The effect of the Kerr nonlinearity on the transmission through the nanoslit gold film

This paper has made a theoretical study of enhanced transmission through a gold grating with arrays of subwavelength slits filled with nonlinear Kerr medium. The results of the research are based on rigorous finite-difference time domain calculations. The resonance transmission peaks in the investigated wavelength range are produced as a result of the surface plasmon resonance collaborated with the localized waveguide resonance. The paper also gives a detailed analysis of the influence exerted by various factors: thickness, third-order susceptibility and line refractive index of the nonlinear medium filled in the gold slits arrays and the incident intensity to the transmission. It is found that the small changes of parameters such as medium thickness, third-order susceptibility and line refractive index of the nonlinear medium filled in the gold slits arrays as well as the incident intensity can bring great changes of lateral shift and magnitude variation of the transmission resonance peaks. The report proposes that these phenomena can be applied to designing precise optical switches.