Photovoltaic (PV) conversion is highly wavelength-dependent. The efficiency of a PV system is maximum when converting photons of energy close to the bandgap energy of solar cells. In a spectral-splitting solar cell system, an appropriately designed holographic lens provides wavelength-selective performance to disperse and concentrate a specific spectral region of solar radiation with appreciable diffraction efficiency. However, for holographic lenses, the angular range over that diffraction efficiency remains appreciable is limited. To overcome the difficulties associated with the limited acceptance angle (angular selectivity) of a single holographic lens, an investigation on the design aspect of a multiplexed off-axis holographic lens has been made for the collection and concentration of sunlight effectively over a wide angular range with appreciable diffraction efficiency. Processing parameters for a typical thick-phase holographic lens have been optimized to get the maximum value of the acceptance angle. Based on the theoretical design, a multiplexed hologram consisting of four angularly multiplexed holographic lenses of equal fringe spacing has been recorded. Experimental curves for the variation of diffraction efficiency with the angle of reconstruction have been presented to show the effectiveness of such multiplexed lens for solar tracking. Simulation results for the multiplexed holographic lens are also presented, which shows a good agreement with the experimental results. Results show that such off-axis multiplexed holographic lenses can advantageously be used for wavelength-selective performance with appreciable diffraction efficiency over a wide angular range.

中文翻译：

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用于聚光光伏中波长选择性宽接受角操作的离轴复用体积全息透镜的记录和分析

光伏 (PV) 转换高度依赖于波长。当转换的光子能量接近太阳能电池的带隙能量时，光伏系统的效率达到最大。在光谱分裂太阳能电池系统中，适当设计的全息透镜提供波长选择性性能，以可观的衍射效率分散和集中太阳辐射的特定光谱区域。然而，对于全息透镜，衍射效率仍然可观的角度范围是有限的。为了克服与单个全息透镜的有限接受角（角度选择性）相关的困难，对多路复用离轴全息透镜的设计方面进行了研究，以在宽角度范围内有效地收集和集中阳光，并具有可观的衍射效率。典型厚相位全息透镜的加工参数已经过优化，以获得接受角的最大值。基于理论设计，记录了由四个等条纹间距的角度复用全息透镜组成的复用全息图。衍射效率随重建角度变化的实验曲线已经给出，以显示这种多路复用透镜用于太阳跟踪的有效性。还给出了多路全息透镜的仿真结果，与实验结果吻合良好。