US Patent 7795609 Densely stacked and strain-compensated quantum dot active regions

Embodiments provide a quantum dot active structure and a methodology for its fabrication. The quantum dot active structure includes a substrate, a plurality of alternating regions of a quantum dot active region and a strain-compensation region, and a cap layer. The strain-compensation region is formed to eliminate the compressive strain of an adjacent quantum dot active region, thus allowing quantum dot active regions to be densely-stacked. The densely-stacked quantum dot active region provides increased optical modal gain for semiconductor light emitting devices such as edge emitting lasers, vertical cavity lasers, detectors, micro-cavity emitters, optical amplifiers or modulators.