提出一种基于一维光栅函数进行纯相位编码的方法,该方法以双相位全息编码技术为基础,将复振幅图像编码成纯相位图,并将编码得到的相位图直接加载到相位型空间光调制器上进行光学重建。在重建过程中,用一个有低通滤波器的4-f系统选择衍射级次,并选用一级衍射分量进行重建。一维光栅函数编码可以提高一级衍射分量所能获得的能量。因为没有相位元件零级信息的影响,重建图像的质量得到了提升。数值模拟和实验结果证明,该方法可以有效重构编码复杂物体的振幅和相位,该方法得到的一级衍射能量比二维棋盘格函数编码得到的一级衍射能量高。

A phase-only encoding method based on one-dimensional grating function is proposed. Based on double-phase hologram encoding technique, the complex amplitude image is encoded into a phase-only image, and then the image is directly loaded into the spatial light modulator for image reconstruction. During the optical reconstruction, a 4-f system with a low pass filter is used to select the diffraction order, and the first order diffraction component is chosen for reconstruction. The one-dimensional grating encoding function can improve the energy of the first order diffraction component. The quality of the reconstructed images is increased because there is no interference from zero-order information of the phase element. The numerical and experimental results show that the encoded amplitude and phase of the complex object can be reconstructed effectively, and the power of the first order diffraction got from the proposed method is higher than that of two-dimensional checkboard encoding function.