Johlin Eric
Western University, Mechanical and Materials Engineering, 1151 Richmond Street, London, N6A 3K7 ON, Canada.
iScience. 2021 Mar 5;24(4):102268. doi: 10.1016/j.isci.2021.102268. eCollection 2021 Apr 23.
Standard color imaging utilizes absorptive filter arrays to achieve spectral sensitivity. However, this leads to ∼2/3 of incident light being lost to filter absorption. Instead, splitting and redirecting light into spatially separated pixels avoids these absorptive losses. Herein we investigate the inverse design and performance of a new type of splitter which can be printed from a single material directly on top of a sensor surface and are compatible with 800 nm sensor pixels, thereby providing drop-in replacements for color filters. Two-dimensional structures with as few as four layers significantly improve fully color-corrected imaging performance over standard filters, with lower complexity. Being fully dielectric, these splitters additionally allow color-correction to be foregone, increasing the photon transmission efficiency to over 80%, even for sensors with fill-factors of 0.5. Performance further increases with fully 3D structures, improving light sensitivity in color-corrected imaging by a factor of 4 when compared to filters alone.
标准彩色成像利用吸收滤光片阵列来实现光谱灵敏度。然而，这会导致约三分之二的入射光因滤光片吸收而损失。相反，将光分离并重新导向空间上分离的像素可避免这些吸收损失。在此，我们研究了一种新型分光器的逆向设计和性能，该分光器可由单一材料直接印刷在传感器表面顶部，并且与800纳米的传感器像素兼容，从而为彩色滤光片提供直接替换方案。仅四层的二维结构就能显著提高全彩色校正成像性能，优于标准滤光片，且复杂度更低。由于这些分光器完全是电介质的，因此还可以省去色彩校正，即使对于填充因子为0.5的传感器，也能将光子传输效率提高到80%以上。全三维结构可进一步提高性能，与单独的滤光片相比，在彩色校正成像中光灵敏度提高了4倍。
