Patterning of diode/substrate interface to reduce thermal lensing

A laser diode array comprising:

• a semiconductor multilayer comprising a plurality of emission regions arranged in a linear array, consecutive emission regions separated from each other by non-emitting regions of said semiconductor multilayer;
• a metal layer;
• a substrate disposed with respect to said semiconductor multilayer such that said metal layer is between said semiconductor multilayer and said substrate, said substrate providing a heat sink for at least portions said semiconductor multilayer;
• and
• a plurality of gaps between said semiconductor multilayer and said substrate, said gaps disposed between contact regions, respective ones of said contact regions forming electrical contact with respective ones of said emission regions of said semiconductor multilayer, respective ones of said contact regions forming thermally conductive pathways with respective ones of said emission regions, individual ones of said thermally conductive pathways having said gaps on opposite sides thereof,
• wherein said semiconductor multilayer has top and bottom surfaces, said bottom surface closer to said substrate than said top surface, wherein said bottom surface of the semiconductor multilayer is flat across a width extending across a plurality of emission and non-emitting regions.