Quantum Dot Localization with Time Resolved Super-Resolution Tracking Microscopy

A novel setup provides simultaneous measurement of the photoluminescence decay time and local position of single emitters with 100 ps time resolution. For the method, a pulsed laser excites a fluorophore positioned in the confocal optical probe region. The subsequent photons are collected with a high numerical aperture microscope objective and imaged onto a 2x2 array of optical fibers in the image plane. Each fiber is connected to one of four single photon counting detectors. To regulate the emitter position, a piezoelectric stage actively adjusts its location with proportional-based feedback from the four detector intensities, so the emitter remains in the center of the probe region. The time-dependent emission observed on the four detectors is used to monitor the spatial position of the emitter with approximately 10 nm precision. This study provides a foundation for later work that will investigate the structural basis of energy transfer among nanoparticles in higher order configurations.