High-output power GaSb-based diode laser with narrow n-type cladding layer

High output power GaSb-based diode lasers are critical component for 2 mu m laser systems. We compare four structures with different layer thickness combinations to optimize lower cladding layer thickness. Four structures have similar optical confinement factor of active region. As the lower cladding layer thins, the threshold current increases and the series resistance slightly reduces. Among the four structures, laser with 370nm waveguide layer and 1200nm n-type cladding layer functions the best. An output power of 1.21W at 3A is obtained, the threshold current is 0.11A, the series resistance is 0.25 Omega, the slope efficiency is 0.42W/A.