利用双曝光全息干涉场测物体微小位移

双曝光法是通过两次曝光将标准物光波前和变化后的物光波前,按不同时刻记录在同一张全息图上,形成两个一级干涉场,再现时,两个物光波面形成二级干涉场。通过计算机模拟,并结合实例计算,阐述了二级干涉场与微小位移、光场相位变化及转动角之间的关系。结果表明,用双曝光全息法测刚性漫反射物体时所产生的条纹出现在定域的空间曲线附近,而定域的锐度取决于观测系统的孔径。

Measuring Small Displacement of Objects by Using Double-Exposure Hologram Interference Field

Double-exposure method is a technique in which a standard object is exposed twice and the wavefronts reflected from the object before and after the change are recorded on the same hologram at different time.As a result,two first-order interference fields are produced without the introduction of a reference plane.A second-order interference field is created by the two wavefronts during reconstruction process.The relationship among the second-order interference field,small displacement,light phase change and rotation angle is invesgated by using experiments combined with computer simulation.The small displacements of rigid diffuse objects are measured using double-exposure hologram.Experimental results show that the stripes of the objects appear in the vicinity of the localized space curves,and their sharpness depends on the aperture of the observing system.