The Role of Polarization on 2D Plasmonic Crystals

In this paper, the polarization effects on surface plasmon resonance (SPR) in azimuthally rotated 2D square lattice plasmonic crystal (PCL) are reported. By controlling the polarization angle (α) of the incoming beam, the SPR coupling strength can be fully enhanced when optimized α is used for different momentum lattice vectors (x-, y-axis and diagonal direction). This value can be obtained by adjusting the polarization angle until the deepest dip in SPR reflectivity spectrum can be observed. This will lead to a much easier way for determining the optimum surface plasmon polariton excitation condition for each crystal momentum in 2D PCL.