Research On The Optical Properties Of Left-handed Materials

Studies of left-handed materials open a series of new challenging problems for theoreticians as well as for experimentalists. The complete understanding of the properties of left-handed materials requires the reevaluation of some well-known facts of the electromagnetic theory. There are no formulas with negative permeability in classical textbooks of electromagnetism. Application of the existing formulas to the analysis of left-handed materials may lead to some strange results. The theory of electromagnetic field has to be reexamined assuming negativeεandμ. So, guided by this point, we performed some studies relative to left-handed materials. The main contents of this dissertation are described as follows.(1)The transfer function for left-handed materials slab is derived, and the effects of parameter deviations on the transfer function are numerically calculated. The numerical simulation shows that the transfer function is sensitive to the parameter deviations, and that the requirements of perfect lens on the parameter deviations are exacting. Therefore, it is very difficult, if not impossible, to obtain perfect lens for engineering industry.(2)We first derive the transfer matrix for the bilayer structure composed of left-handed and right-handed materials, from which the dispersion relation of the one-dimensional photonic crystal composed of alternative left-handed and right-handed materials can be derived.(3)Based on the transfer matrix for the bilayer structure, we compute the density of states along the axis of the finite one-dimensional photonic crystal, which is constructed out of N such bilayer structures periodically. The computations show that, under some conditions, there appear some unusual densities of states in the band gaps. These unusual densities of states are due to the discrete propagation modes peculiar to the photonic crystal composed of alternative left-handed and right-handed materials, and can be used to make very narrow filters totally different from any conventional types of filters.(4)From the dispersion relation of the one-dimensional photonic crystal with...