Opticians Take Part in Breakthrough Photon Experiment
(From left to right:) Petr Marek, Radim Filip, and Akira Furusawa in the laboratory of Tokyo University
Experts from the Department of Optics at the Faculty of Science, in collaboration with their colleagues from the University of Tokyo, made a significant step towards the recognition of the quantum properties of the photon, one of the elementary particles. With the help of a special technology developed by the Japanese partners, they were able, for the first time ever, to compress a single photon. The procedure for the experiment was developed in Olomouc. The results of the experiment were published in the journal Physical Review Letters in the United States.
A photon may be described, for the sake of simplification, as a packet of light energy. It carries both electric and magnetic energy. These continuous properties may be used independently, and this is what happens during the compressing operation. It does not involve, however, spatial compression of a light ray, known from classical physics; this operation increases the electric component and decreases the magnetic one.
Experiment conducted in Japan according to Czech instructions
“The experiment was made by our colleagues in Japan, since they are the only ones who possess the required technology of such quality. For the first time ever, compression was applied to a single photon. Such a manipulation at the level of individual microparticles is essential for future applications based on quantum information,” said one of the architects of the theoretical procedure, Petr Marek from the Department of Optics.
He prepared the blueprint for this procedure with Radim Filip in 2005. The experiment was conducted according to their plans, yet it did not involve a single particle. “The proposal allows performing a relatively large scale of quantum operations by means of measuring the irregular movement of light’s electrical energy. The trick is that the measurement data will be used for extremely fast modulation of the electrical intensity of a single photon,” explained Filip.
Photon is compressed, but not damaged
As a result, the experiment has confirmed the fact that it is possible to compress a photon. It had been presumed, but the scientists did not know how to perform this operation. The experiment has also shown that the operation is subtle enough, without any damage on the photon. “This is a very significant experiment in a number of areas, investigated by our team over a long period, from the search of the dividing line between classical and quantum physics, to practical quantum convertors between light and matter,” added Marek.
According to him, the experiment contributed to the understanding of the continuous properties of a single photon. Without the long-term cooperation with the university in Japan, however, the procedure would exist on paper only for some time. “The collaboration with the University of Tokyo has been very good in this. They concentrate intellectual and laboratory capacities with one ultimate goal – to improve our understanding of the possibilities of how to handle the world of nature in a meaningful way,” concluded Filip.
