Robustness and Local Polarization Control of Plasmonic Antennas with Fabrication Errors

All-optical magnetic recording with circularly polarized light has attracted attention for ultra-high-speed magnetic recording. To obtain high-density magnetic recording, localized light over the diffraction limit is required. Nanoantennas have been designed to generate localized circularly polarized light for high-density all-optical magnetic recording system. The amplitude and phase of the localized light depend on the incident wavelength, shapes, and materials of antennas. To realize these practical systems, the antenna shape must be robust against fabrication errors. Therefore, we propose an antenna shape with high robustness against these errors. Furthermore, a control method for the amplitude and phase of localized light is proposed.