A multi-wavelength laser array is achieved by using a wavelength selectable optical device as a feedback mirror for a plurality of lasers. The wavelength of reflected light from the optical device depends upon the parameters in the local reflection positions of the optical device along the direction as determined by guided-mode resonance. Thus, the multi-wavelength laser array is able to emit a plurality of laser beams with desired wavelengths, each within the gain curve of its active element.