[20p-H135-1~16] 3.9 Terahertz technologies

[20p-H135-7] Numerical approach to spiral wave plate based on moire-type metasurface

〇Seigo Ohno¹, Teruya Ishihara¹ (1.Tohoku Univ.)

Keywords:THz metamaterial

We found that a moire type meta-surface has a potential for a spiral phase plate. Two layers of metal disk arrays overlapped with rotating by a small angle make a moire super lattice for the considering electromagnetic wave. The spatial distribution of THz transmission intensity and phase spectra of the meta-surface are calculated with a commercial electromagnetic simulator. In the result, the first and second order of phase singularities were observed. Around the singularities, this moire type meta-surface serves as a spiral phase plate for the first and second order of optical vertices, respectively.