Absorption and stimulated‐emission data (77 and 300 K) are presented on a 50‐period, all binary A1As‐GaAs superlattice (SL) grown by metalorganic chemical vapor deposition (MO‐CVD). Laser operation of the SL is observed &Dgr;E∼h&slash;&ohgr;LObelow the absorption, which corresponds accurately to the lowest confined‐particle transistions determined from themeasured(transmission electron microscope, TEM) barrier and well sizes of LB∼120 A˚ and Lz∼160 A˚.