提出一种用于顺电相晶体Kerr系数和透射率的数字全息测量方法。该方法是数字记录晶体在不同电压时的全息图，再现数字全息图，得到晶体的复振幅信息，即振幅和相位分布。由晶体的振幅分布获得晶体的透射率；由相位分布得到不同电压差时的折射率变化量，从而计算得到晶体的电光系数。对顺电相Mn0.25%KLTN晶体进行了测量，记录了不同入射光模式以及不同电压时的数字全息图，得到了晶体透射率T和电光系数R11、R12。研究结果表明，该方法可用于顺电相晶体电光系数和透射率的测量，并且对晶体形状，照明光斑大小没有要求。

We present a method of measuring the transmittance and Kerr coefficients of a paraelectric crystal by digital holography. Digital holograms of the crystal with different voltage are recorded, the amplitude and phase information are extracted from numerically reconstructed image. The transmittance of crystal is measured by use of the amplitude information, and the spatial distribution of the induced refractive index change can be obtained by different phase of different voltage and the effective electro-optic coefficient is calculated by means of the refractive index change. Experiment has been carried out by examining a paraelectric phase Mn0.25%:KLTN crystal, and the research results show that the method presented in this paper is successful and feasible, which are irrelevant at the shape of crystal and the size of light source.