Theory and Experiments of Plasmonic Optical Components for Nano Writer
Date Issued
2007
Date
2007
Author(s)
Lin, Ding-Zheng
DOI
en-US
Abstract
Due to optical diffraction limits, the focal spot size is influenced by the incident wavelength and the numerical aperture of a lens. In order to shrink the size of the focal spot, scientists continuously develop all kinds of techniques, which include immersion lithography, annular illumination, and selectively recording the longitudinal field (Ez), and so on. However, the high cost of light source and the rarity of lens material at shorter wavelength obstruct the development of lithography techniques.
In 1998, Professor T. W. Ebbesen discovered the extraordinary transmission and re-triggered the worldwide research interests on plasmonic optics. In this thesis, we used the theory of plasmonic optics to design new optical components. We proposed many concepts to design a novel optical head, including metal surface grating on metal (MM structure), dielectric surface grating on metal (DM structure), multi-slits structure (MS structure), subwavelength annular aperture structure (SAA structure)......etc. We also performed experiments to verify the optical properties and feasibilities of optical head continuously.
In the section of simulations, we proposed a complete simulation process, including easy estimation on the beaming angle of emitted light by using Rigorous Coupled Wave Analysis (RCWA) method, using Finite-Difference Time-Domain (FDTD) method to calculate the electric field distribution, etc. The simulation results agree well with our experiments. These simulations not only can help us predict the unknown phenomena but also provide us with the related parameters needed to design a plasmonic lens.
In the section of experiments, we used inverted microscope to observe directional beaming phenomena, and used near-field scanning optical microscope (NSOM) to measure the near-field and far-field optical properties of a subwavelength annular aperture (SAA). We not only found the interference fringe of surface plasmon existed at near-filed of the silver SAA structure, but surprisingly discovered the emitting light through the silver SAA structure has characteristics of high transmission energy, subwavelength focal spot, and long depth of focus. These unique optical properties make plasmonic lens one of the best choices for miniature lens.
In short, the surface plasmon offers a possibility to manipulate light in microscopic world and provides us with a potential to create new research fields at the age of nanotechnology.
Subjects
表面電漿
奈
米光學
光學頭
貝索
光束
指向性出射
近場光學
surface plasmon
nano optics
optical head
Bessel beam
directional beaming
NSOM
Type
thesis