Broad area quantum cascade lasers operating in pulsed mode above 100℃ at λ ～ 4.7 μm

We demonstrate a broad area（400 μm） high power quantum cascade laser（QCL）. A total peak power of 62 W operating at room temperature is achieved at λ~ 4.7 μm. The temperature dependence of the peak power characteristic is given in the experiment, and also the temperature of the active zone is simulated by a finite-elementmethod（FEM）. We find that the interface roughness of the active core has a great effect on the temperature of the active zone and can be enormously improved using the solid source molecular beam epitaxy（MBE） growth system.