🌟 Steering light on the nanoscale: towards tiny optical circuits

Scientists have developed an ingenious method to create and control ultra-confined light waves, a significant step towards realizing tiny optical circuits.

This method works in two steps, like giving momentum to a swing. First, a very small gold antenna illuminated by light creates a basic wave on a special crystal (MoO3). Then, this wave reaches the sharp edge of the gold layer, where it bounces and gains extra energy. This "springboard" allows it to transform into an even more concentrated and powerful type of wave, which is difficult to obtain using conventional single-step methods.


Thanks to this technique, researchers have obtained waves of exceptional quality that can propagate very far without losing energy. This success is due to the efficiency of the method and the use of a crystal suspended in air, which reduces losses. These performances show great potential for future optical technologies, where miniaturization and efficiency are crucial.

The most notable aspect of this technique is a phenomenon called pseudo-birefringence. At the edge of the gold, the different types of light-matter waves are naturally separated and steered in different directions, while preserving their properties. It's like a train switch, but for light on the nanoscale.

This ability to sort and direct waves opens up concrete prospects for ultra-compact optical circuits. It could, for example, allow multiple data streams to be sent in parallel through the same tiny channel. Other applications are conceivable, such as innovative optical filters or extremely sensitive biological sensors integrated on a chip.

This research, published in the journal Nature Photonics, provides tools for manipulating light at a minute scale. It is part of the quest for ever smaller optical components, needed for fast information processing and precise chemical detection. This method opens horizons for future communications and information technologies.