Abstract: Microlens arrays include a substrate, an array of microlenses on a first side of the substrate and an aperture mask on a second side of the substrate. The aperture mask includes an array of apertures at optical axes of the lenses. A second array of apertures may be included in the aperture mask at randomized positions therein. The randomized apertures may be provided in the aperture mask by providing a diffusive layer between the aperture mask and the substrate, and directing coherent radiation through the lens array, the diffusive layer and aperture mask.

Abstract: Optical microstructures, such as microlenses, are fabricated by rotating a cylindrical platform that includes a radiation sensitive layer thereon, about its axis, while simultaneously axially rastering a laser beam across at least a portion of the radiation sensitive layer. The cylindrical platform is also simultaneously translated axially while it is being rotated. The amplitude of the laser beam is continuously varied while rastering. The optical microstructures that are imaged in the radiation sensitive layer can be developed to provide a master for replicating a microlenses.