飞秒表面等离激元脉冲群速度的控制

Control of slow group velocity of femtosecond suface plasmon polaritons

讨论了非线性克尔介质/金属波导中表面等离激元的慢光效应及群速度控制,利用时域有限差分方法进行了验证。结果表明,在接近波导的表面等离激元频率附近,产生了明显的慢光效应;在频率一定的情况下,群速度随着非线性介质相对介电常数的增大而减小。利用非线性克尔效应,对中心频率为400 nm的飞秒表面等离激元脉冲,实现了利用入射脉冲的峰值强度对群速度控制。这些研究结果为表面等离激元慢光效应在可调延迟线方面的潜在应用提供了理论依据。

The effects of slow light and control of group velocity about Kerr nonlinear medium/metal waveguide are discussed, and are confirmed using the finite difference time domain method. The results show that obvious effects of slow light occur near the frequency of surface plasmon polaritons, and the group velocity decreases with the in- creasing of relative dielectric constant of nonlinear Kerr medium in the case of fixed frequency. Exploiting the effect of nonlinear Kerr, the group velocity of the pulse with center wavelength 400 nm can be controlled by the peak in- tensity of input pulse. The results provide theoretical basis for slow light effects based on surface plasmon polaritons applying potentially in tuning optics delay line.