Comparison of performance of GaAs-AlGaAs and InGaAs-AlInAs quantum cascade lasers

摘要

The authors present the lasing characteristics of a dry etched GaAs-AlGaAs quantum cascade laser (/spl lambda/=9.5 /spl mu/m) and compare its temperature performance with that of a similar InGaAs-AlGas laser (/spl lambda/=8.3 /spl mu/m). In pulsed operation, the maximum peak power measured for the GaAs-AlGaAs device is 400 mW at 10K and lasing is observed up to 190 K. The threshold current density (J/sub th/) measured for this sample increases rapidly above 120 K, in contrast to the InGaAs-AlInAs laser, which exhibits a gradual increase of J/sub th/ up to 270 K. Temperature-dependent studies of a slightly modified GaAs-AlGaAs laser, in which the confinement of the upper laser level is increased, indicate that this aspect of the design does not limit the high temperature performance.