High-performance quantum cascade lasers grown by gas-source molecular beam epitaxy

Recent improvements in quantum cascade laser technology have led to a number of very impressive results. This paper is a brief summary of the technological development and state-of- the-art performance of quantum cascade lasers produced at the Center for Quantum Devices. Laser design will be discussed, as well as experimental details of device fabrication. Room temperature QCL operation has been reported for lasers emitting between 5 - 11 micrometers , with 9 - 11 micrometers lasers operating up to 425 K. We also demonstrate record room temperature peak output powers at 9 and 11 micrometers (2.5 W and 1 W respectively) as well as record low 80 K threshold current densities (250 A/cm2) for some laser designs. Finally, some of the current limitations to laser efficiency are mentioned, as well as a means to combat them.