High-efficiency AlGaInP/AlGaAs vertical-cavity surface-emitting lasers with 650 nm wavelength

The optimisation of red, AlGaInP/AlGaAs-based, selectively oxidised vertical-cavity surface-emitting lasers (VCSELs) with 650 nm emission wavelength having all-semiconductor p-distributed Bragg reflectors is reported. The increase of the AlP content in parts of the cavity, tailoring of the doping profile and removal of the contact layer in the output window lead to VCSELs with threshold current densities of 1.8 kA/cm² and continuous wave output powers of 3.1 mW to 4.6 mW at 20°C for wavelengths between 650 nm and 657 nm. These devices with current apertures around 13 μm show laser emission above temperatures of 40°C; devices with smaller apertures and room temperature output powers of 1 mW show laser emission up to 60°C.