Article comprising a semiconductor laser that is non-degenerate with regard to polarization
AssigneeAT&T Corp.
InventorDaryoosh Vakhshoori
Life of this patent
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Abstract
The output of vertical cavity surface emitting layers (VC-SELs) generally lacks polarization stability due to polarization mode degeneracity. I have discovered that in the usual (001) laser geometry polarization mode degeneracity can be removed if the active region of the laser is selected such that the active region lacks mirror symmetry with respect to any plane normal to the [001] crystal direction. Exemplarily, the active region comprises one or more asymmetrical quantum wells, e.g., quantum wells having a saw-tooth profile. The invention can also be embodied in edge emitting lasers, but embodiment in VC-SELs is preferred.
Claims6
An article comprising a semiconductor laser comprising a multilayer epitaxial semiconductor structure comprising III-V semiconductor material, associated with said structure being a direction normal to the structure and a crystal orientation such that the crystal direction is substantially parallel to said direction normal to the structure, the structure comprising an active region between first and second cladding regions, the article further comprising contact means that facilitate flowing charge carriers into said active region.
- CHARACTERIZED IN THAT
- said active region has a composition selected such that the active region does not have mirror symmetry with respect to any plane that is normal to said [001] crystal direction.
Dependencies are inferred from the claim text.