BROADBAND PLASMONIC SURFACES AND APPLICATIONS Rüştü Umut Tok Mechatronics Engineering, PhD Dissertation, 2014 Thesis Jury Assoc. Prof. Dr. Kürşat Şendur (Thesis Supervisor), Prof. Dr. Pınar Mengüç, Assoc. Prof. Dr. Burç Mısırlıoğlu, Assoc. Prof. Dr. Cleva Ow-Yang, Assoc. Prof. Dr. Güllü Kızıltaş Şendur Date &Time:26/09/2014 & 8:30 AM Place: FENS 2008 Keywords: Plasmonic, Broadband, Nano-antenna, Metasurfaces Abstract Broadband plasmonic structures are emergent need for many practical applications including, thin-film photovoltaics, non-linear optics, surface enhanced spectroscopy techniques, single molecule spectroscopy and detection, near-field imaging, pulse shaping, and optical information processing. However, plasmonic structures generally have narrow and sharp resonances at quantized frequencies. In the last years, there is a tremendous effort to invent novel designs and physical mechanisms to supply the increasing demand for broadband plasmonic structures. In this dissertation various broadband plasmonic structures are investigated. Several novel broadband nano-antenna designs are introduced, their physical mechanisms are interpreted and several practical applications are demonstrated.