| Summary: | 碩士 === 國立臺灣大學 === 物理研究所 === 93 === Three-dimensional photonic crystals formed with face-centered-tetragonal (FCT) and face-centered-cubic (FCC) structures were researched by theoretical calculation and experimental measurement. We used optical fibers with diameter of 250 µm to construct photonic crystals in the terahertz region. The fibers were arranged in two close-packed layers and etched thinner for crossing layer by layer, and then an FCT structure with four layers was fabricated. By the computation with the finite-difference time-domain (FDTD) method, we found an absorption peak in our FCT specimen, and it may be the common behavior of FCT.
Furthermore, due to the self-assembling behavior, polystyrene nanospheres (PSNS) could congregate to a photonic crystal with FCC structure. By choosing the diameter of PSNS ranging from 199 nm to 299 nm, plus the computation of the plane-wave expansion (PWE) method and the measurement of the microscopic measurement system, we were successful to create photonic crystals whose tunable photonic bandgaps (PBG) covered the visible region. In this thesis, the absorption and reflection properties have been investigated near the photonic bandgap in FCT and FCC structures, respectively. A detailed compassion between theoretical calculation and experimental measurement will be included.
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