4pi Photon Atom Coupling

Effiziente Kopplung von Licht und einzelnen Ionen

The interaction strength of light and a single atomic dipole is determined by the electric field component parallel to the transition dipole moment. In free space, this field component is maximized when a pure electric-dipole wave is incident onto the atom.
We attempt this optimum coupling scenario by focusing a suitable mode with a deep parabolic mirror onto a Yb ion. The ion is positioned in the mirror's focus by means of a dedicated ion trap. Efficient coupling of the focused field and the ion is tested in e.g. measuring the phase shift imprinted onto a coherent state or by exciting the ion with faint light pulses. For the latter experiment, one has to take guidance from time-reversal symmetry arguments which require the excitation pulses to have an exponentially rising envelop.

Nanopartikel in optischen Pinzetten

Efficient coupling of light to solid-state quantum targets by focusing from full solid angle necessitates mounting the targets without degrading the quality of the focal spot. We solve this difficulty by trapping nano-particles with optical tweezers. In proof-of-principle experiments we trap colloidal dot-in-rod nano particles. Furthermore, the deep parabolic mirror facilitates the efficient collection of photons emerging from a quantum emitter.
Our optical dipole trap is generated in the same way as the dipole modes employed in our coupling experiments, i.e. by focusing with a deep parabolic mirror. As a result, the trap stiffness and the depth of the trapping potential approach the optimum figures obtainable for focusing in free space. This makes our set-up also interesting for opto-mechanical experiments.

Nichtlineare Optik in extrem kleinen Foki

The very tight focusing encountered when illuminating a deep parabolic mirror with a suitable light mode is not captured by the standard approximations usually applied in non-linear optics. Moreover, there exist no experimental investigations of non-linear optics under such extreme focusing conditions at all.
We investigate third-harmonic generation in noble gases under such boundary conditions, testing the borders of validity of the predictions of non-linear optics in the paraxial regime and looking for new effects.

MPL Newsletter

Bleiben Sie auf dem Laufenden mit unserem Newsletter!
Der MPL Newsletter informiert Sie über aktuelle Forschungsergebnisse und spannende Neuigkeiten aus dem Institut.

Aktuelle Ausgabe: Newsletter No 13 - Oktober 2018

Hier finden Sie vorherige Ausgaben des Newsletters.

 

Max-Planck-Zentren und -Schulen