We confirmed the effectiveness of light-trapping by forming concentric grating couplers (CGCs) inside a transparent sheet. A portion of the light incident to the CGCs is input-coupled and converted to the guided mode and is radiated from neighboring CGCs at a wider angle than the incident angle or even over the critical angle for both surfaces of the sheet. We demonstrated that three stacked sheets with multi-layered CGCs can trap an average of 19%–29% of the incident light at angles of 0 to 70 in the visible spectrum.

中文翻译：

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通过使用堆叠的同心光栅耦合器，为整个可见光谱提供高效的光捕获板

我们通过在透明片内形成同心光栅耦合器 (CGC) 来确认光捕获的有效性。入射到 CGC 的一部分光被输入耦合并转换为导模，并从相邻的 CGC 以比入射角更宽的角度辐射，甚至超过片材两个表面的临界角。我们证明了具有多层 CGC 的三个堆叠片材可以在可见光谱中以 0 到 70 度角捕获平均 19%–29% 的入射光。