Optical loss and lasing characteristics of high-quality-factor AlGaAs microdisk resonators with embedded quantum dots

Optical characterization of AlGaAs microdisk resonant cavities with a quantum dot active region is presented. Direct passive measurement of the optical loss within AlGaAs microdisk resonant structures embedded with InAs/ InGaAs dots-in-a-well sDWELLd is performed using an optical-fiber-based probing technique at a wavelength sl,1.4 mmd that is red detuned from the dot emission wavelength sl,1.2 mmd. Measurements in the 1.4 mm wavelength band on microdisks of diameter D=4.5 mm show that these structures support modes with cold-cavity quality factors as high as 3.63105. DWELL-containing microdisks are then studied through optical pumping at room temperature. Pulsed lasing at l,1.2 mm is seen for cavities containing a single layer of InAs dots, with threshold values of ,17 mW, approaching the estimated material transparency level. Room-temperature continuous-wave operation is also observed. © 2005 American Institute of Physics. fDOI: 10.1063/1.1901810g