
m (AlGa)As,

m GaInAsP and AlGa-InAs, and 1.78 μm AlGaSb double-heterostructure (DH) lasers were prepared by molecular beam epitaxy. For AlGaAs DH lasers very low 300 K threshold current densities and long operating life (mean time to failure >10
6h at 300 K) were achieved and optical transmitters containing MBE-grown lasers have been field-tested. For lasers with lasing wavelength

m, MBE is in the development stage. The unique capabilities of MBE as an epitaxial growth technique and its important contributions to the field of optoelectronics are illustrated by a discussion of a new class of laser structures including quantum well heterostructure of GaAs/ Al
xGa
1-xAS and Ga
0.47In
0.53As/InP, double-barrier double-heterostructure, and graded-index waveguide separate-confinement-heretostructure lasers. These new lasers, made possible by MBE, have characteristics unmatched by conventional liquid phase epitaxial growth techniques.