Single-mode operation of mushroom structure surface emitting lasers

Mushroom structure vertical cavity surface emitting lasers with a 0.6- mu m GaAs active layer sandwiched by two Al/sub 0.6/Ga/sub 0.4/As-Al/sub 0.08/Ga/sub 0.92/As multilayers as top and bottom mirrors are discussed. The lasers exhibit a 15-mA pulses threshold current at 880 nm. Single longitudinal and single transverse mode operation was achieved on lasers with a 5- mu m-diameter active region of current levels near 2*l/sub th/. The light output above threshold current was linearly polarized with a polarization ratio of 25:1.<
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