Holographic three-dimensional telepresence using large-area photorefractive polymer

Abstract

Holography is a technique that is used to display objects or scenes in three dimensions. Such three-dimensional (3D) images, or holograms, can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. The concept of 3D telepresence, a real-time dynamic hologram depicting a scene occurring in a different location, has attracted considerable public interest since it was depicted in the original Star Wars film in 1977. However, the lack of sufficient computational power to produce realistic computer-generated holograms and the absence of large-area and dynamically updatable holographic recording media have prevented realization of the concept. Here we use a holographic stereographic technique and a photorefractive polymer material as the recording medium to demonstrate a holographic display that can refresh images every two seconds. A 50 Hz nanosecond pulsed laser is used to write the holographic pixels. Multicoloured holographic 3D images are produced by using angular multiplexing, and the full parallax display employs spatial multiplexing. 3D telepresence is demonstrated by taking multiple images from one location and transmitting the information via Ethernet to another location where the hologram is printed with the quasi-real-time dynamic 3D display. Further improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment.

Advances in small lasers

“…1e) or on Au nanorods embedded in a dye loaded polymer matrix. The experiments looked at a large ensemble of many of these devices (>10 6 ). An experimental demonstration of a single isolated device has yet to be shown.…”

“…Continued miniaturization of lasers may also open new avenues in medical imaging and sensing if such lasers can be made biocompatible and implantable 4,5 . Likewise, 3D displays and advanced holography may benefit from considerably more compact coherent light sources 6 .…”

Molecular design of photorefractive polymers

“…122,123 By using a pulse laser with a duration time of 6 ns that delivered 200 mJ per pulse at a repetition rate of 50 Hz, 100 hogels were recorded for 2 s to reconstruct multicolor holograms on a 300 mm diameter PR device consisting of PATPD-CAAN/FDCST/ECZ/PCBM (49.5/30/20/0.5 by wt.). 124 The hologram had a brightness of 2500 cd m − 2 , reduced laser power of 20 mW CW laser, and reported an improvement in resolution and a three-color hologram. 125 Tsutsumi et al [126][127][128] at the Kyoto Institute of Technology, Japan, also demonstrated the development of an updatable 3D hologram and holographic stereogram images using a monolithic compound containing carbazole-azobenzene without a bias-field.…”

“…Peyghambarian's group at the University of Arizona, USA, demonstrated the development of updatable 3D holographic displays using a combination of a PR polymer device and a holographic stereogram technique. [122][123][124][125] They succeeded in developing a long-persistence updatable hologram system, which could be viewed for minutes to hours by controlling the T g of the PR polymer device. They recorded 100 hogels for 2-4 min using a holographic stereographic technique to reconstruct a monochromatic hologram, which could be observed for 3 h on a 100 mm × 100 mm PR device consisting of PATPD-CAAN/ FDCST/ECZ (50/30/20 by wt.).…”

Arrays of Lucius microprisms for directional allocation of light and autostereoscopic three-dimensional displays

“…Autostereoscopic 3D display. The ability of the Lucius prism array to directionally allocate the incident light intensity suggests its use in various optical devices [18][19][20][21][22][23][24][25][26] , such as dual-view or autostereoscopic 3D display [27][28][29][30][31] . To perceive a 3D image, human eyes must see different views (binocular disparity), allowing for the sensation of depth known as stereopsis after complicated processing in the brain 29 .…”