大视角数字全息的研究

Digital Holograms with Large Viewing Angle

提出一种新的数字全息方法实现大视角彩虹全息的制作。根据两步法彩虹全息原理,用计算机制作彩虹全 息图的H1,并用镜像折叠的新算法将大幅的全息图折叠成一幅较小的全息图。输出微缩后成为一个高密度的全息 图。光学方法制作H2时,必须配以合适的平面镜,使再现的光波按光的可逆原理展开成原状。该种镜像折叠的方 法巧妙地把计算机制全息与光学全息相结合,吸取了两者各自的优点,实现了大视角数字全息的制作。理论及实 验结果表明该方法既解决了大幅度计算机制全息图的输出问题,又使相同信息量的数据容量大大减少,为计算全 息图用于立体显示的研究开辟了一条新的途径。

A new technique of digital holography is proposed, which can make the holograms with large viewing angle. According to the theory of two-step rainbow holography, rainbow holograms H1 are generated by computer and the new algorithm of mirror image is proposed which can fold the holograms with large dimension into little ones. After the downsizing by taking pictures, a hologram with high density is made. When H2 is made on optical setup, two right mirrors must be matched in order to returning the reconstructed wave to the original condition. The advantages of both computer generated holograms and optical holograms are adopted in this technique. The technique of mirror image can successfully make the holograms with large viewing angle. The principle of the proposed method and the experimental result prove that the technique not only resolves the problem on the output of holograms with large dimension and reduces the data volume greatly, but also breaks a new path for hologram three-dimensional display.