A design for a micro-lens (i.e., a lens on the scale of micrometers) incorporates existing nanofabrication techniques and can be incorporated into High Concentrating Photovoltaic (HCPV), solar thermal collectors, and traditional flat PV systems. Using the theory of wave optics, the design is able to achieve a high numerical aperture, i.e., it can receive light over a wider range of angles. The design also reduces the distance the focal point shifts as the light source shifts; this eliminates the need for a tracking system in CPV and PV applications. Reducing the lens size also facilitates smaller, lightweight CPV systems, which makes CPV attractive for additional applications. Finally, these concentrators reduce the exchanging area of a typical flat solar thermal system where heat is received, which improves the overall system's efficiency and allows its use also during rigid winter time.