OPTICAL RESPONSE OF A PERFECT CONDUCTOR WAVEGUIDE THAT BEHAVES AS A PHOTONIC CRYSTAL

In this work, we consider a waveguide composed of two periodic, perfectly conducting, one-dimensional rough surfaces. This periodic system has a band structure similar in some aspects to a one-dimensional photonic crystal. However, our system has some additional interesting features. We calculate the band structure and the reflectivity of a corresponding finite waveguide. We found that the variation of the roughness amplitude and the relative phases allow to control at a certain degree the band structure of the system. Particularly, wide gaps can be obtained. It is even possible to obtain discrete modes for some frequency range and then the periodic waveguide acts as an unimodal filter. The system considered constitutes itself a photonic crystal whose band structure corresponds in many ways to a conventional photonic crystal but using just a single material. The key properties of this system are that it really constitutes a waveguide whose optical response is similar to that of a one-dimensional photonic crystal.