Image design for normal viewing image-plane disk-type multiplex hologram

Abstract

In this letter, the method of direct object-image relationship in normal-view disk-type multiplex holography is adopted for theoretical analysis. The corresponding parameters in hologram fabrication and reconstruction process for both virtual-image and real-image generation are also introduced through numerical simulation and experimental results.OCIS codes: 090. 0090, 090.4220, 090.2870. doi: 10.3788/COL201109.120003. Since the concept of wavefront reconstruction was first presented by Gabor [1] , the holographic technology has become one of the most important branches of optics. In 1962, Denisyuk developed a new type of hologram called reflection hologram [2] . The reconstructed image ray generated from a reflection hologram is monochromatic due to its distinguishing feature of high wavelength selectivity, making it suitable for full-color image display [3,4] . Rainbow hologram, the reconstructed images of which can be demonstrated under white-light illumination, was proposed by Benton in 1969 [5] . Recently, multiplex hologram [6,7] proposed by DeBitetto has been applied into several formats, including planar-type, cylindricaltype [8] , conical-type [9] , and disk-type [10] holograms. Conventional multiplex holograms are composed of a series of long thin individual holograms, which inevitably cause the reconstructed images overlaid with a fence structure [10] . To eliminate the fence structure overlaid on the reconstructed image generated from conventional multiplex hologram, the image-plane method is utilized. The image-plane method has been designed for various formats of holograms, including cylindrical-type, conicaltype, and disk-type holograms [11−13] . Due to the lower diffraction efficiency of multiple-exposure holograms, the two-step recording technique was developed to overcome this limitation [14,15] . Reflection holograms have been widely used for display; thus, we developed reflection image-plane disk-type multiplex hologram (IPDTMH) through both one-step and two-step recordings [16,17] . The disk-type multiplex hologram has the advantage of commercial mass production owing to the utilization of the well-developed CD technology. Recently, we developed a 360-degree-viewable IPDTMH by one-step recording [18] . In the current letter, we describe how to make a normal-view IPDTMH using a one-step process. The 3D-display conditions for virtual-image and realimage generation are discussed. Suitable parameters for holographic recording are obtained by numerical analysis, and experimental results are also demonstrated.The holographic processes for making an IPDTMH are introduced by Figs. 1 and 2. Figure 1 shows our optical system for IPDTMH fabrication by one-step recording while Fig. 2 shows the reconstruction condition for a transmission-type IPDTMH. In the hologram fabrication process, the recording film is illuminated by a normalincidence object beam W O and a reference beam W C . On the holographic film plane, a series of image-plane holograms is recorded. For viewers at the observation plane dur...

Real-Image Generation in Normal Viewing Disk-Type Multiplex Holography and Design of Replication Method

“…In the application for commercial mass production, this kind of hologram is a suitable candidate with the aid of optical copying technique. 15,20) We here utilize the method of twostep recording, which are the fabrication of master hologram H 1 and the formation of transfer hologram H 2 , for one-shot holographic replication. The optical system described in Fig.…”

“…By shifting the rotational axis of the recording film and also reversing the holographic recording sequence, this kind of hologram can be made to generate real image. [15][16][17] Referring to Fig. 2(a), holographic information of a developed IPDTMH then becomes from the upper half of the disk for 3D-image display.…”

“…Based on the model of holographic recording and reconstruction, we can theoretically obtain suitable conditions for fabricating this kind of hologram. 15) To decide a suitable key parameter N h ¼ AE h =2 0 (hologram number), we have to optimize and choose the designated viewing distance d fe for observers. 14) In this study, we selected our experimental parameters for the observation condition which corresponds to d fe ¼ 0:8 m. Figure 2(b) shows a schematic diagram for 2D-image capture while Fig.…”

“…15). 15) Table I also shows the relationship among all parameters depicted in Figs. 1, 2, and 5 for the fabrication and the reconstruction processes.…”

“…In 2003, image-plane disk-type multiplex hologram (IPDTMH) for normal viewing was proposed to overcome the problem of picket-fence effect. 14,15) Recently, we developed a 360 viewable IPDTMH which can be viewed by the surrounding observers simultaneously. 16,17) To overcome the problem of lower diffraction efficiency of multiple-exposure holograms, one may adopt holographic copying to obtain duplicated hologram with higher optical performance.…”