A group of scientists at Northwestern University has developed a new holographic camera capable of seeing behind obstacles to human sight. This device overcomes material objects or means of dispersion, such as skin, fog and even the human skull according to a publication in the journal Nature.
The device works by a method called synthetic wavelength holography which allows to capture the scattering of light behind hidden objects. According to the science news portal LiveScience, “holography is a photographic technique that records the light scattered by an object and then presents it in a way that appears three-dimensional.”
The camera runs an algorithm that reconstructs light scattering and can reveal such surprising objects as a moving heart or cars behind corners. According to Florian Willomitzer, lead author of the research, seeing around the corner and obtaining images of an organ within a body are similar phenomena.
“If you’ve ever tried to shine a flashlight through your hand, then you’ve experienced light scattering,” Willomitzer said.
“You see a bright spot on the other side of your hand, but theoretically there should be a shadow cast by your bones that reveals their structure. Instead, the light that passes through the bones is scattered within the tissue in all directions, completely erasing the image of the shadow, ”he said.
However, the biggest obstacle was having extremely fast detectors that allow light to be intercepted. For that reason, Willomitzer and his colleagues fused light waves from two lasers to generate a synthetic signal that can be adapted to holographic images in different scattering scenarios.
“If you can capture the entire light field of an object in a hologram, then you can reconstruct the entire three-dimensional shape of the object,” Willomitzer explained.
Over the years, there have been many attempts to retrieve images of hidden objects, but the drawbacks had been low resolution, tight angles, among others. However, according to the study authors, the new technology overcomes all of these problems.
While the method has obvious potential for non-invasive medical examination, car navigation systems, and inspection in tight spaces, the researchers believe the potential applications are endless.
With information from Europa Press.