Enhancement of Photonic Crystal All-Optical Diode Efficiency with a Subwavelength Layer.

In this paper, the effect of a subwavelength thin layer on all-optical diode action in a one-dimensional photonic crystal is investigated. The photonic multilayer structure is considered as (BA)⁶(AB)⁶C(AABB)⁶, where layers A and B are nonlinear and linear materials respectively, and C is a thin layer with positive or negative-index material. The results are shown that by introducing a thin layer with different optical properties the all-optical diode efficiency is controllable. In our numerical results, the transmission contrast of the structure, without the thin layer is obtained as 0.63, with a positive index material layer nearly zero and with a negative index material thin layer about 0.75. [ABSTRACT FROM AUTHOR]