The design of an optical waveguide coupler has several challenges, such as reflection losses at the interfaces of the coupler, material complexity for optical applications, and the coupling between arbitrary materials at ...

different approaches. The waveguides theory is used in the first approach and the transmission line-based metamaterials theory is used in the second approach. Using the above-mentioned resonator and with regard to its analysed characteristics, two antennas...

A slab metamaterial lens with a refractive index of −1 is capable of producing a perfect image, since it transfers all the plane waves from the object plane to the image plane without creating any distortion in their amplitudes and phases. However...