A set of generalized calculated results are presented for both radiative and Auger rates in direct gap semiconductors. Emphasis is on materials with band gaps of 1.3 and 1.55 &mgr;m. The radiative and Auger components of the lifetime at threshold are calculated for several possible materials for a semiconductor laser at these wavelengths based on the best available data for the band structure of these materials. We find that the calculatedT0for these materials lie in the range 49 K–92 K.