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Azobenzene polymer surface relief diffraction gratings were inscribed on relaxor ferroelectric Lead Lanthanum Zirconate Titanate (PLZT) thin films having a (9/65/35) composition. Resonance structures were observed in the reflected intensity spectra of a laser light beam onto these films, indicating coupling of the incident light. An ac electric field was then applied along the thickness of the PLZT films and an electro-optic modulation signal was measured as a function of the incidence angle of the laser beam. It was found that the resonance structures increased the modulation signal of the PLZT thin films at constant field amplitude.
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