A laser resonator is implemented by using the −1-st order reflection peaks of a sampled grating so that the multi-wavelength single mode light source array can be manufactured easily and economically. A multi-wavelength semiconductor laser array comprises a substrate; a plurality of laser stripes arranged with a predetermined space on the substrate, each being divided into two sections; a multiplicity of asymmetric sampled gratings distributed with sampling periods different from each other on the bottom of each active layer; and a number of effective refractive index changing layers, each arranged on one section of each laser stripe to make the Bragg wavelengths different at the two sections.