GaSb-Based Interband Cascade Lasers With Hybrid Claddings Operating at High Temperatures

We report the first demonstration of continuous-wave (CW) operation to well above room temperature for GaSb-based interband cascade lasers (ICLs) with hybrid claddings. The optical claddings of the ICLs consisted of n-SL intermediate claddings, followed by n+-InAs0.91Sb0.09 outer claddings. Such a cladding design is potentially advantageous over the conventional SL cladding, since it enhances the active-core optical confinement factor and the overall thermal conductivity of the device. A 10- \mu m \times 2 -mm ridge waveguide device that was mounted epitaxial side up displayed CW operation at temperatures up to 70~^{\circ } , substantially higher than for prior GaSb-based ICLs with hybrid claddings. When operated in pulsed mode at room temperature, the broad-area device processed from the same wafer had a threshold current density as low as 117 A/cm2, with a measured characteristic temperature of 60 K, which is the highest ever reported for ICLs operating near room temperature.