Fast data-driven spectrometer with direct measurement of time and frequency for multiple single photons

We present a single-photon-sensitive spectrometer, based on a linear array of 512 single-photon avalanche diode detectors, with 0.04 nm spectral and 40 ps temporal resolutions. We employ a fast data-driven operation that allows direct measurement of time and frequency for simultaneous single photons, time- and frequency-stamping each single-photon detection. Our results combine excellent temporal and spectral resolution. We benchmark our result against the Heisenberg Uncertainty Principle limit of hbar/2 for time and energy, and we are only a factor of 10 above it, despite the simplicity of our experimental setup, including room temperature operation. This work opens numerous applications in both classical and quantum photonics, especially when both spectral and temporal properties of single photons are exploited.