High acousto-optic and electro-optic effects in relaxor ferroelectric single crystals and related device development.

摘要

The electro-optic and acousto-optic effects of Lead Zinc Niobate-Lead Titanate (1−x)Pb(Zn_1/3, Nb_2/3)O₃—(x)PbTiO ₃ (PZN-PT), and Lead Magnesium Niobate-Lead Titanate (1−x)Pb(Mg _1/3, Nb_2/3)O₃—(x)PbTiO₃ (PMN-PT) single crystals are new materials investigated for high performance piezoelectrics. Based on their extraordinary electromechanical properties and associated structure information, it is likely to also find the phase transition related high optical modulation ability in these crystals. In order to better understand the underlying nature of their phase transition behaviors, materials have been examined on their dielectric and piezoelectric properties.; In order to verify their optical properties, the characterization methods for electro-optic and acousto-optic effects are presented in detail. The measurement results show these new materials have both high electro-optic and acousto-optic coefficients. Using a phenomenology theory, the temperature independent electro-optic coefficients and relationship among acousto-optic coefficients are explained.; To fully demonstrate both excellent electromechanical and optical performances in these materials, a new ultrasonic transducer design is proposed with piezoelectric effect as transmitter and optical Fabry-Perot etalon as receiver. In order to realize nontuning interferometric measurement, a quadrature detection method is developed. Experimental results on the single element transducer demonstrate the feasibility of this new type of transducer. Conclusion and proposals for further work are presented.