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Developing a mild and efficient method to simultaneously enhance poling efficiency and temporal stability is meaningful and challenging for organic second-order nonlinear optical materials. In this paper, a new poly (aryl ether ketone) and chromophores functionalized with anthracene groups have been designed and prepared. Poling and crosslinking process could be separated by the mild and photo-initiated cycloaddition of anthracene group. As the UV–Vis spectrum, DSC and TGA curves, the networks had formed by 30-min irradiation of the Lower-power UV light which led little decomposition of dipolar chromophores. The maximum electro-optic coefficient (r33) of these polymers is 28.5 pm V−1 (at 1.3 μm), and the order parameter reaches 0.22. Moreover, the depolarization temperature of α peak, related to the dipole relaxation, has been increased to 129 °C after crosslinking, which is 17 °C higher than uncrosslinked ones. All these results indicated that the photo-crosslinking of anthracene exhibited promising potential for improving alignment stability and NLO activity at the same time.

A new strategy to tackle the orientation-relaxation of the chromophores was developed and used to prepare a film which was consisted of polymethyl methacrylate (PMMA) and photo-cross-linkable polyurethane oligomer (PU). The PU contained spindle-type chromophore and terminated with methacrylolyl groups as cross-linkable group. The chemical reaction process was characterized by infrared spectroscopy and the structure of reaction products were characterized by NMR spectroscopy. The surface morphology of the films was investigated by atomic force microscopy (AFM) images. The electro-optic (EO) coefficient of the prepared film was measured by using Teng-Man technique. The cross-linked films containing 15 wt% of the chromophore units displayed a high EO coefficient up to 41 pm/V. The 5% weight loss temperature was 228 °C for the film after photo-cross-linking. Compared with the uncross-linked films, their thermal and temporal stability were greatly improved.