We calculated band structures of (11¯00)-oriented GaN with various strains. We found that introducing anisotropic strain in thecplane separates heavy- and light-hole bands. We also found that a tensile strain in the (11¯00) plane makes the light-hole band topmost. These two effects result in a reduction in the density of states at the valence-band edge. In this way we can significantly reduce the transparent carrier density to generate gain. ©1997 American Institute of Physics.