Highly Efficient Color Separation and Focusing in the Sub-micron CMOS Image Sensor

We report nanoscale metaphotonic color-routing (MPCR) structure that can significantly improve the low-light performance of a sub-micron CMOS image sensor. Fabricated on the Samsung's commercial $0.8\mu \mathrm{m}$-pixel sensor, MPCR structures separate the incident light energy into appropriate color pixels at high efficiency, yielding increased quantum efficiency up to +20%. Our experimental demonstration confirms a luminance SNR improvement of +1.22 dB under low light condition of 5 lux, accompanied with a comparably low color reproduction error and great angular tolerant response.