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US 5,497,391 AGranted
Monolithic array of independently addressable diode lasers
AssigneeXerox Corporation
InventorThomas L. Paoli
Life of this patent
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Abstract
A monolithic array of two or more independently addressable, closely spaced diode lasers having low thermal, electrical, and optical crosstalk. An isolation region is formed between the adjacent laser elements, which are defined by rib loaded waveguides created by etching mesas above a planar active multilayer waveguide. Separate electrical connections to the ribs, and a common electrical connection to the substrate, enable individual addressing of each laser element. Selectively added blocking layers and/or insulating layers are added to the structure to provide improved electrical and/or thermal isolation.
Claims16
A monolithic semiconductor light emitting array, comprising:
- a doped semiconductor substrate having a defined conductivity type, and having first and second surfaces;
- a multilayer structure on said first surface of said doped semiconductor substrate, said multilayer structure including a first semiconductor confinement layer having a same conductivity type as said doped semiconductor substrate, a second semiconductor confinement layer having an opposing conductivity type than the conductivity type of said doped semiconductor substrate, and an etch stop layer, said multilayer structure further including an active semiconductor layer for generating light, said active layer being intervenient to said first and second semiconductor confinement layers and having a smaller bandgap than said first and second confinement layers;
- a plurality of mesas, wherein each individual one of said plurality of mesas is disposed adjacent a first side of said etch stop layer;
- a plurality of addressing electrodes, wherein each of said addressing electrodes is adjacent and in electrical communication with an associated individual one of said mesas;
- an isolation region between two of said mesas, wherein said isolation region extends from the opposite side of said first side of said etch stop layer, and continues to extend through said second confinement layer, said active layer, and at least into said first confinement layer;
- and
- a common electrode on said second surface of said substrate, said common electrode for cooperating with each of said addressing electrodes to enable current flow through the mesa associated with each of said addressing electrodes.
4 more elements
A monolithic laser array, comprising:
- a semiconductor substrate having a defined conductivity type and having first and second surfaces;
- a multilayer structure on said first surface of said substrate, said multilayer structure including at least a first semiconductor confinement layer having a same conductivity type as said substrate, a second semiconductor confinement layer having the opposing conductivity type to said substrate, and an etch stop layer, said multilayer structure further including an active semiconductor layer for generating and propagating laser light, said active layer being intervenient to said first and second semiconductor confinement layers and having a smaller bandgap than said first and second confinement layers;
- a plurality of mesas, wherein each one of said plurality of mesas is disposed adjacent a first side of said etch stop layer, said mesas for laterally forming the lasing optical field;
- a plurality of addressing electrodes, wherein each of said addressing electrodes is adjacent and in electrical communication with an associated one of said mesas;
- an isolation region between two of said mesas, wherein said isolation region extends from the opposite side of said first side of said etch stop layer, and continues to extend through said second confinement layer, said active layer, and at least into said first confinement layer;
- and
- a common electrode on said second surface of said substrate, said common electrode for cooperating with each of said addressing electrodes to enable current flow through the mesa associated with each of said addressing electrodes.
4 more elements
Dependencies are inferred from the claim text.