Ordinary light scatters in all directions, like water from a shattered glass. But in some crystals, light waves can bunch together into narrow beams and flow in a single direction, like water in a trough. Physicists studied such a material: layered vanadium oxide α-V2O5.
In this crystal, atoms vibrate differently along and across the layers. As a result, light entering the crystal behaves unusually: waves traveling in different directions cancel each other out, leaving only one beam. It resembles a thin jet that doesn't spread. The researchers captured these beams using an ultra-high-resolution infrared microscope.
This property is called polariton canalization. A polariton is a hybrid of a light wave and atomic vibrations. In α-V2O5, these mixed waves spontaneously form channels without any additional material processing. Previously, this required complex devices or modifying the crystal itself.
Such light behavior promises new possibilities for nano-optics: light can be controlled at scales hundreds of times smaller than the thickness of a human hair. The beams do not scatter and follow a precise path, like rails for light.
The thickness of a light beam in this crystal is about 50 nanometers, a thousand times thinner than a human hair.
In 'Star Trek,' light beams are used for transmitting energy and information; similar directed light flows in crystals are a step toward such technologies.