Scientists of the National Research University of Information Technologies, Mechanics and Optics, A.F. Ioffe Physics and Technology Institute and the Australian National University have found an easy way of calculating microscopic particles in optical materials by means of a laser. When passing through such substance a laser beam is diffracted and reflected as a pattern of bright spots on a projection screen. Experts have established that the  number of these spots corresponds to the quantity of disseminating microscopic particles in the material.
The new method enables scientists to visually estimate the structure and form of optical materials without the use of expensive electronic or nuclear power microscopy – thus, it makes the process of engineering optical devices much faster.

The research has been published in the Scientific Reports magazine.

"Light senses heterogeneity. Depending on relative positioning and the shape of lenses the wave extends on the other side of the sample in a particular way. In other words, the structure and size of a sample influence the diffraction picture which will be created by light, having reached the projection screen. We found out that, looking at this picture, it is possible to define the number of lenses in the material. It enables us to find out not only the type of a sample lattice (square, triangular and so on), but also to establish its structure (20 by 20 particles or 30 by 15) simply by counting light specks on the screen", – Mikhail Rybin explained. He is the original author of the article, the senior research associate of the Nanophotonics and Metamaterials Department of the ITMO University and Spectroscopy Laboratory of the Ioffe PhTI.

Making optical chip requires devices, which are capable of strengthening an optical signal, focusing it on detectors, and turning or changing the nature of its movement. Usual lenses cannot cope with this task in nanoscales any more, therefore scientists are developing the thinnest lenses from artificial optical materials, such as photon crystals and metamaterials. They make it possible to operate a light wave in a most unusual way. However receiving optical materials with necessary properties is a labor-intensive process that needs continuous improvement.

The new method is a much more affordable alternative to expensive electronic and nuclear power microscopy; at the same time it does not destroy samples and does not change their properties.