Time-varying optical media, whose dielectric properties are actively modulated in time, introduce a host of novel effects in the classical propagation of light, and are of intense current interest. In the quantum domain, time-dependent media can be used to convert vacuum fluctuations (virtual photons) into pairs of real photons. We refer to these processes broadly as “dynamical vacuum effects” (DVEs). Despite interest for their potential applications as sources of quantum light, DVEs are generally very weak, presenting many opportunities for enhancement through modern techniques in nanophotonics, such as using media which support excitations such as plasmon and phonon polaritons. Here, we present a theory of weakly modulated DVEs in arbitrary nanostructured, dispersive, and dissipative systems. A key element of our framework is the simultaneous incorporation of time-modulation and “dispersion” through time-translation-breaking linear response theory. As an example, we use our approach to propose a highly efficient scheme for generating entangled surface polaritons based on time-modulation of the optical phonon frequency of a polar insulator.

中文翻译：

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色散纳米光子学中的卡西米尔光

时变光学介质的介电特性随时间被主动调制，在光的经典传播中引入了许多新效应，并且引起了当前的强烈兴趣。在量子域中，时间相关介质可用于将真空波动（虚拟光子）转换为成对的真实光子。我们将这些过程广义地称为“动态真空效应”(DVE)。尽管对它们作为量子光源的潜在应用很感兴趣，但 DVE 通常非常弱，通过现代纳米光子学技术提供了许多增强的机会，例如使用支持激发的介质，如等离子体和声子极化子。在这里，我们提出了任意纳米结构、色散和耗散系统中弱调制 DVE 的理论。我们框架的一个关键要素是通过打破时间平移的线性响应理论同时结合时间调制和“色散”。例如，我们使用我们的方法提出了一种基于极性绝缘体的光学声子频率的时间调制来产生纠缠表面极化子的高效方案。