Observing the interaction of two light beams in a nano-suspension

Based on past experiment done by Dr. Chen [ 07], one can observe the nanoparticle-concentrating self-focusing phenomenon under certain conditions in a nano-suspension. This phenomenon does not have a clear theory yet. To investigate more about this nonlinear phenomenon, we perform a series of experiments. In this thesis, by designing various types of interactions between two light beams, we deepen the understanding of the nanoparticle-concentrating self-focusing phenomenon. Among these, by considering the relative positions and the sequence of the light, are: Inheriting: The light beams are launched at different moments without time overlaping, while the later one inherits the flow generated by the first one. Guiding: The two light beams are launched at the same position. Interaction: The two light beams are launched at the different locations at the same time. same location different location same time Guiding Interaction different time Inheriting Inheriting In the experiment, we can also vary the power and the beam size of the light beams. We only select the results that possess significant physical meanings to present in this thesis. From these experiment results, we conclude the condition for the formation of nanoparticle-concentrating self-focusing phenomenon. It must simultaneously satisfy at least two conditions, a stable flow field in the sample and the enough longitudinal difference of scattering force along the light beam.