| Summary: | 碩士 === 國立中央大學 === 光電科學與工程學系 === 101 === Multiplex holography has been developed for more than forty years. The advantage of Multiplex holography is that the subjects for holographic recording are not limited to be those which could be placed on the optical table. One can observe the reconstructed image of the original object from different directions if the multiplex hologram is made to be axially symmetric.
The conical holographic stereogram was developed in 1989 by Japanese research team led by K. Okada. The displaying type of this kind of hologram belongs to the transmission type. They recorded 2D image information belonging to different angles of the original object in a sequence of long, thin and fan-shaped areas of the recording film. Therefore, the reconstructed image will have many black stripes. It looks like viewing an image through a fence, called the “picket-fence effect”. This problem can be amended by using the image-plane technique.
In this study, we focus on this image-plane concept and design the method to record reflection image-plane conic multiplex hologram in one step. We add cylindrical lenses in both the object beam and the reference beam to compensate for the “astigmatic effect”, produced when hologram is curve into a conical surface. As a result, observer can watch wider range of the single hologram than before. We obtain 3D image with smaller deformation after this compensation process which increases the correcting freedom of “astigmatic effect” by utilization of an extra cylindrical lens in the object beam. The observer can perceive the 3D virtue image generated inside the hologram cone during reconstruction. We use computer to simulate the holographic process and the reconstructed 3D images observed at different positions. Using this fabrication method, we success fully recorded reflection image-plane conic multiplex hologram in one step and reconstructed 3D image with smaller deformation. The disadvantage of this method is the extremely narrow vertical viewing window and the lower diffraction efficiency. Finally, we propose some improved methods and the possible future development.
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