Hornung Thorsten, Nitz Peter
Opt Express. 2014 May 5;22 Suppl 3:A686-704. doi: 10.1364/OE.22.00A686.
Fresnel lenses are widely used in concentrating photovoltaic (CPV) systems as primary optical elements focusing sunlight onto small solar cells or onto entrance apertures of secondary optical elements attached to the solar cells. Calculations using the Young-Maggi-Rubinowicz theory of diffraction yield analytical expressions for the amount of light spilling outside these target areas due to diffraction at the edges of the concentrator Fresnel lenses. Explicit equations are given for the diffraction loss due to planar Fresnel lenses with small prisms and due to arbitrarily shaped Fresnel lenses. Furthermore, the cases of illumination by monochromatic, polychromatic, totally spatially coherent and partially spatially coherent light (e.g. from the solar disc) are treated, resulting in analytical formulae. Examples using realistic values show losses due to diffraction of up to several percent.
菲涅耳透镜作为主要光学元件，广泛应用于聚光光伏（CPV）系统中，用于将太阳光聚焦到小型太阳能电池上，或聚焦到附着在太阳能电池上的二次光学元件的入射孔径上。利用扬-马吉-鲁比诺维茨衍射理论进行的计算，得出了由于聚光菲涅耳透镜边缘的衍射而溢出这些目标区域的光量的解析表达式。给出了具有小棱镜的平面菲涅耳透镜和任意形状菲涅耳透镜的衍射损耗的显式方程。此外，还处理了单色、多色、完全空间相干和部分空间相干光（如来自太阳圆盘的光）的照明情况，得出了解析公式。使用实际值的示例显示，衍射损耗高达百分之几。
