Patent ID: 6905900

Claim:
A method of producing a single mode VCSEL comprising the steps of: forming a VCSEL structure having a substrate, a bottom contact portion disposed below a lower surface of the substrate, a lower mirror portion disposed above an upper surface of the substrate, an active region disposed above the lower mirror portion, and an upper mirror portion disposed above the active region formed from an electrically isotropic material, the upper mirror portion having layers of a first mobility material and layers of a second mobility material, the first mobility being higher than the second mobility, wherein the layers of the first mobility material are doped less than the layers of the second mobility material except at graded interfaces between the first mobility material and the second mobility material when a doping level at the interfaces is graded so that the resistivity of the upper mirror portion is substantially independent of direction; providing a substantially equipotential layer disposed above the upper mirror portion; providing an electrically insulating layer between the upper mirror portion and the equipotential layer to form an aperture therebetween; and providing an upper contact portion disposed above the equipotential layer.