Opt Lett. 2018 Jun 1;43(11):2700-2703. doi: 10.1364/OL.43.002700.
Recent experiments with pulse propagation in multimode graded-index fibers have shown a nonlinear improvement in beam quality, even in situations where dissipative processes such as Raman scattering play no significant role. In this Letter, numerical simulations of beam cleanup by third-order Kerr nonlinearities in a multimode fiber are used to demonstrate that in the absence of dissipative processes beam cleanup is crucially dependent on spectral/temporal disorder and does not occur in a continuous-wave model. This finding is in accordance with fundamental considerations on entropy.
最近在多模渐变折射率光纤中进行的脉冲传播实验表明，即使在不存在耗散过程（如拉曼散射）的情况下，光束质量也会得到非线性改善。在这封信中，我们使用多模光纤中的三阶克尔非线性的光束清洗数值模拟来证明，在不存在耗散过程的情况下，光束清洗关键取决于光谱/时间无序，并且不会在连续波模型中发生。这一发现符合关于熵的基本考虑。
