GaAs/AlGaAs-based microcylinder lasers emitting at 10 mu m

The realization of electrically pumped GaAs/AlGaAs quantum cascade microcyl inder lasers is reported. Design and fabrication of special resonator shape s (microcylinder and ridge waveguide) are presented. Threshold characterist ics and optical output of different resonators of the same quantum cascade laser material emitting at 10 mu m are investigated. A low threshold curren t of 318 mA is obtained for a microcylinder resonator with circular cross s ection. The maximum working temperature of the microcylinder lasers is 165 K. Single mode emission is detected with a side mode suppression ratio bett er than 20 dB. (C) 1999 American Institute of Physics. [S0003-6951(99)04334 -X].