16-01-2012, 02:25 PM
MULTI-SLM HOLOGRAPHIC DISPLAY SYSTEM WITH
PLANAR CONFIGURATION
[attachment=16101]
INTRODUCTION
-One way to enhance the 3D viewing comfort is to increase the hologram size (i.e. SLM size).
-Therefore, we propose and implement a multi-SLM holographic display system.
-The holographic display consists of six high-definition phase-only SLMs which are tiled in three by two fashion. After aligning them by using some optical elements and high precision stages we generate a large computer generated hologram.
-The generated large hologram is divided into six parts to match the SLM array. With the help of a video driver, the computed holograms are then loaded to the SLMs.
-We observed the reconstructions by illuminating the SLM matrix with a plane wave. Different from Ref.[10], we do not discard the vertical parallax; there are no lenticular sheets or any other optical elements. As a result of this experiment, we have shown that multiple SLMs can be used to increase field of view. With the help of the large field of view, observer can look at the reconstructions binocularly and see a ghost-like 3D image floating in the space.
-Since we use an LED as a light source, reconstructions can be observed by the naked eye.
HOLOGRAPHY
-Holography was invented in 1947 by Hungarian-British physicist DENNIS GABOR for which he received Nobel Prize in 1971
-Holography (from the greek “holo” whole+ “graphe” writing or drawing) is a technique that allows the light scattered from an object to be recorded and later reconstructed so that when an imaging system is placed in the reconstructed beam , an image of object will be seen even when the object is no longer present
SETUP AND HOLOGRAM GENERATION
-In our experiment, we have used six HoloEye HEO 1080P phaseonly spatial light modulators . Fig.5 (a) shows the top view of the setup.
-The light that emerges from the source, which is a LED, first passes through a spatial filter to increase the spatial coherence.
-After that with the help of a beam expander a plane wave is obtained.
-Then it is directed to the SLMs by mirrors, half mirrors and beam splitters.
-Phase holograms that are loaded to the SLMs are tiles of a large hologram which is calculated by a Fresnel based approach .
-Each SLM has 1920 × 1080 pixels and are tiled as a three by two matrix on a virtual planar surface (see Fig.5 (b)). Therefore the large hologram size is 5760×2160.
