Date of Award
Master of Science in Electrical Engineering - (M.S.)
Electrical and Computer Engineering
Karl D. Moeller
The transmission properties of metal meshes are studied for single meshes, photonic double layers and photonic crystals. Simulations are performed with the Flomerics Micro-Stripes program for light of infrared and millimeter wavelengths. The Micro-Stripes program solves Maxwell's equations numerically and, for simulations of the transmittance of metal meshes, has been proven as good as an experiment. Input data are the geometrical parameters, the indices of refraction and the conductivity, chosen according to the Drude model. The light is assumed to be at normal incidence and the simulation results are compared with experiments.
Single layers of inductive meshes are studied for a range of metal thicknesses and opening sizes. Rectangular structures of cross, square and circular shaped openings and hexagonal structures with hexagonal openings are discussed for the same length of cross and square shapes and diameters of circles and hexagonal openings. The resulting spectra are interpreted with resonance modes of the surface waves, appearing at wavelength range larger than the periodicity constant, the wave guide modes and Wood anomaly at wavelength equal to the periodicity constant, and the diffraction region at shorter wavelength. A very desirable filter characteristic with 10% band width and 84% transmission was obtained for circular opening.
Photonic double layers are two meshes with lined-up openings at different separations. The layers are chosen to be thick inductive meshes and the transmission studied over a range of separations smaller than the resonance wavelength of the meshes. The results show that tunable filters may be constructed with a particular separation range.
Photonic crystals are studied, made of metal spheres supported by a dielectric medium with index close to one. A layered structure is assumed, with layers considered as thick capacitive meshes. The transmittance at normal incidence is studied for photonic crystals of Simple Cubic, Body-centered Cubic and Face-centered Cubic structures. The simulations are performed and interpreted with resonance mode of one layer and stacking mode of many layers. The agreement with experiments is excellent.
Shah, Jay, "Photonic crystals composed of thick inductive and capacitive meshes" (2003). Theses. 659.