数字全息多平面成像技术研究

提出了一种新的数字全息多平面成像技术:将非共轭二次扭曲位相因子作用于实验记录的数字全息图,只需一次菲涅尔衍射便可同时对多个成像平面进行重建。首先介绍了非共轭二次扭曲位相因子多平面成像原理,然后开展实验验证了方法有效性。此方法只需记录一幅处于多个不同平面物体的数字全息图,依据该理论选择合适参数,可在任意位置重建多个平面再现像。采用均方根误差(RMSE)与峰值信噪比(PSNR)作为图像质量评价标准,比较了不同再现距离的成像质量。文中提出方法在无需对光路进行对称设计的前提下,可同时对多个平面进行数字聚焦,延拓了菲涅尔数字全息重建图像的焦深。

Multi-plane imaging in digital holography

A novel method for multi-plane imaging in digital holography was proposed. A non-conjugated quadratic distorted phase factor was used to act on the experimental recorded digital hologram and the reconstructed images at multiple planes would be obtained simultaneously by only single Fresnel diffraction. It was firstly introduced the principles for multi-plane imaging using non-conjugated quadratic distorted phase factor and the effectiveness of the proposed method was verified by experiments. It needed single digital hologram of objects at different positions and multi-plane images could be rebuilt at arbitrary reconstruction distance by selecting the suitable parameters according to this paper's theory. The root mean square error(RMSE) and peak signal to noise ratio(PSNR) were used for evaluation standard of the image quality and reconstructed images at different positions were compared. Digital focusing at multi-planes can be achieved simultaneously without the symmetric optical design on the premise and the depth of focus for the Fresnel digital holographic reconstruction images can be extended.