In-plane electro-optic anisotropy of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 thin films grown on (100)-cut LaAlO3

Strong electro-optical (EO) anisotropy has been measured in (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) [(1-x)PMN-xPT] single crystalline films epitaxially grown on (100)-cut LaAlO3 substrate, through using an improved dynamic alternating-current ellipsometric null EO detection technique with high accuracy. Large quadratic EO coefficients, which can be as large as 1.38x10(-16) (m/V)(2) in 0.67PMN-0.33PT film, were obtained in all the used compositions when electric field was applied along {110} directions. The strong EO anisotropy has been explained according to the structural relationship between ferroelectric polarization, input light polarization, and the applied electric field. (C) 1999 American Institute of Physics. [S0003-6951(99)04725-7].