Optical device with composite passive and tapered active waveguide regions
AssigneeBritish Telecommunications public limited company
InventorsIan F. Lealman, Michael J. Robertson, Simon D. Perrin
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Abstract
A semiconductor optical device, for example a laser, has a composite optical waveguide including a tapered, MQW active waveguide in optical contact with a substantially planar, passive waveguide. The fundamental optical mode supported by the composite waveguide varies along the length of the composite waveguide so that, in a laser, the laser mode is enlarged and is a better match to single mode optical fiber. A method for making such semiconductor optical devices is also disclosed.
Claims20
A semiconductor optical device including a composite optical waveguide having a length dimension with first and second ends, the composite waveguide comprising:
- a first optically waveguiding region of semiconductor material, which first region is optically passive and is substantially planar, and
- a second optically waveguiding region, of semiconductor material, which second region includes an optically active multi-quantum well structure tapered along a substantial part of its length in a direction substantially parallel to the plane of the first region,
- the first and second regions being in optical contact and the size of the fundamental optical mode supported by the composite waveguide varying along the length of the composite waveguide;
- and
- the first region being of substantially constant width along the length of the composite waveguide.
Dependencies are inferred from the claim text.