The Investigation Of Nano-optical Elements By 3D Boundary Element Method

The physical mechanism and manipulation of the interaction between light and matter are interesting problems for a long time and are investigated by physicists and engineers. Recently, the interaction between light and metallic material with nanometer feature size attracted more interests because of novel phenomena. For example, the extraordinary optical transmission (EOT) of light through an array of sub-wavelength holes has been reported by Ebbesen at al. in 1998. Furthermore, the collimation beam of light can be realized when the periodic sub-wavelength structure is etched on both side of the metal film and it indicates that it is possibility to break though the diffraction limit and confine the light within nanometer scale. However, there are many open questions, such as, the physical mechanism. On the other hand, the interaction between light and nano-particles also has attracted more and more attentions. The geometrical and physical parameters, such as, the size, the shape, the arrangement of nano particles and the material where the particles are located will affect the interaction, and the most concerned issue is the enhancement of local magnetic field and the selectivity of light frequency. But up to now, the research about the interactions whether between light and sub-wavelength metal construction or between light and nanometer particle construction is based on two-dimensional (2D) structure. In the actual design and application, all optical elements are three- dimensional (3D). If we simulate appositely 3D problem by the use of the 2D structure model, there will be prodigious difference between the theoretic results and the real problem. It is necessary to develop a 3D vector method to investigate exactly the extraordinary optical transmission based on three-dimensional structure. In this paper, I have educed the 3D surface integral equations based on the rigorous Maxwell's equation, and then have simulated various 3D structures of optical elements by solving the equations. The main content of this paper is as flowing:[1] The deduction of the rigorous vector surface integral equations.[2] The development of the computer programming and the check of correctness.[3] The rigorously numerical results for several models: light interact with single and double dielectric particles, individually, and with single and two metallic particles, respectively.