Improved temperature performance of Al0.33Ga0.67As/GaAs quantum-cascade lasers with emission wavelength at lambda approximate to 11 mu m

The pulsed operation of a GaAs/AlGaAs quantum-cascade laser is reported up tc, 258 K. These devices emit at 11.3 mu m and are based on a plasmon-confi nement waveguide. To optimize the material gain, the active region is desig ned to diminish electron escape to continuum states. Gain and threshold mea surement show evidence of better carrier confinement and improved thermal b ehavior compared to lambda approximate to 9 mu m GaAs quantum-cascade laser s. The maximum peak-collected power at 77 K is 520 mW per facet and still 2 7 mW at 258 K. The temperature dependence of the threshold current density is characterized by a T-0 = 128 K. (C) 2000 American Institute of Physics. [S0003-6951(00)00623-9].