Laser diode assembly with tunnel junctions and providing multiple beams

Abstract

A laser diode assembly provides multiple output beams from multiple p-n junctions in a multiplicity of stacked laser diodes with at least one tunnel junction. A semiconductor substrate has a multiplicity of superposed semiconductor laser stacks thereon each having an active layer sandwiched between p and n layers, and at least one pair of adjacent semiconductor laser stacks has a tunnel junction therebetween. When a potential is applied across the ohmic contacts on the outer surface of the substrate and the outer surface of the uppermost semiconductor laser stack, lasing is produced in the semiconductor stacks to form multiple beams. The tunnel junction may be provided by highly doped p.sup.+, n.sup.+ layers between the stacks, or it may be provided by highly doped abutting p.sup.+, n.sup.+ surface portions in the adjacent stacks. Tunnel junctions may be provided at the interfaces between all of the stacks, or between all but one pair of the adjacent stacks. The assembly may be edge emitting or surface emitting, and it may include single or multiple quantum well configurations and distributed feedback configuration.

Dependencies are inferred from the claim text.