Negative Refraction And Imaging Properties Research Of Hexagonal Honeycomb Structure Photonic Crystals

The basic characteristic of photonic crystal (PhC) is has the photonic band gap, preventing light from propagating in certain directions with specified frequencies, providing a very good method for people to control the photon. With the further research of photonic crystal materials, people proved that meet certain conditions of photonic crystal is kind of very good negative refraction materials both in experiment and theory, has good negative refraction effect. This thesis mainly studies the hexagonal honeycomb structure photonic crystal negative refraction and imaging properties.In chapter1, first of all, this thesis introduced the concept of photonic crystal, described the common preparation method and basic characteristics of photonic crystal, then explained the mechanism of negative refraction phenomenon, finally introduced the domestic and foreign research progress of photonic crystals with negative refractive phenomenon. Chapter2mainly introduced electromagnetic theory and numerical analysis method of photonic crystals, emphasis in two of the most commonly used method:plane wave expansion method and finite difference time domain (FDTD). Chapter3studies the negative refraction properties of photonic crystals, first introduced some basic concepts which necessary to explain before the analysis of photonic crystal negative refractive properties, illustrated the difference between the equivalent index of refraction negative refraction phenomenon and the equivalent negative index of refraction, then detailed analysis of the influence of two-dimensional photonic crystal negative refraction phenomenon in several parameters, which included dielectric cylinder radius, photonic crystal thickness, the location of the point source, dielectric cylinder dielectric constant, and so on. With the increase of the radius and dielectric constant of the dielectric cylinder, the full-width-at-half-maximum (FWHM) is decrease, we could think the increase of the radius and dielectric constant of the dielectric cylinder would improve the focusing resolution of photonic crystal negative refraction imaging in a certain extent; with the increase of the thickness of photonic crystal, light would weaken and even invisibility, however, the negative refraction phenomenon is always existed; only when the light source located in the near field, evanescent wave can be restored completely, it tended to produce more perfect negative refraction imaging phenomenon. Finally emphasis introduced the negative refraction in honeycomb and triangular lattice photonic crystals formed by holographic lithography.Finally, chapter4gave some methods in improving the focusing resolution of photonic crystal negative refraction imaging. Firstly introduced several methods has been published, then emphasis discussed the way that improve the focusing resolution of photonic crystal negative refraction imaging with hollow component structure, it is found that, in contrast of a hexagonal photonic crystal consisting of solid dielectric cylinders of the same radius, the photonic crystals with hollow components can be used to optimize the all-angle negative refraction. Numerical simulations showed that the transmission efficiency and resolution of image can be enhanced by changing the radii of the hollow air rods.In conclusion, this thesis mainly studies the hexagonal honeycomb structure photonic crystal negative refraction and imaging properties, included the negative refraction in honeycomb and triangular lattice photonic crystals formed by holographic lithography. Gave some methods in improving the focusing resolution of photonic crystal negative refraction imaging, emphasis discussed the way that improve the focusing resolution of photonic crystal negative refraction imaging with hollow component structure.