Plasmonic half-waveplate based on gold nanoslit and its application to ultrasmall radial polarization converter

We proposed and developed high aspect gold metasurface in order to improve the transmittance of plasmonic micro half-waveplate. Expected transmittance reaches 60% from the FDTD calculation. The metasurface is fabricated through electron beam litography (EBL) and lift-off process. Fabricated retarder was evaluated using polarization microscopy. Achieved retardation and transmittans were 144 degrees and from 25 to 40%, respectively. Four metasurface half-waveplates were arranged and applied to an ultrasmal radial polarization converter.