We present a theoretical study on optical properties of short-period InAs/GaSb type-II superlattices (SLs) which can serve for mid-infrared (MIR) detection. The miniband structure of such SLs is calculated using the Kronig–Penney model. On the basis of the energy-balance equation derived from the Boltzmann equation we calculate the optical absorption coefficient. The obtained results agree with recent experimental findings. Moreover, the dependence of the MIR absorption in InAs/GaSb type-II SLs on temperature and well-widths are examined.