Chen Hongli, Zhang Youming, Zhang Baile, Gao Lei
College of Physics, Optoelectronics and Energy of Soochow University, &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Sci Rep. 2016 Feb 24;6:21741. doi: 10.1038/srep21741.
We provide a self-consistent mean field approximation in the framework of Mie scattering theory to study the optical bistability of a metallic nanoparticle coated with a nonlinear shell. We demonstrate that the nanoparticle coated with a weakly nonlinear shell exhibits optical bistability in a broad range of incident optical intensity. This optical bistability critically relies on the geometry of the shell-coated nanoparticle, especially the fractional volume of the metallic core. The incident wavelength can also affect the optical bistability. Through an optimization-like process, we find a design with broader bistable region and lower threshold field by adjusting the size of the nonlinear shell, the fractional volume of the metallic core, and the incident wavelength. These results may find potential applications in optical bistable devices such as all-optical switches, optical transistors and optical memories.
我们在米氏散射理论框架内提供一种自洽平均场近似，以研究涂覆有非线性壳层的金属纳米粒子的光学双稳性。我们证明，涂覆有弱非线性壳层的纳米粒子在很宽的入射光强度范围内呈现光学双稳性。这种光学双稳性关键取决于壳层包覆纳米粒子的几何形状，特别是金属核的分数体积。入射波长也会影响光学双稳性。通过类似优化的过程，我们发现通过调整非线性壳层的尺寸、金属核的分数体积和入射波长，可以得到具有更宽双稳区域和更低阈值场的设计。这些结果可能在诸如全光开关、光晶体管和光存储器等光学双稳器件中找到潜在应用。
