Crenelated-ridge waveguide laser
AssigneeBell Telephone Laboratories, Incorporated
InventorIvan P. Kaminow
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Abstract
The ridge-structure in a ridge waveguide laser is notched at periodic intervals to produce a longitudinally crenelated ridge, and the electrode on the ridge side of the laser is alloyed only to the topmost surfaces of the ridge. As a result, the active region of the laser is pumped only in the regions that are underneath the topmost surfaces of the ridge, and the laser is caused to prefer the longitudinal modes whose maxima coincide with the spatial Fourier components of the pumped regions.
Claims8
In a ridge-type semiconductor laser comprising a substrate having a plurality of epitaxially grown layers one of which includes an active layer containing a pn-junction, a ridge structure epitaxially grown and fabricated on said plurality of epitaxial layers, and means for providing current to said pn-junction in said active layer, said current being confined in a lateral dimension by said ridge structure, characterized in that said ridge structure is notched in regions at longitudinal periodic intervals, and said means for providing current couples said current into said active layer only in regions corresponding to the portions of said ridge that are not notched.
In a semiconductor laser comprising a substrate of one type conductivity having an epitaxially grown layer of the same conductivity on one surface and an electrode on an opposite surface, an active layer epitaxially grown with a pn-junction on said layer of said substrate, a buffer layer of opposite conductivity epitaxially grown on said active layer, a ridge of opposite conductivity epitaxially grown on said buffer layer and extending along the length of said semiconductor laser, and a second electrode alloyed to the top of said ridge, characterized in that said ridge is notched substantially to the level of said buffer layer at periodic intervals along the length of said laser.
Dependencies are inferred from the claim text.