Semiconductor surface emitting laser having reduced threshold voltage and enhanced optical output
AssigneeAT&T Bell Laboratories
InventorKent D. Choquette
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Abstract
The present applicant has discovered that one can make a surface emitting laser with enhanced operating characteristics by etching away the outer reflector stack peripheral to the intended active area and protecting the reflector stack mesa remaining over the active area by in situ metalization in high vacuum. The active area can be isolated, as by ion implantation, providing an electrical path through the active region free of the outer reflector stack. The result is a surface emitting laser having reduced series resistance. The device lases at lower voltage and provides an enhanced intensity of optical output as compared with conventional planar devices.
Claims5
In a vertical cavity, surface emitting laser of the type comprising a semiconductor active region disposed between a pair of Bragg reflector stacks each comprising a plurality of longitudinally extending reflector layers and a pair of metal contact layers for providing a current through said active region, the improvement wherein at least one of said reflector stacks terminates in at least one substantially transverse wall peripheral to said active region and one of said metal contact layers substantially covers said wall.
Dependencies are inferred from the claim text.