摘要 |
A multiple junction photovoltaic cell is optically coupled to the Fresnel lens with teeth. The set of teeth within a given ring of a ringed pattern of teeth on the Fresnel lens may have 1) varying surface angles of different teeth across the lens, 2) varying refractive indexes of the different teeth or 3) a combination of both. The differing surface angles or refractive indexes of different teeth within a given ring of a ringed pattern of teeth establish multiple focal lengths aimed at five or more different axial target focal points within an anticipated zone of operation relative to the multiple junction photovoltaic cell to create a window of averaged intensity of light defined by the five or more different axial target focal points. |