Pulsed single-photon spectrometer by frequency-to-time mapping using chirped fiber Bragg gratings

摘要

A fiber-integrated spectrometer for single-photon pulses outside thetelecommunications wavelength range based upon frequency-to-time mapping,implemented by chromatic group delay dispersion (GDD), and precisetemporally-resolved single-photon counting, is presented. A chirped fiber Bragggrating provides low-loss GDD, mapping the frequency distribution of an inputpulse onto the temporal envelope of the output pulse. Time-resolved detectionwith fast single-photon-counting modules enables monitoring of a wavelengthrange from 825 nm to 835 nm with nearly uniform efficiency at 55 pm resolution(24 GHz at 830 nm). To demonstrate the versatility of this technique, spectralinterference of heralded single photons and the joint spectral intensitydistribution of a photon-pair source are measured. This approach tosingle-photon-level spectral measurements provides a route to realizeapplications of time-frequency quantum optics at visible and near-infraredwavelengths, where multiple spectral channels must be simultaneously monitored.