We report the characterization of a set of broad‐area semiconductor diode lasers with mid‐wave infrared (3–5 &mgr;m) emission wavelengths. The active region of each laser structure is a 5‐ or 6‐period multiple quantum well (MQW) with Ga0.75In0.25As0.22Sb0.78barriers and type‐II (broken‐gap) Ga0.75In0.25Sb/InAs superlattice wells. The cladding layers of each laser structure aren‐ andp‐type InAs/AlSb (24 A˚ /24 A˚) superlattices grown lattice‐matched to a GaSb substrate. By tailoring constituent layer thicknesses in the Ga0.75In0.25Sb/InAs superlattice wells, laser emission wavelengths ranging from 3.28 &mgr;m (maximum operating temperature=170 K) to 3.90 &mgr;m (maximum operating temperature=84 K) are obtained. ©1995 American Institute of Physics.