Abstract
The potential inhomogeneities in actual excited semiconductors and the Fermi-statistical basis for the optical gain therein are recognized in the context of a composite-gain model. Spontaneous emission from a variety of physical processes arising in regions of differing excitation density is amplified by a smooth, broadband gain process, which is characterized by a width and peak position dependent on excitation density. A variety of poorly understood but generally observed characteristics of stimulated light emission from many semiconductor materials may be simply explained in terms of this model.