三维物体空间再现技术中的全息图计算

Computer-generated hologram calculation for spatial reconstruction of three-dimensional object

在简要论述三维物体计算全息技术理论的基础上,对具有代表性的三维物体全息计算方法的原理和技术要点进行了重点论述。采用层析法、菲涅耳波带法、多视角投影合成全息法等3种方法进行了三维物体全息图的计算,并利用LCR-2500空间光调制器及650 nm的150 mW半导体激光器对层析法计算的三维物体全息图进行了光电再现,对其它两种方法获得的三维物体全息图进行了数值再现,并对3种计算方法各自的特点和局限性进行了具体的分析。在对目前三维物体计算全息技术中存在的硬件和算法等关键问题进行分析的基础上,讨论了提高三维物体计算全息图效率和质量的有效途径。

The basic theories for Computer-generated Hologram（CGH） calculation of 3D objects were described,and the principles and key techniques of several typical approaches to CGH calculation of 3D objects were analyzed. Three types of methods including tomographic approach, Fresnel zone approach and multi-view image synthesizing approach were used to calculate CGHs for 3D objects. Sub- sequently, an electro-holographic display experiment for CGH of 3D object calculated by tomographic approach was performed using a LCR-2500 spatial light modulator and a 650 nm diode laser with power of 150 mW. Numerical reconstruction results were also obtained from the CGHs calculated by other two approaches. Then the characteristics and limitations of the three calculation methods for 3D CGHs were analyzed. Some key problems associated with hardware and algorithms were also analyzed, and several approaches were discussed on improving the calculation efficiency and the quality of CGH.