Using ‘transmission matrix,’ physicists devise way to see through opaque materials

Physicists have devised a way to see through paper, paint, biological tissue and other opaque materials.

The problem with these materials is that light scatters in complex ways when it passes through them.

But researchers at the City of Paris Industrial Physics and Chemistry Higher Educational Institution say it’s possible to focus light through opaque materials to detect objects hidden behind them.

In an experiment, the researchers first passed light through a layer of zinc oxide, used in both white paints and sunscreen.

The researchers studied the way the light beam changed as it encountered the material to produce a numerical model called a “transmission matrix.”

The matrix, which includes more than 65,000 numbers that describe how the zinc oxide layer affected the light, was then used to beam light with the specific intention of passing through the layer and focusing on the other side.

Similarly, the researchers found they could measure light emerging from the opaque material and translate it, so to speak, with the transmission matrix to discern the image behind the layer.

So what’s this all mean, exactly? The study’s results tell us that an opaque material can very well be a high quality optical element — so long as a sufficiently detailed transmission matrix is constructed.

That’s big news for nanoengineering, where transparent lenses are challenging to build at such a small scale.

Their results were published in the current issue of Physical Review Letters.