面向成像系统感知的信息最优颜色路由器的逆设计
Imaging-system-aware color routers optimized for imaging information
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中文总结 AI 辅助
该研究针对相机成像系统的实际照明条件，逆设计了SiN颜色路由器，发现其在低信噪比下的图像信息携带量优于彩色滤光片阵列，并提出了光瞳平均路由纯度0.32的设计目标。
中文摘要 AI 辅助
纳米光子颜色路由器（CR）通常被优化为在单一平面波正入射条件下将预设的RGB波段导向标记的子像素。但相机并不满足这两个前提：在镜头后方，每个传感器位置接收到的是空间非相干、数值孔径有限的光瞳分布，该分布会随视场位置倾斜；且携带颜色图像信息最多的四个测量值不一定类似RGB滤镜。我们在真实传感器施加的倾斜幅度和方位角的、随视场变化的成像系统照明集合下，逆设计了一种单刻蚀SiN CR，且评分标准并非RGB路由效率，而是四个原始测量值携带的、关于重构CIE XYZ图像的成像信息。在该照明集合下重新评分后，平面波优化的设计会丧失大部分原本被认可的路由对比度，因此平面波下最优的结构未必是相机所感知的结构：优化所用的光源会改变所选设计。在该照明集合下，CR收集的电子数是彩色滤光片阵列（CFA）的2.8倍，但倾斜锥会使每个排序光斑扩散，导致更少的光落在正确位置：轴上通过率为0.96，而CFA为0.33；路由纯度为0.17，而CFA染料为0.50。两种器件在绿色位置信噪比13.7 dB（读出噪声1.5 e- rms）处达到平衡，低于该值时，CR携带的颜色图像信息多于CFA。要在全光条件下达到与参考CFA和相机模型的性能对等，需要光瞳平均路由纯度为0.32，我们将此作为该架构的设计目标。
英文摘要
Conventional nanophotonic color routers are typically optimized under idealized, normal plane waves. However, this standard assumption fails in real-world imaging-system environments, where structures are illuminated by converging light cones and field-dependent chief-ray angles. Here, we present an imaging-system-aware, end-to-end inverse-design framework that directly maximizes the mutual imaging information $\Iimg$ preserved by a single-layer silicon nitride color router under realistic pupil illumination. By analytically embedding the optimal reconstruction decoder directly inside the gradient loop, we co-design the optical nanostructures and the digital recovery pipeline. To scale this approach across a full sensor, we exploit the $D_4$ symmetry of the square pixel lattice, tiling $48$ distinct sensor-field regions using only six unique lithographic masks. Our optimized router is predicted to collect $2.8\times$ more photoelectrons than a conventional color-filter array. Consequently, under low-light conditions, below a green-site signal-to-noise ratio of $13.7$~dB, the color router preserves superior image information compared to the color-filter array; evaluated from its measured routing fractions together with the modeled throughput, the fabricated device reproduces this crossover at $11.1^{+2.1}_{-2.3}$~dB. This marks the first experimental demonstration, from measured routing and a modeled throughput, of a single-layer nanophotonic color router achieving a performance crossover against the color-filter array. These results establish that next-generation flat optics must shift from isolated device efficiency toward system-level co-design optimized under physical imaging-system-pupil geometry.
发表机构
- Chungnam National University（忠南国立大学）
- Seoul National University（首尔国立大学）
机构由 AI 辅助整理，请以论文原文为准。
