Paper
25 January 2008 Horizontal resolution enhanced hologram to increase horizontal viewing angle
Author Affiliations +
Abstract
We propose a new technique to increase the horizontal viewing angle of a hologram. The narrow viewing angle is one of the main problems of the conventional holography. The proposed technique enables to increase the viewing angle without decreasing the pixel pitch of a SLM. Multiple point light sources arranged on a slant line illuminate a SLM through a condenser lens. A 4f imaging system is used to image the SLM onto the screen. On the Fourier plane of the 4f imaging system, multiple Fourier-transformed images appear on a slant line. A horizontal slit is used to extract a horizontal rectangular area on the Fourier plane. With this method, the width of the Fourier-transformed image becomes K times longer and the height becomes 1/K times shorter, when the number of light sources is K and the light sources and the slit are prepared appropriately. Thus the horizontal resolution on the screen becomes K times larger, and the vertical resolution becomes 1/K times smaller. Consequently, the horizontal viewing angle of a hologram displayed on the screen increases ~K times. We experimentally verified the proposed method. The LCOS with the pixel pitch of 9.5 μm and the resolution of 4,096×2,160 was used as a SLM. The light emitted from a laser diode having the wavelength of 0.635 μm was enlarged to illuminate four micro lenses to generate four point light sources (K = 4). We found that the horizontal viewing angle was enlarged to ~15°. The three-dimensional images could be observed by both eyes.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yuki Hayashi and Yasuhiro Takaki "Horizontal resolution enhanced hologram to increase horizontal viewing angle", Proc. SPIE 6912, Practical Holography XXII: Materials and Applications, 69120I (25 January 2008); https://doi.org/10.1117/12.761576
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Cited by 1 scholarly publication.
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KEYWORDS
Spatial light modulators

Holograms

Light sources

Imaging systems

3D image reconstruction

Image resolution

Fourier transforms

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