An Experimental Study on X-Shaped Branching Waveguide in Two-Dimensional Photonic Crystal Structure

Photonic crystal or electromagnetic band gap structure are expected to play important roles in optical signal processing and optical fiber communications, because of its unique and sensitive characteristics for wavelength based on photonic band gap theory. In such signal transmission and processing, high density multiplexing in wavelength domain is expected due to its sensitiveness with respect to optical wavelength. This is important to improve capacity of information transmission in the future photonic network. In this paper, experiments based on X-shaped branching wave guide reported by using scale models in microwave frequency. Comparisons of the parameters which could be indicated as Q factor and extinction ratio were summarized. Filtering characteristics of each structure were measured to be certified that X-shaped wave guide can be operated as filter components with good separation in wavelength division multiplexing (WDM) systems.