Tailoring the optical properties at the micro- and nanoscale is key to enable new experiments in the field of quantum optics and biophotonics. To this end, I use my strong background in numerical simulations as well as nano- and microfabrication techniques together with the expertise in spectroscopy, linear and nonlinear optics to enable and conduct experiments.
Scintillator-based X-ray imaging is a powerful technique for noninvasive real-space microscopic structural investigation such as synchrotron-based computed tomography. The resolution of an optical image formed by scintillation emission is fundamentally diffraction limited. To overcome this limit, stimulated scintillation emission depletion (SSED) X-ray imaging, based on stimulated emission depletion (STED) microscopy, has been recently developed. This technique imposes new requirements on the scintillator material: efficient de-excitation by the STED-laser and negligible STED-laser excited luminescence. In this work, luminescence depletion was measured in several commonly-used Ce3+, Tb3+, and Eu3+ - doped scintillators using various STED lasers. The depletion of Tb3+ and Eu3+ via 4f-4f transitions was more efficient (Ps = 8…19 mW) than Ce3+ depletion via 5d-4f transitions (Ps = 43…45 mW). Main origins of STED-laser excited luminescence were one- and two-photon excitation, and scintillator impurities. LSO:Tb scintillator and a 628 nm cw STED-laser is the most promising combination for SSED satisfying the above-mentioned requirements.
Chip-Based All-Optical Control of Single Molecules Coherently Coupled to a Nanoguide
Pierre Tuerschmann,
Nir Rotenberg,
Jan Renger,
Irina Harder,
Olga Lohse,
Tobias Utikal,
Stephan Goetzinger,
Vahid Sandoghdar
The feasibility of many proposals in nano quantum-optics depends on the efficient coupling of photons to individual quantum emitters, the possibility to control this interaction on demand, and the scalability of the experimental platform. To address these issues, we report on chip-based systems made of one-dimensional subwavelength dielectric waveguides (nanoguides) and polycyclic aromatic hydrocarbon molecules. We discuss the design and fabrication requirements, present data on extinction spectroscopy of single molecules coupled to a nanoguide mode, and show how an external optical beam can switch the propagation of light via a nonlinear optical process. The presented architecture paves the way for the investigation of many-body phenomena and polaritonic states and can be readily extended to more complex geometries for the realization of quantum integrated photonic circuits.
