Numerical study of high reflection coatings with negative and positive refractive indexes

In this communication, we intend to create a stratified coatings comprised of negative and positive refractive indexes, NRI and PRI, to achieve high reflection The emphasis of this work is on the reflection feature and how it can be increased Generally, quarter wave length longs of high and low refractive index media are applied to the substrate to form NRI-PRI multilayer stacks By choosing the proper indexes, the various reflected wave fronts can be made to interfere gainfully to generate a well-organized reflector. The reflectance peak depends on the ratio of refractive indexes of two media, as well as the number of stack pairs The coatings and computations are performed and determined using the theory of transfer matrix method. Numerical results of this work show that the coatings are effective for both parallel and perpendicular polarization components, and can be designed for a wide frequency range In addition, this communication also provides to be able to decrease/increase the frequency range to the desired band and to make size reduction in the layer number