1.55-μm vertical-cavity surface-emitting lasers with directly grown AlGaAs/GaAs and AlxOy /GaAs DBR mirrors

It is possible to grow defect-free strained layers on patterned substrates (mesas or grooves) up to thicknesses far exceeding the critical thickness. Defect nucleation and propagation are inhibited in such growth. We have exploited this property to design and fabricate InP-based 1.55 micrometers vertical cavity surface emitting lasers. Careful photoluminescence and TEM studies have confirmed that there are no propagating defects in the GaAs/AlxGa1-xAs DBR grown on the patterned active region, or the MQW region. Lasers have been made with InP/InGaAsP bottom mirrors, laterally oxidized InAlAs current confining layers and GaAs/AlxOy top DBR mirrors. Lasers with 8 - 40 micrometers diameter have been characterized. A threshold current of 5 mA is observed at 15 degree(s)C for a 8 micrometers diameter device; and up to 60 (mu) W of light output is recorded.