【摘要】 利用电场中液晶分子的可控双折射效应对制成电场可调的位相型衍射式菲涅耳波带片。对菲涅耳波带片的原理做了理论分析，测试了其最大衍射效率，给出不同电压Ｆ的不同衍射图像，并对衍射图像的周期性变化做了理论分析。更多还原

【Abstract】 Electrically controlled Fresnel phase waveband plate can be made by using the birefringence and the electric field adaptability of the liquid crystal molecule. The principleof the Fresnel waveband plate is analysed, and the maximum diffraction efficiency ismeasured. Diffraction pictures with different voltage applied are presented. Theoreticalanalysis on the periodic transformation of the diffraction picture is also made.更多还原