Recently, a new class of holographic recording materials based on photopolymerisable glass has been developed using the sol-gel technology. Photopolymerisable sol-gel materials have demonstrated excellent capability for volume holography due to their good optical quality and high dynamic range. Other advantages include high thermal and chemical stability, good dimensional stability and robustness because of their rigid matrix. However, the preparation period of non-tacky, dry layers suitable for holographic recording depends on both the sol-gel composition and the sample thickness, and varies from 5 to 21 days. Such a long gelation time is a bottleneck for mass production and this problem needs to be addressed to move the photopolymerisable glass to the next development stage allowing creation of real-world products.
This work presents a new photopolymerisable sol-gel glass capable of producing fully dried films using considerably reduced processing time (45 min at 100 °C).The new holographic sol-gel fulfils the required standards of high dynamic range (up to 0.003), high spatial resolution (currently achieved 5600 lines/mm), low scattering, good mechanical and dimensional stability that are necessary for volume holography. Moreover, for the first time the diffraction efficiency of transmission gratings and the spectral response of reflection gratings recorded in holographic sol-gel material under exposure to water have been characterised and their stability have been observed. This provides further perspectives for utilisation of the novel photopolymerisable glass for applications where stability of the photonic structure and its non-sensitivity to ambient conditions change are crucial.