Electro-optic switch in ferroelectric thin films mediated by surface plasmons

We propose an optical switch in simple waveguide geometry with a metal thin film sandwiched between two layers of electro-optic materials. Its mechanism is based on the distinct responsive behaviors of two surface plasmon modes in the metal film to the cladding films. By exploiting the specific distribution of surface plasmon fields in metals, an effective optical switch with a very low crosstalk −27dB and a switching bias of 59kV∕cm is achieved for Ba0.5Sr0.5TiO3 ferroelectric films. The dependences of the optical switch’s crosstalk and switching bias on the geometric parameters of the structure are also analyzed.