Guest Editorial Mini-Special Issue on International Quantum Cascade Lasers School and Workshop (IQCLSW 2016)

The papers in this special section were presented at the International Quantum Cascade Lasers School and Workshop (IQCLSW 2016). Quantum cascade lasers (QCLs) are unipolar optoelectronic devices that exploit optical transitions between engineered electronic subbands created in multiple coupled semiconductor quantum wells. The large number of nano metre thick semiconductor layers and the complexity of the overall structure, makes the QCL the most impressive demonstration of the capabilities offered by band structure engineering and state-of-the-art materials growth technologies.