallel to a third direction which is perpendicular to both the first direction and the second direction.
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Accused Products
Abstract
A surface emitting laser diode comprises a substrate, a lower reflector formed over the substrate, an active layer formed over the lower reflector, an upper reflector formed over the active layer, a current restrict structure including a current confinement region surrounded by insulation region. The current restrict structure is disposed in an upper reflector or between an active layer and the upper reflector, and an upper electrode formed over the upper reflector includes an aperture which corresponds to an emission region from which light is emitted in a first direction perpendicular to a surface of a substrate. The emission region and the current restrict structure including the current confinement region are selectively configured to obtain high single transverse mode, stabilized polarization direction, isotropic beam cross section and small divergence angle, while allowing the device to he manufactured with high yield rate.
12 Citations
12 Claims
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1. A surface emitting laser diode comprising:
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a substrate; a lower reflector formed over the substrate; an active layer formed over the lower reflector; an upper reflector formed over the active layer; a current restrict structure including a current confinement region surrounded by insulation region, the current restrict structure is disposed in the upper reflector or between the active layer and the upper reflector; and an upper electrode formed over the upper reflector includes an aperture which corresponds to an emission region from which light is emitted in a first direction perpendicular to a surface of the substrate, the emission region including a higher reflectance region having relatively higher reflectance and including a center of the emission region and a lower reflectance region having relatively lower reflectance; wherein a first current confinement region length of the current confinement region passing the center of the emission region and parallel to a second direction which is perpendicular to the first direction is equal to or smaller than a second current confinement region length of the current confinement region passing the center of the emission region in any other direction, and a third current confinement region length of the current confinement region in another of the any other direction is larger than the first current confinement region length, a first higher reflectance region length of the higher reflectance region passing the center of the emission region and parallel to the second direction is larger than a second higher reflectance region length of the higher reflectance region passing the center of the emission region and parallel to a third direction which is perpendicular to both the first direction and the second direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification