Interband cascade lasers for wavelength specific applications in the 3–4 µm spectral range

Interband cascade lasers (ICLs) are considered to be a very promising candidate for covering the mid-infrared wavelength range between 3 μm and 4 μm with just one type of semiconductor laser. Our contribution strengthens this thesis in terms of electro-optical results obtained from broad area and ridge waveguide ICL devices. A set of six ICLs with varied widths of the optically active InAs QWs shows emission from 2.97 μm to 4.16 μm without further changes to the underlying layout. Accompanied by photoluminescence measurements and theoretical calculations, a tuning rate of 0.55 μm per monolayer InAs and a linear temperature dependence of 1.88 nm/K from 150 K up to room temperature could be derived. The presented ICL results provide the means for device fabrication with high yield for applications dependent on a specific target wavelength.