We describe recent work using metallic nanophotonic structures to achieve spectrally-selective absorption. At UV wavelengths, we have designed, fabricated, and characterized spectrally-selective filters for silicon detectors based on aluminum plasmonic gratings. At infrared wavelengths, we have designed linewidth-tunable plasmonic gratings for absorption enhancement.
I will present our latest demonstration of nano-photodetectors, integrated on CMOS, with ~250 GHz gain-bandwidth product and ~30 photon sensitivity. These show excellent agreement with our unifying theory of sensitivity in low-dimensional photodetectors, and present a pathway for much higher performance including room-temperature single-photon detection.