In this work, we use a special nonlinear dependence of dielectric permittivity to study theoretically the effect of a decrease in the nonlinear response in near-surface layers of a medium, which occurs with an increase in the amplitude of the electric field. We propose a model of nonlinearity in which the Kerr-type nonlinearity abruptly disappears with an increase in the field, and the dielectric permittivity becomes constant and independent of the field. Increasing the electric field leads to the formation of a local zone (optical domain) near the surface with linear optical properties where the dielectric permittivity becomes independent of the electric field. We formulate a nonlinear equation with stepwise dependence of the dielectric permittivity on electric field, and obtain its two types of exact solutions corresponding to the surface waves in media with positive (self-focusing) and negative (defocusing) nonlinear responses. We calculate and analyze the total power flows of thesurface waves of both types. We discuss in detail the features of the obtained solutions in comparison with previously published results. It is shown that the choice of a crystal with an appropriate nonlinear response makes it possible to increase or decrease the field intensity near the crystal surface with practically the same thickness of the near-surface layer with altered optical properties.

在这项工作中，我们使用介电常数的特殊非线性依赖性从理论上研究介质近表面层非线性响应降低的影响，这种影响随着电场幅度的增加而发生。我们提出了一种非线性模型，其中克尔型非线性随着场的增加而突然消失，介电常数变得恒定且与场无关。增加电场导致在表面附近形成具有线性光学特性的局部区域（光域），其中介电常数变得与电场无关。我们用介电常数对电场的逐步依赖来制定非线性方程，并获得其对应于具有正（自聚焦）和负（散焦）非线性响应的介质中的表面波的两类精确解。我们计算和分析了两种类型的表面波的总功率流。我们详细讨论了与以前发布的结果相比所获得的解决方案的特征。结果表明，选择具有适当非线性响应的晶体可以增加或减少晶体表面附近的场强，而近表面层的厚度几乎相同，但具有改变的光学特性。我们详细讨论了与以前发布的结果相比所获得的解决方案的特征。结果表明，选择具有适当非线性响应的晶体可以增加或减少晶体表面附近的场强，而近表面层的厚度几乎相同，但具有改变的光学特性。我们详细讨论了与以前发布的结果相比所获得的解决方案的特征。结果表明，选择具有适当非线性响应的晶体可以增加或减少晶体表面附近的场强，而近表面层的厚度几乎相同，但具有改变的光学特性。