The Raman effect, inelastic scattering of light by lattice vibrations (phonons), produces an optical response closely tied to a material’s crystal structure. Here we show that resonant optical excitation of IR and Raman phonons gives rise to a Raman-scattering effect that can induce giant shifts to the refractive index and induce new optical constants that are forbidden in the equilibrium crystal structure. We complete the description of light-matter interactions mediated by coupled IR and Raman phonons in crystalline insulators—currently the focus of numerous experiments aiming to dynamically control material properties—by including a forgotten pathway through the nonlinear lattice polarizability. Our work expands the toolset for control and development of new optical technologies by revealing that the absorption of light within the terahertz gap can enable control of optical properties of materials over a broad frequency range.

中文翻译：

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通过红外共振拉曼效应对材料光学特性的超快控制

拉曼效应，即晶格振动（声子）对光的非弹性散射，产生与材料晶体结构密切相关的光学响应。在这里，我们展示了 IR 和拉曼声子的共振光学激发产生了拉曼散射效应，该效应可以引起折射率的巨大变化并引起平衡晶体结构中禁止的新光学常数。我们完成了对晶体绝缘体中耦合 IR 和拉曼声子介导的光-物质相互作用的描述——目前是众多旨在动态控制材料特性的实验的重点——包括通过非线性晶格极化率的被遗忘的路径。