Department of Electrical and Computer Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92023, USA.
Phys Rev Lett. 2018 Jun 15;120(24):243904. doi: 10.1103/PhysRevLett.120.243904.
We study the propagation of surface plasmon polaritons (SPPs) on a metal surface which hosts a thin film of a liquid dielectric. The Ohmic losses that are inherently present due to the coupling of SPPs to conductors' electron plasma, induce temperature gradients and fluid deformation driven by the thermocapillary effect, which lead to a nonlinear and nonlocal change of the effective dielectric constant. The latter extends beyond the regions of highest optical intensity and constitutes a novel thermally self-induced mechanism that affects the propagation of the SPPs. We derive the nonlinear and nonlocal Schrödinger equation that describes propagation of low intensity SPP beams, and show analytically and numerically that it supports a novel optical spatial soliton excitation.
我们研究了在金属表面上传播的表面等离激元（SPP），该金属表面上承载着一层液体电介质薄膜。由于 SPP 与导体的等离子体电子的耦合而固有存在的欧姆损耗会引起温度梯度和由热毛细效应驱动的流体变形，从而导致有效介电常数的非线性和非局域变化。后者扩展到最高光强度区域之外，构成了影响 SPP 传播的新型热自诱导机制。我们推导出描述低强度 SPP 光束传播的非线性和非局域薛定谔方程，并通过分析和数值模拟表明，它支持新型光空间孤子激发。
