Surface Plasmon: Manipulating Light on the Nanoscale

Abstract

Nano-optics operates at the interaction of light and matter on the nanoscale, surpassing traditional diffraction limits and enabling the development of innovative tools for imaging, sensing, and comprehending complex interactions on the nanoscale. This thesis delves into the fundamental principles of nano-optics, with a focus on the utilization of surface plasmons to achieve nanoscale light concentration. Chapters I provide background knowledge covering surface plasmons and extra ordinary optical transmission induced by surface plasmons. Chapter II presents research tools and techniques employed in this thesis, including the Finite Difference Time Domain (FDTD) simulation method, focused ion beam, Ti:sapphire fs laser, and photoemission electron microscopy (PEEM). Chapter III introduces the development of interferometric time- and energy-resolved PEEM for investigating few-femtosecond nanoplasmonic dynamics. The ITR-PEEM system's capabilities are demonstrated on gold nanospheres, revealing strong plasmonic field enhancements and broadband plasmon resonance with distinct dynamics observable at an autocorrelation delay of about 1 femtosecond. Chapter IV explores the active tailoring of nanoantenna plasmonic fields using few-cycle laser pulses. This study focuses on understanding the spectral resonance manipulated by bowtie nanoantennas and proposes potential applications for attosecond pulse generation. Finally, chapter V explores the near- and far-field properties of polarization-dependent surface plasmon resonance in bowtie nano-aperture arrays (BNAs). Through optical transmission spectroscopy and PEEM, the physics underlying both polarization-dependent features and the determination of the resonant frequency of localized surface plasmon in BNAs with varying gap sizes are investigated. This thesis aims to provide insights into surface plasmons and their practical applications. As nano-optics continues to influence various scientific disciplines, this study strives to offer valuable perspectives on manipulating light at the nanoscale