As single-photon imaging becomes progressively more commonplace in sensing applications such as low-light-level imaging, three-dimensional profiling, and fluorescence imaging, there exist a number of fields where multispectral information can also be exploited, e.g., in environmental monitoring and target identification. We have fabricated a high-transmittance mosaic filter array, where each optical filter was composed of a plasmonic metasurface fabricated in a single lithographic step. This plasmonic metasurface design utilized an array of elliptical and circular nanoholes, which produced enhanced optical coupling between multiple plasmonic interactions. The resulting metasurfaces produced narrow bandpass filters for blue, green, and red light with peak transmission efficiencies of 79%, 75%, and 68%, respectively. After the three metasurface filter designs were arranged in a ${64} \times {64}$ format random mosaic pattern, this mosaic filter was directly integrated onto a CMOS single-photon avalanche diode detector array. Color images were then reconstructed at light levels as low as approximately 5 photons per pixel, on average, via the simultaneous acquisition of low-photon multispectral data using both three-color active laser illumination and a broadband white-light illumination source.

中文翻译：

---

使用高效等离子体超表面马赛克滤镜的超微光彩色图像重建

随着单光子成像在诸如低光水平成像，三维轮廓和荧光成像等传感应用中逐渐变得越来越普遍，存在许多领域，例如在环境监测和环境监测中也可以利用多光谱信息。目标识别。我们已经制造了一个高透射率马赛克滤光片阵列，其中每个光学滤光片都是由在单个光刻步骤中制造的等离子体超表面组成的。这种等离子超表面设计利用了椭圆形和圆形纳米孔阵列，从而在多个等离子相互作用之间产生了增强的光学耦合。产生的超表面产生了用于蓝，绿和红光的窄带通滤光片，其峰值透射效率分别为79％，75％和68％。$ {64} \ times {64} $格式的随机马赛克图案，此马赛克滤镜直接集成到CMOS单光子雪崩二极管检测器阵列中。然后，通过同时使用三色有源激光照明和宽带白光照明源同时采集低光子多光谱数据，以平均低至每个像素约5个光子的光水平重建彩色图像。