Deep Zn diffusion from a ZnP2source has been used to fabricate stripe-geometry double-heterostructure GaInAsP/InP diode lasers with emission wavelengths in the1.2-1.3 mum range. These devices exhibit good electrical and optical confinement. For sufficiently narrow stripe widths (<10 mum), emission is usually single mode and linear. CW outputs up to ∼8 mW per facet have been observed. In initial life tests, two Zn-diffused lasers have operated CW at room temperature for over 5000 h without appreciable degradation.