TY - JOUR T1 - Improved performance from GaAs–AlGaAs quantum cascade lasers with enhanced upper laser level confinement JO - Physica E: Low-dimensional Systems and Nanostructures PY - 2000/04/01 AU - Keightley PT AU - Wilson LR AU - Cockburn JW AU - Skolnick MS AU - Clark JC AU - Grey R AU - Hill G AU - Hopkinson M ED - DO - DOI: 10.1016/s1386-9477(99)00279-9 PB - Elsevier BV VL - 7 IS - 1-2 SP - 8 EP - 11 Y2 - 2024/12/22 ER -