Very small oxide-confined vertical-cavity surface-emitting lasers with a bulk active region

Data are presented characterizing very small oxide aperture vertical-cavity surface-emitting lasers with a 0.5-μm-thick bulk GaAs active region. The transverse far field is independent of the aperture size for diameters ⩽3 μm, although threshold reduction occurs with reducing aperture size down to ∼0.5 μm diam. Threshold reduction is attributed to improved overlap between the optical mode and gain profile. The large signal temporal response is characterized using optical gain switching.