Taming Light: Researchers Slow the Travel of Rays

Researchers have successfully trapped light in a confined area for a longer amount of time than ever before achieved, slowing the travel time of a single ray.

According to a study recently published in the journal Applied Physics Letters, physicists at the University of Rochester were able to confine light in a nanocavity for several nanoseconds - cutting the distance the light would have traveled in that time by several meters.

The cavity in question - a nanostructured region of a silicon wafer - is no bigger than one hundredth the width of a human hair, but served as a temporary "prison" far a ray of light for a longer time period of time than ever before achieved using nanocavities.

"Light holds the key to some of nature's deepest secrets, but it is very challenging to confine it in small spaces," study co-author Antonio Baolato said in a recent statement. "Light has no rest mass or charge that allow forces to act on it and trap it; it has to be done by carefully designing tiny mirrors that reflect light millions of times."

According to Baolato, the strategy taken to produce this latest light trap could potentially help nanophotoronic technology advance as a whole.

Traditionally, science celebrates light for its speed and absence of constraints, using it to send information with accuracy. Recently, NASA has started experimenting with laser based communication, hoping to use light beams to communicate with space-craft in real-time (or with a small relay delay) during deep-space missions.

However, trapping light can help researchers closer study its properties, allowing them to manipulate or couple it with other devices.

Nanophotonics circuits that rise from research like this could one day be integrated into technologies used in telecommunications or biosensing.

Also, "because they can process pulses of light extremely fast and with very low energy consumption, they hold the potential to replace conventional information-handling systems," the University of Rochester reports.

The study was published in the June issue of Applies Physics Letters.