Dynamic Illumination Microscopy for Fluorescence Lifetime and Quantum Nano-Imaging

Scientific context
Fluorescence lifetime is a powerful observable to probe local biochemical or
electromagnetic environments. It carries information about molecular interactions
(FRET, tension, pH…) but also about the local density of optical states (LDOS), a
fundamental quantity in nanophotonics and quantum electrodynamics that governs
spontaneous emission.
Super-resolution microscopy (Nobel Prize 2014) enabled the localization of single
emitters with nanometric precision, yet lifetime information is still mainly acquired using
cameras or confocal TCSPC, at the cost of speed, photon loss and limited multiplexing.
We are developing a new approach of dynamic illumination microscopy, where position,
lifetime and spectral information of single emitters are time-encoded in the illumination
rather than in the emission image.
Objective of the postdoctoral project
The postdoc will contribute to the development of a new generation of dynamic
illumination FLIM microscopy, applicable to:
– Bio-imaging at the nanoscale: mapping chemical and mechanical cues in living
cells (tension, pH, FRET);
– Nanophotonics and quantum optics: measuring LDOS fluctuations near
plasmonic antennas, photonic crystals or disordered media;
– Quantum emitters: exploiting single-photon emission and antibunching to retrieve
orientation, lifetime and LDOS of quantum dots, NV centers, or other solid-state
emitters.
The goal is to build and test an instrument capable of: generating time-modulated
structured illumination, detecting photons in TCSPC mode with single-photon
detectors, and retrieving simultaneously the nanometric position (x,y,z) and the
fluorescence lifetime τ of a unique emitter.
Profile of the candidate
– PhD in physics, optics, photonics, or a related field.
– Skills: Optical microscopy or ultrafast optics, TCSPC / FLIM / photon statistics,
Quantum emitters (quantum dots, NV centers, etc.), MATLAB / Python for data
reconstruction.

– Mainly experimentalist
– Curiosity for bio-imaging and/or nanophotonics and quantum optics.
Environment
The postdoc will join the Langevin Institute (ESPCI Paris – CNRS), in a multidisciplinary
environment bridging advanced microscopy, time-varying optics and wave physics and
biological collaborations and nanofabrication.
Practical information
– Duration: 12 to 24 months (renewable)
– Start date: Flexible (2025–2026)
– Location: ESPCI Paris – Institut Langevin (1 rue Jussieu, Paris 5)
Application: CV + motivation letter + reference(s) to: emmanuel.fort@espci.fr