论文标题
自我清洁多模束的连贯结合
Coherent combining of self-cleaned multimode beams
论文作者
论文摘要
低强度的光束来自具有斑点形状的分级指数，高模纤维，而在较高强度下，Kerr非线性可能会引起梁的自发空间自我清洁[1,2]。在这里，我们揭示我们可以生成两个自我清洁的光束，相互连贯性足够大，可以在非线性干涉仪的输出处产生清晰的稳定条纹图案。这两个梁由相同的输入激光器泵送，但被自清洗成独立的多模纤维。因此，我们证明，自我清洁机制通过无噪声参数过程保留了光束的相互连贯性。尽管与初始泵的连贯性直接相关，但即使在不同模式下获得的自我清洁，也没有额外的噪音，但非线性空间连贯性的出现是实现的，尽管纤维结构障碍源于固有缺陷或外部扰动。我们的发现可能会影响波动冷凝的理论方法[3-5]，并为相干束组合[6-9]开放新的机会。
A low intensity light beam emerges from a graded-index, highly multimode optical fibre with a speckled shape, while at higher intensity the Kerr nonlinearity may induce a spontaneous spatial self-cleaning of the beam [1,2]. Here, we reveal that we can generate two self-cleaned beams with a mutual coherence large enough to produce a clear stable fringe pattern at the output of a nonlinear interferometer. The two beams are pumped by the same input laser, yet are self-cleaned into independent multimode fibres. We thus prove that the self-cleaning mechanism preserves the beams' mutual coherence via a noise-free parametric process. While directly related to the initial pump coherence, the emergence of nonlinear spatial coherence is achieved without additional noise, even for self-cleaning obtained on different modes, and in spite of the fibre structural disorder originating from intrinsic imperfections or external perturbations. Our discovery may impact theoretical approaches on wave condensation [3-5], and open new opportunities for coherent beam combining [6-9].
