Scattering in random photonic networks

该项目的目的是研究在非线性存在下随机光学介质中的散射现象，并对相应的理论预测进行实验验证。我们希望构建和研究与技术相关且易于操作的模型系统，如光子网络和扭曲薄膜波导，它们以受控的方式实现不同的散射几何形状以及非线性相互作用。在光子网络中，散射中心由定向耦合器表示，其中光通过波导或光纤在不同耦合器之间无损耗地传输。由于这些连接器的长度不同，随机性开始发挥作用。我们将研究弱局域化，背散射和非线性引起的折射率变化的影响，以及在不同的连接和dimensions.Kerr膜波导的非线性的光子网络的增益和损耗可能会竞争与空间变化的随机折射率分布。我们将研究空间孤子的形成如何影响甚至抑制光在相应杂质上的散射，以及无序和非线性如何影响透射场振幅的极值统计，这个项目将对散射过程的动力学以及随机性和非线性之间的相互作用提供新的见解。

The aim of the project is the investigation of scattering phenomena in random optical media in the presence of nonlinearity and the experimental verification of respective theoretical predictions. We want to construct and investigate technically relevant and easy to handle model systems as photonic networks and distorted film waveguides, which realize different scattering geometries as well as nonlinear interaction in a controlled manner.In photonic networks scattering centers are represented by directional couplers, where the light is transmitted between the different couplers without losses via waveguides or fibers. Randomness comes into play due to varying length of these connectors. We will investigate weak localization, back scattering and the effect of nonlinearly induced index changes as well as of gain and loss in photonic networks of different connectivity and dimension.Kerr nonlinearities in AlGaAs film waveguides may compete with a spatially varying random index profile. We will investigate how the formation of spatial solitons influences or even suppresses the scattering of light on respective impurities and how the extreme value statistics of the transmitted field amplitudes is influenced by disorder and nonlinearity.This project will give new insights into the dynamics of scattering processes and in the interplay between randomness and nonlinearity.