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-mu m-thick bulk GaAs active region. The transverse far field is independent of the aperture size for diameters less than or equal to 3 mu m, although threshold reduction occurs with reducing aperture size down to similar to 0.5 mu m 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. (C) 1997 American Institute of Physics.