Fig. 3
Broadband device results. a Electric field distribution of the device from 2.5-dimensional FDTD simulation results at different wavelengths. Scale bar, 100 µm. b Normalized histogram of photon counts versus time difference Δt measured for different wavelength photons from 600 nm to 1970 nm. The main peaks are from the TE modes while the minor peaks marked by the dashed circles are from TM modes. The histogram is recorded with the nanowire detector biased at 80% of its switching current ISW. c Comparison between experimentally measured Δt and the diffraction angle extracted from the simulation results. d Normalized photon counting rates (PCR) measured as a function of the bias current relative to the switching current of the device Ibias/ISW at wavelengths from 750 to 1970 nm. The complete saturation trend of the curves indicates a near-unity internal quantum efficiency of the nanowire detector over the whole spectrum. The histogram results are taken from Device C with double-nanowire detector, while the efficiency curves are measured from Device B with single-nanowire structure for better comparison between different wavelengths (see Supplementary Note 1)
