Single optical pulse electronics have potential for communications, sensors and navigation

Solitons are a special kind of wave. First noticed in water in the 19th century, they are a single pulse that moves at a constant velocity without losing its shape. They also occur in light, and researchers at Purdue University in Indiana are investigating their generation and use.

One barrier to the use of solitons has been an inability to harness them within devices small enough to fit onto a microchip. The Purdue team has devised a method which uses rings of silicon nitride with a radius of around 100 µm. Known as microrings, these are compatible with silicon electronics and act as a device called a microresonator (a structure that can store moving light waves), and the team claims in the journal Optica that this has allowed them for the first time to generate single stable solitons without the need for any active control of the system to tune it.