论文标题
能量和波动流动在多模纤维中传播的光波的瑞利吉恩下降基础
Energy and wave-action flows underlying Rayleigh-Jeans thermalization of optical waves propagating in a multimode fiber
论文作者
论文摘要
波湍流理论预测，非线性波的保守系统可以表现出凝结的过程，该过程源于经典波的雷利 - 吉恩斯平衡分布的奇异性。考虑到多模纤维中的光传播，我们表明光凝结是由向高阶模式的能量流动的驱动的，而波动（或功率）的双向重新分布到基本模式和高阶模式。近场强度分布的分析提供了这种机制的实验证据。动力学方程还表明，波动和能量流可以通过朝着负温度平衡状态的热化倒置，其中高阶模式比低阶模式更为人群。此外，Bogoliubov稳定性分析表明，冷凝水状态是稳定的。
The wave turbulence theory predicts that a conservative system of nonlinear waves can exhibit a process of condensation, which originates in the singularity of the Rayleigh-Jeans equilibrium distribution of classical waves. Considering light propagation in a multimode fiber, we show that light condensation is driven by an energy flow toward the higher-order modes, and a bi-directional redistribution of the wave-action (or power) to the fundamental mode and to higher-order modes. The analysis of the near-field intensity distribution provides experimental evidence of this mechanism. The kinetic equation also shows that the wave-action and energy flows can be inverted through a thermalization toward a negative temperature equilibrium state, in which the high-order modes are more populated than low-order modes. In addition, a Bogoliubov stability analysis reveals that the condensate state is stable.
