A stabilized zinc diffused-proton bombarded (GaAl)As laser

A new (GaAl)As stripe laser in which a refractive index step is created by a zinc diffusion on both sides of a conventional proton stripe structure, called a diffused bombarded stripe (DBS) laser, is presented. This diffusion provides passive transverse guiding with a relatively simple technology. The index step can be adjusted by controlling the diffused zinc concentration in relation to the active region doping level. A self-alignment technique for the diffused and bombarded stripes reduces the current leakage through the diffused regions. Lasing threshold currents as low as those of conventional proton stripe lasers are obtained. A significant improvement of light-current linearity, transverse mode stability and longitudinal mode structure are observed with the DBS lasers.