SURFACE-EMITTING MICROLASERS FOR PHOTONIC SWITCHING AND INTERCHIP CONNECTIONS

Vertical-cavity electrically pumped surface-emitting microlasers are formed on GaAs substrates at densities greater than two million per square centimeter. Two wafers were grown with In0.2Ga$0.8$/As active material composing three 80 angstrom thick quantum wells in one and a single quantum well (SQW) 100 angstrom thick in the other. Lasing was seen in devices as small as 1.5 μm diameter with <0.05 μm3 active material. SQW microlasers 5 × 5 μm square had room-temperature cw current thresholds as low as 1.5 mA with 983 nm output wavelength. 10 × 10 μm square SQW microlasers were modulated by a pseudorandom bit generator at 1 Gb/s with less than 10-10 bit error rate. Pulsed output >170 mW was obtained from a 100 μm square device. The laser output passes through the nominally transparent substrate and out its back side, a configuration well suited for micro-optic integration and photonic switching and interchip connections.