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Russian scientists 'catch light' with dielectric balls

MOSCOW, February 6. /TASS/ Researchers from L.V. Kirensky Institute of Physics at Siberian Branch of RAS (SB RAS) and M.F. Reshetnikov State Aerospace University (SAU) have come up with the idea to use a chain of identical dielectric balls as an electrowave "catcher", said the group of scientific communications at Krasnoyarsk Research Center from SB RAS (KRC SB RAS).

Such a chain will behave as an optical fiber which detects and grasps the light with an arbitrary descent angle. The results of calculations have been published in the journal Advanced Electromagnetics.

"The chain of identical balls of a diameter about a micron arranged as an ideal line will capture the light. Should one shine light onto the chain, the light will never quit it before we do not disrupt the chain or do not undertake some other manipulations as for instance heating," - commented Evgeny Bulgakov, Ph.D. in physical and mathematical sciences, leading research assistant at KRC SB RAS, Professor at SAU.

To transmit electricity, cables are utilized. In the particular case, the electromagnetic emission is blocked in a wire. The ionosphere of the Earth is used by humans to transmit radiosignals of long waves, while optical fibers, dielectric threads with optically transparent core and reflective envelope which blocks the light inside the thread, have been introduced for light transmission.

Light catcher

As a part of a project of Russian Research Foundation, Krasnoyarsk physicists study not only the transmission but also capture of light in open optical systems. To catch the light, the well-known phenomenon, the interference, is in use. The waves coming from opposite directions may enhance of quench each other depending on the match of peaks while meeting. In the case of the light wave, the main challenge by capturing is that one should first somehow split one wave and then make it coincide with its replica in the desired way in a predefined place in such a way that the wave could not quit the restricted place.

"We have come to the idea of a thread of dielectric balls which can capture and block the light. The light striking upon one ball is scattered in all directions. When a thread with two balls is applied, the part of the incoming light will travel between both of them but afterward will be scattered again. In our calculations, we have shown that a chain of hundred balls is already capable of catching the light," - said Almaz Sadreev, Dr. habil at physical and mathematical sciences, chief of Laboratory of Non-Linear Processes at KRC SB RAS.

Currently, similar effects are considered as a basis for future development of devices capturing waves of various length and nature. According to the scientists, one could in principle create catching devices for sound, electromagnetic, and quantum waves. After first publications on the topic "light capture" appeared several years ago, a lot of new investigations has been initiated.

The USA, China, and Korea are deemed as world leading countries in "light catching" business where the scientists are in progress of performing both computations and experiments on the topic. Russian researchers expect that very soon theory of light catchers will meet experiments also in Russia which brings new insights.