Institute of Physical and Theoretical Chemistry

Single Quantum Emitters & Microcavities

The miniaturization process for a variety of applications has reached a level where one have to handle single molecular or even atomic structures. Now the question is: Is it not only possible to arrange single quantum structures but also to control the optical properties of these single particles?

The answer is yes, and our experimental results demonstrate that we are already capable to determine and control intra-molecular processes. This is achieved in a very simple and elegant way: a confocal microscope is used to observe the desired changes of single quantum emitters placed in a tunable microresonator, while higher-order laser modes are applied to make these changes visible (e.g. change of the transition dipole momentum).

Actual experiments of our group can be divided into the following topics:

  • Single molecules in a tunable microresonator
  • 3D orientation of the transition dipole moment of single semiconductor quantum dots (Si/SiO2, CdSe/ZnS core/shell and SiO2 systems)
  • Tautomerism studies of single molecules (for example octaethylporphin)
  • Organic and inorganic nanostructured host-guest materials containing dye molecules or nanoparticles

Results of confocal imaging of single quantum emitters using higher-order laser modes, or what we call a "breakfast in the nano-world": coffee beans, doughnuts, and bonbons