Broadband metamaterial-based single-photon detectors with near-unity absorption

Here we show that incorporating broadband metamaterial perfect absorbers into a photodetector's active area can improve device efficiency and speed. We show an optical absorption of 93% across the spectral region where commercially available Si and InGaAs detectors have poor efficiencies. Combining the metamaterial perfect absorber with an avalanche photodiode layer stack, we aim to realize a high efficiency portable single photon avalanche diode with high timing resolution ideal for quantum ranging, quantum communication, and medical imaging applications.