Chemical origins of optical self action effects in composite media

当激光束在固体介质中引导时，光会在一定距离内扩散（衍射）。在某些情况下，当光强度改变介质的折射率时，衍射效应会被抵消。在这种情况下，光束可能会作用于自身（光学自作用）以抵消衍射效应。如果光学自作用完全平衡衍射，我们就具有自聚焦，并且波会创建自己的波导以产生称为空间孤子的东西。像这样的孤子对光通信很感兴趣，因为它们可以长距离传播而不需要放大或校正。在某些介质中，例如某些有机聚合物和光敏玻璃，可以观察到类似孤子的行为。不同之处在于所创建的波导是永久性的。该研究项目旨在了解表现出永久折射率变化的介质中光诱导自刻印 (LISI) 背后的物理和化学过程。这个想法是仔细描述支持永久自书写的基础光化学。在这笔资助的期限内，作者将探索聚合物、聚合物复合材料、“分子二氧化硅”笼状聚合物复合材料和混合有机-无机玻璃中的 LISI。这项研究将影响我们对这种现象的起源以及如何使用它来制造光学集成电路器件的理解。

When a laser beam guides in a solid medium the light spreads out (diffracts) over distance. In some cases, the diffraction effect is counteracted when the intensity of light acts to alter the refractive index of the medium. In this case, the beam might act on itself (optical self-action) to counteract the effect of diffraction. If the optical self-action exactly balances diffraction we have have self-focusing and the wave creates its own waveguide to give something called a spatial soliton. Solitons like these are of interest to optical comunications because they can travel over long distances without the need of amplification or correction. In some media, like certain organic polymers and photosensitive glasses, soliton-like behaviour is observed. The difference is that the waveguide that is created is permanent. This research program seeks to understand the physical and chemical processes behind Light Induced Self Inscription (LISI) in media that exhibit a permanent refractive index change. The idea is to carefully describe the underlying photochemistry that supports permanent self-writing. Over the term of this grant, the author will explore LISI in polymers, polymer composites, "molecular silica" cage-polymer composites and hybrid organic-inorganic glasses. The research will have impact on our understanding of the origins of the phenomenon and how it might be used to make optical integrated circuit devices.