DESIGN AND SIMULATION OF LOW-THRESHOLD ANTIMONIDE INTERSUBBAND LASERS

Optically and electrically pumped infrared lasers based on intersubban d transitions in InAs/GaSb/AlsSb quantum wells are modeled in detail. The large conduction-band offset of the AlAsSb barriers with respect t o the InAs wells allows the lasing wavelength to be shortened to at le ast 1.9 mu m. Furthermore, the small InAs electron mass results in lon ger phonon-limited lifetimes in the upper lasing subband as well as la rger dipole matrix elements. This leads to the prediction of lower thr eshold currents, and hence, higher cw operating temperatures than for quantum cascade lasers based on the InCaAs/InAlAs/InP system. (C) 1998 American Institute of Physics.