Monolithic homojunction diode lasers have been fabricated from vapor-grown Ga
1-xIn
xAs (

) mesa structures with grown optical facets. The Ga
1-xIn
xAs lasers have been operated at 77 K, and similar GaAs mesa devices have lased between 77 K and 300 K. Monolithic arrays of up to six mesa lasers on a single substrate have been operated with all lasers oscillating simultaneously.