Abstract: A method and apparatus for generating a beam of light having extended depth of focus. The apparatus comprises, for instance, a binary phase mask that generates a diffraction pattern including a bright main ring and a plurality of side-lobe rings, an annular aperture mask that passing only a portion of the diffraction pattern, and a lens that causes light passing through the annular aperture to converge toward and cross an optical axis. Where the converging light crosses the optical axis, constructive interference takes place, thereby generating a beam of light that has extended depth of focus.

Abstract: A method and apparatus for generating a beam of light having extended depth of focus. The apparatus comprises, for instance, a binary phase mask that generates a diffraction pattern including a bright main ring and a plurality of side-lobe rings, an annular aperture mask passing only a portion of the diffraction pattern, and a lens that causes light passing through the annular aperture to converge toward and cross an optical axis. Where the converging light crosses the optical axis, constructive interference takes place, thereby generating a beam of light that has extended depth of focus.