Chemical origins of optical self action effects in composite media

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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.