The new technology allows cameras to capture colors invisible to the human eye

New research from Tel Aviv University will allow cameras to recognize colors that the human eye and even ordinary cameras cannot perceive.

The technology makes it possible to visualize gases and substances such as hydrogen, carbon and sodium, all of which have a unique color in the infrared spectrum, as well as biological compounds that occur naturally but are ‘invisible’ to the naked eye or ordinary cameras. It has innovative applications in a variety of fields from computer games and photography as well as the disciplines of security, medicine and astronomy.

The research was conducted by Dr. Michael Mrejen, Yoni Erlich, Dr. Assaf Levanon and Prof. Haim Suchowski of the TAU Condensed Material Physics Department. The study results were published in the October 2020 issue of Reviews of lasers and photonics.

“The human eye detects photons at wavelengths between 400 nanometers and 700 nanometers, between the blue and red wavelengths,” explains Dr. Mrejen. “But this is only a small part of the electromagnetic spectrum, which also includes radio waves, microwaves, X-rays and more. Below 400 nanometers there is ultraviolet or UV radiation, and above 700 nanometers there is infrared radiation. which in turn is divided into near, medium and far infrared.

“In each of these parts of the electromagnetic spectrum, there is a great deal of information about ‘color-coded’ materials that have until now been hidden from view.”

The researchers explain that colors in these parts of the spectrum are of great importance, as many materials have a unique signature expressed as a color, especially in the mid-infrared range. For example, cancer cells could be easily detected as they have a higher concentration of molecules of a certain type.

Current infrared sensing technologies are expensive and are mostly unable to reproduce those “colors”. In medical imaging, experiments have been performed in which infrared images are converted into visible light to identify cancer cells from molecules. To date, this conversion required very sophisticated and expensive cameras, which were not necessarily accessible for general use.

But in their study, the TAU researchers were able to develop a cost-effective and efficient technology that could be mounted on a standard camera and that allows, for the first time, the conversion of photons of light from the entire mid-infrared region to the visible region, at frequencies. that the human eye and standard camera can pick up.

“We humans can see between red and blue. If we could see in the infrared realm, we would see that elements such as hydrogen, carbon and sodium have a unique color,” explains the prof. Suchowski. “So an environmental monitoring satellite could ‘see’ a pollutant emitted from a plant, or a spy satellite would see where explosives or uranium are hidden. Also, since every object emits infrared heat, all this information could be seen even at night. . “

After filing a patent for their invention, the researchers are developing the technology through a grant from the Innovation Authority’s KAMIN project and have already met with a number of Israeli and international companies.