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Vertically-stacked multiple quantum wire semiconductor lasers

We report the structure and lasing characteristics of GaAs/AlGaAs vertically stacked multiple‐quantum‐wire (QWR) semiconductor lasers grown by organometallic chemical vapor deposition on V‐grooved substrates. The active region in these lasers consists of three crescent‐shaped wires, placed at the center of a single‐mode optical waveguide. The higher optical confinement factor, compared to single‐QWR structures, leads to reduced threshold currents, as low as 0.6 mA for high‐reflection coated devices at room temperature. The lower threshold carrier density results in oscillation at a lower QWR subband as compared to single‐QWR laser structures.