All this is possible via solitons - self-reinforcing solitary waves that maintain their shape while travelling at constant speed.
Scientists have discovered that solitons can also exist in small millimeter-size optical resonators. The optical resonators are crystals shaped to form a resonator that can guide a soliton light pulse on an endless circular path.
When such a soliton light pulse circulates inside the resonator, a small fraction of it can be extracted every time the pulse completes one round-trip, said a new study.
The scientists analysed the extracted light pulses from the resonator and found them to be surprisingly short in duration - much shorter in fact than one millionth of one millionth of a second.
Due to the small size of the optical resonator, the time between two extracted pulses is extremely short and the pulse rate very high.
"The solitons can be used for low-noise microwave generation or in future space-based optical clocks, significantly improving today's geo-navigation," said the scientists working at Lausanne-based EPFL's Laboratory for Photonics and Quantum Measurement.
Soliton water waves can travel several kilometres without any significant change in their shape or amplitude, as opposed to normal waves, which widen as they travel, and eventually disappear.
Solitons can retain their shape because of non-linear and dispersive effects that stabilise the wave, said the study, published in Nature Photonics.
--IANS (Posted on 24-12-2013)