Non-reciprocal optical reflection from a bidimensional array of subwavelength holes in a metallic film

Using simulations and theoretical arguments we investigate the specular reflection of a perforated gold film deposited on a glass substrate. A square lattice of cylindrical holes is assumed to produce the periodic lateral corrugation needed to hybridize the surface plasmons with radiative states. It is shown that, contrasting transmission approaches, a knowledge of the reflection on either side of the film provides separate information on the gold-vacuum surface plasmons and on the gold-glass interface plasmons. Recent experimental data on a specific implementation of this system are reexamined; these show a good agreement between the measured reflections and the simulations in both directions of incident wave probes. This confirms the importance of taking into account the reflection asymmetry in the far-field assessment of surface plasmons properties.