The Superlens And Superbending Effects In Photonic Crystals

Negative refraction is a special unnatural phenomenon in left-handed materials. The superlens effect, which is based on the negative refraction, has attracted a lot of interesting recently because of the special sublength imaging property. The negative refraction can be generated not only in left-handed materials but also in photonic crystals, which makes the photonic crystals become a good choice to realize the superlens effect. In this thesis, the two-dimensional photonic crystal slab with hexagonal lattice structure as the superlens imaging system was theoretically studied, the sublength imaging property of the superlens imaging system was investigated, where the minimum resolution was 0.4λ.Additionally, the effect of proper air-photonic crystal slab surface termination to superlens image's quality was discussed, and the optimization value of the surface termination was obtained by simulation result. The imaging property of two-superlens system was studied. The image forming condition of the N-superlens system was found to be equal to a one-superlens system, where the conclusion was proved by simulation in a two-dimensional photonic crystal slab superlens with triangle lattice structure, using finite-difference time domain method.The superbending propagation characteristics of Gaussian beam in a graded two dimensional photonic crystal, which was formed by gradually changing the permittivity of one of the square lattice photonic crystal consisting materials, were investigated. The air-graded photonic crystal slab surface termination was optimized and the relationship of superbending lateral shift and input wavelength in TE and TM mode was discussed. This kind of graded photonic crystal can be used not only in designing open waveguide, but also in beam splitter and polarization-indifference waveguide device.In experiment, combining the holography lithography technique and polymer dispersed liquid crystal, the two dimensional photonic crystals with triangle lattice structure using special designed single optical element prism were fabricated, where the obtained lattice constants were 1894 nm and 500 nm, respectively. The advantages of using holography polymer dispersed liquid crystal to fabricate photonic crystals include low cost, easy process, and electrically tunable property. This method can be used to make two dimensional and three dimensional photonic crystals with large area and has a lot of application potential.