A Shifted Waveguide Connector Combined with a Photonic Crystal Filter Designed by Transformation Optics

In this paper, transformation optics and photonic crystals have been introduced to design a shifted waveguide that can also be used as a filter. Instead of starting from an effectively homogeneous medium, we transform a regular photonic crystal into an elliptical one in physical space. Compared with a traditional waveguide, the simulations and calculations perfectly agree with the theoretical analytical model without any reflection and distortion. By taking advantage of the properties of photonic band gaps, the shifted waveguide can block some specific frequencies. We also composed a set of waveguide shifters without loss based on the proposed design. Full-wave electromagnetic simulations using detailed examples are performed to confirm the characteristics of the novel waveguide.

► Combine the transformation optics and photonic crystals to form a new kind of waveguide. ► The proposed new waveguide can be realized as a function of traditional PCs waveguide. ► The shifted waveguide can guide the waves from one waveguide to another without any reflection and distortion.