[Seminar] Development of Time-Resolved Fluorescence Spectroscopy Using Heralded Emission Spectroscopy for Organic Light-Emitting Materials

Talk title: Development of Time-Resolved Fluorescence Spectroscopy Using Heralded Emission Spectroscopy for Organic Light-Emitting Materials

Speaker: Dr Nicola J. Fairbairn
JSPS Postdoctoral Fellow at The University of Electro-Communications in Tokyo
University of Glasgow, UK

Abstract:
A novel quantum light spectroscopy technique is presented for time-resolved photoluminescence (PL) lifetime measurements using heralded frequency-entangled photon pairs generated via spontaneous parametric down-conversion. By combining a hybrid superconducting nanowire single-photon detector and single photon avalanche diode (SNSPD-SPAD) coincidence detection system with a heralded photon detection scheme, PL lifetime measurements are demonstrated at excitation intensities several orders of magnitude lower than conventional pulsed-laser spectroscopy, whilst achieving superior background suppression and signal-to-noise ratio over short integration times.
By using a selection of organic light-emitting materials, it is found that heralded detection enables faster lifetime convergence and reduced measurement uncertainty compared to classical pulsed-laser excitation, even at significantly lower photon flux. The intrinsic temporal correlations of the entangled photon pairs provide a precise timing reference, mitigating common artefacts (such as scattering, background fluorescence, photon pile-up, and photobleaching) which are familiar challenges that fundamentally limit conventional TCSPC approaches.