Towards unstrained interband cascade lasers

We propose designs for the active region of an interband cascade laser by utilizing a combination of In(As,Sb) and (Ga,In)(As,Sb) materials in a type-II system for strain control and to eventually make the entire quantum well lattice-matched to GaSb or InAs substrates. Our k . p modelling results revealed that the tuning ranges for the oscillator strength of the optical transitions and the emission wavelength are beyond what is accessible with the commonly used strained system of InAs/GaInSb. Such a solution, combined with modifications in the passive device sections, can lead to the design and fabrication of a new class of fully unstrained devices operating in the mid-infrared range. (C) 2018 The Japan Society of Applied Physics