a) a plurality of light emitting diodes positioned on a substrate; and

b) a plurality of flat lenses, a respective one of the plurality of flat lens being positioned a distance above a respective one of the plurality of light emitting diodes, each of the plurality of flat lenses comprising a plurality of annular segments having a common center, each of the plurality of annular segments comprising a prism shape microstructure having an exit facet having an angle with respect to a plane that is parallel to a plane of an emitting surface of respective ones of the plurality of light emitting diodes that is defined by the Fresnel equation and being configured to refract the light in a desired direction, and a facet oriented in the plane that is parallel to the plane of the emitting surface of respective ones of the plurality of light emitting diodes, and wherein a scaling factor of a height of each of the plurality of annular segments is in a range from 0.5 to 1.0, thereby providing a collimation of light exiting the plurality of flat lenses that exhibits a ratio of a difference in an angle where an intensity of exiting light at 10% of a maximum value and an angle where the intensity of exiting light is at 80% of the maximum value divided by an angle where the intensity of exiting light is at 50% of the maximum value that is greater than 0.7.