论文标题
非线性波模式耦合的超级散射
Superradiant Scattering from Nonlinear Wave-Mode Coupling
论文作者
论文摘要
散布在自我振荡模式下的波可以表现出超高或外部谐波激发的净扩增。从理论上预测了这种源于模式和入射波之间的非线性耦合而引起的这种外来行为，并在这项工作中首次实验证实。我们提出了一种非线性波模式耦合的通用理论，该理论类似于[Fan等，J。Opt。 Soc。是。 A 20，569（2003）]。使用超级散射器的可复制的空气声实现被用来测试该理论的预测。结果表明，可以利用非线性波模式耦合来准确调整波导中侧腔的反射和透射系数。用于描述这种类型的超高的理论框架适用于非声学系统，可用于设计无损散射设备。
Waves scattered at a self-oscillating mode can exhibit superradiance, or net amplification of an external harmonic excitation. This exotic behavior, arising from the nonlinear coupling between the mode and the incident wave, is theoretically predicted and experimentally confirmed for the first time in this work. We propose a generic theory of nonlinear wave-mode coupling, which is derived in analogy to the temporal coupled-mode theory of [Fan et al., J. Opt. Soc. Am. A 20, 569 (2003)]. A well-reproducible aeroacoustic realization of a superradiant scatterer was used to test the theory's predictions. It is shown that the nonlinear wave-mode coupling can be exploited to quasi-passively tune the reflection and transmission coefficients of a side cavity in a waveguide. The theoretical framework used to describe this type of superradiance is applicable to non-acoustic systems and may be used to design lossless scattering devices.
