Nanoparticle structures obtained using photovoltaic tweezers and their applications in photonic devices

Abstract

The aim of this thesis work was to perform arbitrary 2D particle manipulation and trapping using optoelectronic photovoltaic tweezers, thus removing the existing limitations that seriously reduced their technological potential. To this end the z cut configuration proposed by Esseling et al. has been investigated in detail from the theoretical and experimental point of view. In particular, the patterning capabilities of z cut LiNbO3:Fe crystals have been investigated in order to obtain 2D nanoparticle patterns that can be used in different optical devices. The objectives of this research are: -To obtain high quality 2D nanoparticle patterns, as they are indispensable for future technique applications. -To calculate the distribution and time evolution of the fringe field and the dielectro and electrophoretic potentials generated on the surface of photovoltaic crystals under arbitrary light distributions in order to explain the features of the experimental patterns and to optimize the experimental conditions. -To develop a nanoparticle pattern transference process from the original LiNbO3:Fe crystal to any arbitrary substrate. -To fabricate photonic devices based on the nanoparticle patterns and analyse their performance.