Zenginleştirilmiş ışık madde etkileşimleri için plazmonik nanoantenler ve grafen tabanlı ayarlanabilir nanofotonik aygıtlar

Focusing, manipulating and beaming of electromagnetic waves are important for many applications such as antennas, optical isolators, biological sensor, chemical sensors, and solar cells. There is an extensive research about the manipulation of light, and its interaction with different types of materials including subwavelength structures. However, manipulating light at the nanoscale has many difficulties due to the diffraction limit. In this thesis, we mainly focus on the characterization and experiments of subwavelength plasmonic structures. We investigated the spatial distribution of the electric field through subwavelength slits by using symmetric and non-symmetric periodic metallic grating structures in order to obtain one-way transmission, off-axis beaming, collimation and diode-like beaming. We also studied various plasmonic structures such as circular rings and fractal bowtie antennas. After combining them with Raman active molecules, we showed that these plasmonic structures can be used as efficient surface enhanced Raman spectroscopy substrates. Finally, we designed, fabricated and measured nanoantennas and split ring resonators on graphene in order to tune their optical response using the electrically controllable doping property of the graphene.