Data are presented showing that AlxGa1−xAs (x∼0.42) grown by metalorganic chemical vapor deposition (MO‐CVD) will operate as a photopumped laser to wavelengths as short as ∼6200 A˚ (77 °K). From the different spectral behavior of two separately photopumped epitaxial AlxGa1−xAs (x∼0.36) confining layers (1 and 0.3 &mgr;m thick) with an 80‐A˚ (and a comparison 200‐A˚) GaAs quantum‐well center layer, the recombination of hot electrons with holes collected in the quantum layer is used to estimate &Dgr;Ev.