Modeling nanoscale V-shaped antennas for the design of optical phased arrays

We present a simplified numerical method to solve for the current distribution in a V-shaped antenna excited by an electric field with arbitrary polarization. The scattered far-field amplitude, phase, and polarization of the antennas are extracted. The calculation technique presented here is an efficient method for probing the large design parameter space of such antennas, which have been proposed as basic building blocks for the design of ultrathin plasmonic metasurfaces. Our calculation is based on the integral equation method of moments and is validated by comparison to the results of finite-difference time-domain (FDTD) simulations. The computation time is approximately five orders of magnitude less than for FDTD simulations. This speed-up relies mainly on the use of the thin-wire approximation, whose domain of validity is discussed. This method can be generalized to more complex geometries such as zigzag antennas.