Phase-controlled directional switching of surface plasmon polaritons via beam interference


A novel method for switching the direction of surface plasmon polarition (SPP) launching is proposed by Seung-Yeol Lee et al. (pp. 273-279). The principle behind the switching mechanism is based on the relative phase difference between the reference beam and the control beam. Selective guidance of the direction of SPP can be explained by the composition of the charge parity that is induced near the slit edge, which is caused by interference created by two incident beams. The switching of SPP launching direction could be implemented by simple phase modulation of the control beam when the slit parameters satisfy the specific conditions at the designed specific wavelength. An experimental demonstration, in good agreement with numerical results, shows that our configuration of SPP switching can be operated by a quite simple interaction