Abstract (eng)
Nanoparticles have found innumerable uses in physics, biology or medicine. As a result, various fabrication methods with precise control over the size and shape of the particles have been developed. One of them is called Laser printing of nanoparticles and is based on local melting of a donor material by irradiation with single pulses from a femtosecond laser.
In quantum optics, experiments with optically levitated nanoparticles offer a promising opportunity to test fundamental questions of quantum mechanics on a macroscopic level. Due to the decoupling between the experiment and its environment, these systems are also suitable as precise force and torque sensors. However, the controlled introduction of the nanoparticles into the optical trap represents a considerable experimental hurdle. This work is devoted to the discussion of a novel particle source for levitated optomechanics and gives an overview of the many facets of this rapidly growing field.
In the first part of the thesis the theoretical ground work for optical cooling of nanoparticles is worked out, starting with an introduction to Gaussian beam optics. Then, optical tweezers and feedback cooling are introduced, followed by a more in-depth treatise of optical resonators. This includes techniques for stabilizing the resonator and particle detection methods. In addition, the commonly used mechanisms for loading optical traps are presented.
In the second part, laser printing of nanoparticles is discussed as a potential experimental particle source. First, the working principle of the particle generation process is explained and experimental results of printed particles are presented. Subsequently, interferometric scattering microscopy as an in-situ observation method of the experiment is explored. Finally, an experimental setup is presented that combines the previously discussed techniques with an optical resonator in a vacuum-compatible configuration.