Sunday, May 29, 2022

Engineers Create Brighter, Full-Color Holograms That Can Be Viewed With Low Light

Creating 'Star Wars' in reality.

A team of the University of Utah has developed the holographic chess game R2-D2 and Chewbacca played in “Star Wars” a reality. They have developed a way to create inexpensive full-color holograms that are far more realistic and brighter. Through this, scientists even showed 2D or 3D holograms at wider angles.

Generally, any projection image is inefficient because when white light shines on an object. Thus, we can only see the reflected color that bounces back to our eyes while the rest of the colors of the spectrum are absorbed. Thus, a large amount of light gets waste. But by using a typical LCD projector, only as little as 5% of the total light can be seen at one time.

Associate professor Rajesh Menon said, “You can have rich colors at high efficiency, with high brightness, and at low cost. And you don’t need fancy lasers and complicated optic.”

Scientists have discovered by applying the same principle behind how wings of certain butterflies display their colors. They redirected overall white light so that user can see the wavelengths of the wing’s colors at different locations. Thus, none of the light is absorbed and therefore wasted.

Engineers Create Brighter, Full-Color Holograms That Can Be Viewed With Low Light
University of Utah electrical and computer engineering associate professor Rajesh Menon. Menon leads a team of engineers who have discovered a way to create inexpensive full-color 2-D and 3-D holograms that are far more realistic, brighter and can be viewed at wider angles than current holograms. Credit: Dan Hixson/University of Utah College of Engineering

The study is published in Scientific Reports, named as ‘Full Color, Large Area, Transmissive Holograms Enabled by Multi-Level Diffractive Optics‘.

Menon said, “Projecting an image before was very inefficient, and you need a massive lamp. Here, you can just do it with just a piece of plastic and a flashlight. It’s much simpler and more efficient this way.”

According to scientists, it could be used on currency notes with security holograms that produce more lifelike images. Normally, holograms look like shimmering monochromatic images, but the full-color holograms created by this new technique look more like full-color photographs.

It also could be used for identification badges, driver’s licenses and security documents like passports. Officers can use a flashlight to recognize it instead of a special light such as an infrared scanner.

Scientists also noted, “These full-color holograms could be inexpensive to manufacture. Although, they can stamp out each sticker like a compact disc or DVD.”

Menon said, “Currently, we have produced 2-D still images. It wouldn’t be difficult to take the next step to create full-color 3-D moving images similar to the holographic chess pieces in Star Wars.”

“Imagine going through a ride and you want a monster to jump out. This is a way to do that with much richer color, with higher efficiency, and in a much more ubiquitous manner because it’s so cheap.”


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