【摘要】 由一束球面波和一束平面波或者两束球面波干涉所形成的体全息光栅,由于其光栅矢量在全息图体积内是随位置的变化而变化的,所以被称为非周期型的体光栅。主要研究了用于体全息三维成像系统的非周期体光栅的深度选择特性。根据叠加的原理,将非周期体光栅看作多个固定周期的基元体光栅的叠加,结合耦合波理论分析非周期体光栅的衍射特性。采用这一方法,利用Matlab软件模拟,研究了两束记录光夹角对所记录的非周期体光栅深度选择性的影响和在两束记录光夹角相同时,球面参考光体全息成像系统及平面参考光体全息成像系统深度选择性的差别,最后在光折变晶体材料中进行非周期型和周期型体光栅的记录和再现,对模拟结果进行了实验验证。更多还原

【Abstract】 The volume grating formed by interfernce of one spherical wave and a planar wave is aperiodic due to its grating vector changes within the volume of hologram.The depth selectivity of aperiodic volume holographic gratings is investigated as spatial-spectral filters in volume holographic imaging systems.The diffractive characteristics of aperiodic volume holographic grating is analyzed by regarding it as an ensemble of local planar gratings cooperating with Kogelnik coupled-wave method.The depth selectivity of an aperiodic and a periodic grating are simulated respectively,and the effect of recording angle on the depth selectivity of aperiodic grating is simulated.Experiments of recording and retrieving volume gratings in photorefractive crystal are designed and implemented in order to verify our simulation results.更多还原