1.Measure the phase shift between the normal and the extraordinary light beam for different voltages applied to the PLZT-element for different electric field strengths. The half-wave voltage V (λ/2) is to be determined.

2.By plotting the square of the applied voltage versus the phase shift between ordinary and extraordinary beams, it is to be shown that the relation between the two quantities is approximately linear. From the slope of the straight line, the Kerr constant is to be calculated.