Self-assembled Ga1-xInxNyAsl-y, quantum dots (QDs) were grown on GaAs by solid source molecular beam epitaxy using a radio-frequency plasma assisted nitrogen source. High GaInNAs QD density (10(10) -10(11) cm(-2)) was obtained for different In and N composition (0.3 less than or equal to x less than or equal to 0.7,y less than or equal to 0.01). The effect of surface coverage on dot density, dot size, and optical property was studied in detail. Adjusting the bandgap confinement by incorporating a GaNAs strain-reduction layer into the GaInNAs dot layer was found to extend the emission wavelength by 180 nm. Room-temperature pulsed operation is demonstrated for a Ga0.5In0.5N0.01As0.99 QD laser emitting at similar to 1.1 mum. (C) 2003 Elsevier B.V. All rights reserved.