Fluorescent Holographic Fringes with a Surface Relief Structure Based on Merocyanine Aggregation Driven by Blue-violet Laser.

Stability and integration are the goals for developing photonic devices. Spirooxazines have the property of photoinduced merocyanine-aggregation in polymer matrix, which can be applied to fluorescence emission and stable information storage. Although visible light coherent radiation with UV-assist has been used to achieve polarization-modulated holographic memory in spirooxazine doped PMMA films, the complexity of optical systems is increased and the aggregation ability of merocyanine is decreased. Here, we report that fluorescent holographic gratings with a surface relief structure can be inscribed in the film via sole irradiation of 403.4 nm. Time-dependent photo-anisotropy and holographic dynamics were both investigated with different power densities of the near-UV laser. The non-exponential photokinetics was explained by the sequential formation of mono- and aggregate-merocyanine molecules. The appearance of merocyanine aggregates is found to be beneficial to the long-term holographic memory with fluorescent emission. This work provides a research strategy for the integrity of storage, display and micro-fabrication of organic functional-devices.