AI 中文总结
研究在可见带宽固定时多通道光谱路由器的路由性能变化，通过延迟 - 带宽分析等，利用拓扑优化和模拟设计不同通道数的路由器，发现平均路由效率与子像素尺寸有关，最大效率随通道数下降，量化了光谱采样与光通量的权衡。
AI 中文摘要
逆设计光谱路由器可通过将不同波长引导至指定探测器子像素来实现紧凑型快照光谱成像，无需机械扫描或吸收滤光片。本文研究了在可见带宽固定时，随着光谱通道数量增加，路由性能如何变化。通过延迟 - 带宽分析关联通道数、最差通道效率和器件厚度，解释了生成多个空间上不同光谱输出所需不断增长的光学容量。然后利用基于伴随的拓扑优化和三维时域有限差分模拟，在匹配材料、带宽和厚度条件下设计了具有9、16、25和36个通道的TiO2/SiO2路由器。平均路由效率随子像素尺寸增加并趋于平稳，而接近平稳状态时的最大效率从9通道的97.0%单调降至36通道的82.3%。在固定通道数下，将波长间距压缩至8nm或重新安排波长到子像素的分配，效率变化不到1个百分点。这些结果表明，观察到的效率损失主要由波长相关路由约束的数量决定，而非波长间距或局部波长排列。研究结果量化了紧凑型快照光谱成像仪中光谱采样与光通量之间的权衡。
英文摘要
Inverse-designed spectral routers can enable compact snapshot spectral imaging by directing different wavelengths to designated detector sub-pixels without mechanical scanning or absorptive filters. Here, we examine how routing performance varies as the number of spectral channels increases while the visible bandwidth remains fixed. A delay-bandwidth analysis relates channel count, worst-channel efficiency, and device thickness, explaining the growing optical capacity required to generate many spatially distinct spectral outputs. We then use adjoint-based topology optimization and three-dimensional finite-difference time-domain simulations to design TiO2/SiO2 routers with 9, 16, 25, and 36 channels under matched material, bandwidth, and thickness conditions. The average routing efficiency increases with sub-pixel size and approaches a plateau, while the maximum near-plateau efficiency decreases monotonically from 97.0% for 9 channels to 82.3% for 36 channels. At a fixed channel count, compressing the wavelength spacing to 8 nm or rearranging the wavelength-to-sub-pixel assignment changes the efficiency by less than one percentage point. These results indicate that the observed efficiency penalty is governed mainly by the number of wavelength-dependent routing constraints rather than by wavelength spacing or local wavelength arrangement. The findings quantify the trade-off between spectral sampling and optical throughput in compact snapshot spectral imagers.
Comments19 pages, 5 figures
