For lighting applications demanding high brightness, a new type of LED-based light source has been developed, the high lumen density (HLD) source (luminance > 2·109 cd/m2). The performance can be improved further, among other things by optimizing the concentrator used as extraction optics. For this optimization, much insight is obtained by ray-tracing simulations. The efficiency can be improved by more than 20% if a high-index concentrator could be used. Furthermore, it is possible to optimize the shape of the concentrator. For a low-index (n ≈ 1.5) concentrator, the light leakage can be reduced, but the gain in useful light is only marginal. For a high-index (n ≈ 1.8) concentrator, the gain in useful light amounts to a few percent.

中文翻译：

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高流明密度源的提取光学器件

对于要求高亮度的照明应用，已经开发了一种新型的基于LED的光源，即高流明密度（HLD）光源（亮度> 2·109 cd / m2）。通过优化用作提取光学器件的聚光器，可以进一步提高性能。对于此优化，可以通过光线跟踪仿真获得很多见识。如果可以使用高折射率浓缩器，效率可以提高20％以上。此外，可以优化集中器的形状。对于低折射率（n≈1.5）聚光器，可以减少漏光，但是有用光的增益仅是很小的。对于高折射率（n≈1.8）的聚光器，有用光的增益为百分之几。