将CCD与电寻址液晶(EALCD)相结合,CCD作为记录介质,用于全息图和全息再现像的记录,EALCD则代替传统光学全息中曝光后的全息干板,用于数字全息图的再现。这种方法不仅避免了传统全息记录材料显影、定影等过程,也避免了全息材料非线性记录等缺点,并可以实现普通的数字全息较难实现的基于相位移法的位移测试。利用双曝光数字全息干涉法,在实验中对反射式被测物体生成的菲涅耳全息图进行了光学再现,并得到了准确的数据,验证了该方法的实用性。实验结果表明,CCD与EALCD相结合,可以实现数字全息图的光学再现,通过获得的干涉条纹,可精确测定物体位移量。

A new method of holography combining CCD and electrically addressed liquid crystal display (EALCD) is presented. CCD is used to record and reconstruct hologram,and EALCD is used to reconstruct the digital hologram in stead of holographic plate after exposure of traditional optical holography. This method avoids the developing,fixing processes of traditional hologram recording material,averts the shortcoming about nonlinear recording of holographic material,and can realize the displacement measurement based on phase shift method with which general digital hologram is unable to achieve. In order to certify the practicality of this method,double-exposure digital holographic interferometry has been used in experiment,and Fresnel hologram of reflective measured objects is obtained. The optical reconstruction is proceeded,and accurate experimental data has been gained. Experimental results indicate that the combination of the CCD and EALCD can realize the optical reconstruction of digital hologram,and the displacement of object can be accurately calculated through the interference fringes.