A laser television including a plurality of lasers for generating different wavelengths of interferential light; a scanner for displaying color images on a screen composed from the light; and a phase diffuser positioned between the lasers and the scanner for diffusing the light from the lasers according to the light's wavelength. The phase diffuser having a boundary surface, through which the light is outputted to the scanner. The boundary surface is slanted with a predetermined angle to regulate the range of diffraction of the light according to the wavelength.