Gyu Chae Byung
Opt Express. 2023 Nov 6;31(23):37900-37910. doi: 10.1364/OE.503186.
The expansion of viewing angle is a crucial factor in holographic displays implemented with a spatial light modulator having a finite space-bandwidth. A holographic image is reconstructed at a viewing angle dependent on the numerical aperture of digital hologram. However, an interference of high-order noises is inevitable at an angle larger than the diffraction angle by a hologram pixel. This study presents the theoretical foundation for optimizing the Fresnel hologram to recover the low space-bandwidth. The higher spectrum components of the digital hologram beyond the bandwidth exists in the form of their replications. The expansion of angular spectrum by its repetition during optimization procedure increases the image resolution, resulting in a viewing angle that is determined by the hologram numerical aperture. We numerically and experimentally verify our strategy to expand a viewing angle of holographic image.
视角扩展是在使用具有有限空间带宽的空间光调制器实现的全息显示中的一个关键因素。全息图像是在取决于数字全息图数值孔径的视角下重建的。然而，在大于全息图像素衍射角的角度处，高阶噪声的干扰是不可避免的。本研究提出了优化菲涅耳全息图以恢复低空间带宽的理论基础。超出带宽的数字全息图的高频谱分量以其复制形式存在。在优化过程中通过其重复进行角谱扩展会提高图像分辨率，从而产生由全息图数值孔径决定的视角。我们通过数值和实验验证了我们扩展全息图像视角的策略。
