Scientists develop alternative to X-rays

Wed, Sep 22 06:09 PM
Doctors may soon be able to see a patient's innards in normal light without X-rays, as French scientists claim to have found a new way to decipher the little light that passes through opaque materials.

When light passes through materials that we consider opaque, such as paint, biological tissue, fabric and paper, it is scattered in such a complex way that an image does not come through.

But, now physicist Sylvain Gigan and his colleagues at the Industrial Physics and Chemistry Higher Educational Institution in Paris said they have that found they can actually reconstruct complex images from light passing through these barriers.

The key, they said, is to know precisely how the barriers interfere with this light, the LiveScience reported.

For their research, Gigan and his team first shone a green laser beam at a layer of zinc oxide -- a common ingredient in white paints -- that was roughly 80 microns thick, or slightly thinner than a human hair.

By analysing the pattern of light that passed through, the researchers generated a formula called a "transmission matrix" that made sense of the seemingly random way the light was scattered by the barrier.

With this knowledge, they were able to reconstruct a 32-pixel by 32-pixel image of a five-petal flower projected onto the zinc oxide.

However, the researchers said the see-through vision was not perfect as a lot of the information needed to reconstruct images gets lost when the light gets scattered, making the images look grainy.

It also won't find use in trying to look through walls, unless they are very thin indeed -- looking through a 100-millimeter wall would prove a million times harder than looking through a wall 100 microns thick.

Still, their method could one day be used to peer inside bodies, Gigan said.

That would require their system to be roughly 1,000 times faster than it currently is, to make up for all the scattering generated by the movements of living tissue.

"A microelectromechanical array that uses tiny mirrors to quickly divert laser beams back and forth over a surface to scan it should provide for the 1,000 times speed increase we are looking for," Gigan said.

The new findings are published online in the journal Nature Communications.

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