1.55-μm buried-heterostructure VCSELs with InGaAsP/lnP-GaAs/AlAsDBRs on a GaAs substrate

We demonstrate 1.55-μm buried-heterostructure (BH) vertical-cavity surface-emitting lasers (VCSELs) on a GaAs substrate. Thin-film wafer-fusion technology enables InP-based BH VCSELs to be fabricated on GaAs/AlAs distributed Bragg reflectors. Detailed investigations of the device resistance are also described. As a result of introducing BH and obtaining low device resistance, the threshold current density under CW operation shows the independence of mesa size due to a strong index guide and small noneffective current. A 5-μm VCSEL exhibits a record threshold current of 380 μA at 20°C. This VCSEL also operates with single transverse mode up to the maximum optical output power