Development of three-dimensional display devices using color holography and its applications

1. 用狭缝记录的反射全息图有其独特的特点，即即使在离全息图较远的地方也能得到清晰的单色图像。重建图像的颜色在整个全息图上的变化取决于观察者的位置。利用CIE色度图分析了颜色的变化，发现在通常的观测条件下，颜色的变化很小，得到了清晰的彩色图像。这个结果已被实验证实了。利用全息图CAD工具进行全息光学元件的设计。利用全息图CAD工具对全息光学元件进行了优化设计。我们开发的工具是专门用于设计全息图的。以全息透镜为例，设计了不同波长的记录和重建全息透镜。在这种情况下，重构波含有像差。用计算机生成的全息图补偿像差，获得了衍射极限成像。实验验证了该CAD工具的有效性。本文还设计了用于光纤通信的波长解复用器，并通过简单的记录排列获得了效率高、像差小的解复用器。全息图在显示系统中的应用我们提出了一种平视显示系统，该系统利用曲面镜将液晶显示器的图像成像到全息屏幕上，作为所设计器件的应用。实验获得了距离全息图50cm处的清晰图像。我们有一个HOLD-FACTORY计划作为接下来的研究，其中全息图是通过信息网络设计和制作的。

1. Analysis of color reproduction of the reconstructed imageThe reflection hologram recorded by using a slit has unique features that the reconstructed image is sharp and mono-color even the image is disposed far apart the hologram. The color of the reconstructed image is changed across the hologram depends on the position of the observer. The change of the color was analyzed using CIE chromaticity diagram and we found that the change is quite small within the usual observation condition and sharp color image is obtained. The result has been confirmed by the experiment.2. Design of the holographic optical elements using the hologram CAD tool.Optimization of holographic optical elements by using the hologram CAD tool was demonstrated. The tool, which we have been developed, is specialized to design holograms. For an example a holographic lens, whose wavelengths are different in its recording and reconstruction, was designed. In this case, the reconstructed wave contains aberrations. The diffraction limited imaging is obtained by compensating the aberration with computer generated hologram. The experiments verified the validity of the CAD tool.We also designed the wavelength demultiplexer for optical fiber communication and showed that the demultiplexer with high efficient and small aberration is obtained with simple recording arrangement.3. Application of the hologram to display systemWe proposed the head up display system in which the image of the liquid crystal display is imaged on the holographic screen using the curved mirror as the application of the designed device. The sharp image reconstructed at 50cm apart from the hologram was obtained by the experiment.We have a plan of HOLD-FACTORY as the following study, in which the holograms are designed and fabricated through the information network.