A duo of researchers from France and South Korea has developed a third-generation holographic printing system that produces 3D holograms with an unprecedented level of detail and realistic color, and solves the known problems of the two previous generations.
The new holoprinter, dubbed CHIMERA, creates holograms with wide fields of view and full parallax on an ultrafine-grain silver-halide material.
Full parallax holograms reconstruct an object so that it is viewable in all directions, in this case with a field of view spanning 120 degrees.
The printer can create holograms from 3D computer generated models or from scans acquired with a dedicated scanner.
“Our 15-year research project aimed to build a hologram printer with all the advantages of previous technologies while eliminating known drawbacks such as expensive lasers, slow printing speed, limited field of view and unsaturated colors,” said Yves Gentet, from Ultimate Holography.
“We accomplished this by creating the CHIMERA printer, which uses low-cost commercial lasers and high-speed printing to produce holograms with high-quality color that spans a large dynamic range.”
When developing the new printer, Yves Gentet and his colleague, Philippe Gentet of Kwangwoon University, studied two previously developed holographic printer technologies to understand their advantages and drawbacks.
“The companies involved in developing the first two generations of printers eventually faced technical limitations and closed,” Yves Gentet said.
“Our small, self-funded group found that it was key to develop a highly sensitive photomaterial with a very fine grain rather than use a commercially available rigid material like previous systems.”
The CHIMERA printer uses red, green and blue (RGB) low-power commercially available continuous wave lasers with shutters that adjust the exposure for each laser in a matter of milliseconds.
The team also created a special anti-vibrating mechanical system to keep the holographic plate from moving during the recording.
Holograms are created by recording small holographic elements known as hogels, one after another using three spatial light modulators and a custom designed full-color optical printing head that enables the 120-degree parallax.
After printing, the holograms are developed in chemical baths and sealed for protection.
The hogel size can be toggled between 250 and 500 microns and the printing rate adjusted from 1 to 50 hertz (Hz).
For example, if a hogel size of 250 microns is used, the maximum printing speed is 50 Hz. At this speed it would take 11 hours to print a hologram measuring 30 by 40 cm, about half of the time it would take using previous systems based on pulsed lasers.
“The new system offers a much wider field of view, higher resolution and noticeably better color rendition and dynamic range than previous systems,” Yves Gentet said.
“The full-color holographic material we developed provides improved brightness and clarity while the low-power, continuous wave lasers make the system easy to use.”
A paper describing the CHIMERA printer was published in the journal Applied Optics.
Yves Gentet & Philippe Gentet. 2019. CHIMERA, a new holoprinter technology combining low-power continuous lasers and fast printing. Applied Optics 58 (34): G226-G230; doi: 10.1364/AO.58.00G226
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