Stable transverse mode oscillation in planar stripe laser with deep Zn diffusion

The guiding mechanism in a planar stripe laser with deep Zn diffusion under the lasing conditions was investigated both theoretically and experimentally. The conditions necessary to realize refractive index guiding depend on a combination of electron and hole concentrations. The lasers under refractive index guiding, whose stripe width is less than twice the diffusion length, with an adequate combination of electron and hole concentrations, show stable fundamental transverse mode oscillation up to three times the threshold current level.