On the modified active region design of interband cascade lasers

The work has been supported by Project Widelase (No. 318798) of the 7-th Framework Program of the European Commission. The authors would like to acknowledge the National Science Centre of Poland for support within Grant No. 2011/03/D/ST3/02640.Type II InAs/GaInSb quantum wells (QWs) grown on GaSb or InAs substrates and designed to be integrated in the active region of interband cascade lasers (ICLs) emitting in the mid infrared have been investigated. Optical spectroscopy, combined with band structure calculations, has been used to probe their electronic properties. A design with multiple InAs QWs has been compared with the more common double W-shaped QW and it has been demonstrated that it allows red shifting the emission wavelength and enhancing the transition oscillator strength. This can be beneficial for the improvements of the ICLs performances, especially when considering their long-wavelength operation.Publisher PDFPeer reviewe