Midya Bikashkali, Konotop Vladimir V
Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
Centro de Física Teórica e Computacional and Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, Campo Grande 2, Edifício C8, Lisboa 1749-016, Portugal.
Phys Rev Lett. 2017 Jul 21;119(3):033905. doi: 10.1103/PhysRevLett.119.033905. Epub 2017 Jul 18.
We reveal the existence of continuous families of guided single-mode solitons in planar waveguides with weakly nonlinear active core and absorbing boundaries. Stable propagation of TE and TM-polarized solitons is accompanied by attenuation of all other modes, i.e., the waveguide features properties of conservative and dissipative systems. If the linear spectrum of the waveguide possesses exceptional points, which occurs in the case of TM polarization, an originally focusing (defocusing) material nonlinearity may become effectively defocusing (focusing). This occurs due to the geometric phase of the carried eigenmode when the surface impedance encircles the exceptional point. In its turn, the change of the effective nonlinearity ensures the existence of dark (bright) solitons in spite of focusing (defocusing) Kerr nonlinearity of the core. The existence of an exceptional point can also result in anomalous enhancement of the effective nonlinearity. In terms of practical applications, the nonlinearity of the reported waveguide can be manipulated by controlling the properties of the absorbing cladding.
我们揭示了在具有弱非线性有源芯和吸收边界的平面波导中存在连续的单模孤子族。TE和TM偏振孤子的稳定传播伴随着所有其他模式的衰减，即波导具有保守和耗散系统的特性。如果波导的线性谱具有例外点，这种情况发生在TM偏振时，原本聚焦（散焦）的材料非线性可能会有效地变为散焦（聚焦）。这是由于当表面阻抗环绕例外点时，所携带的本征模的几何相位导致的。相应地，有效非线性的变化确保了尽管芯具有聚焦（散焦）的克尔非线性，但仍存在暗（亮）孤子。例外点的存在还可能导致有效非线性的异常增强。就实际应用而言，所报道波导的非线性可以通过控制吸收包层的特性来操纵。
