Meaning from chaos

Nov 21, 2005

Transmitting light-based signals by embedding them in chaos doesn't sound like a particularly good idea. But in last week's issue of Nature, Claudio Mirasso and co-workers show otherwise. They have demonstrated that it is possible to send such a signal over a distance of 120 km using a commercial fibre-optic telecommunication network in the metropolitan area of Athens, Greece.

There are several benefits of sending information encoded in chaotic signals. For one thing, the chaos serves as a good encryption system: at face value, the signal looks like pure noise, and it's only when the receiver generates its own chaotic output signal, which can be synchronized with that of the transmitter, that the chaos can be removed to recover the true signal. But also, chaotic 'carrier' signals are broadband signals — they have a wide range of frequencies — which makes them more robust in the face of interference.

The basic idea is that a chaotic light signal is generated by a transmitting laser, and the receiver contains a second laser that can be induced by a feedback circuit to produce a chaotic output synchronized with that of the transmitter. The information-laden optical signal is mixed in with the chaotic signal in the transmitter, but can be decoded by subtracting the synchronized chaos of the receiver.

This process had been demonstrated previously over very short distances in the laboratory, but Mirasso and colleagues have now proved that it will work in the real world. A related News & Views article by Rajarshi Roy accompanies this research.

Source: Nature

Explore further: Physicists design quantum switches which can be activated by single photons

add to favorites email to friend print save as pdf

Related Stories

New method speeds up stabilisation of chaotic systems

Sep 30, 2013

(Phys.org) —When chaos threatens, speed is essential; for example, when a pacemaker needs to stabilise an irregular heartbeat or a robot has to react to the information received from its environment. Both ...

Complex activity patterns emerge from simple underlying laws

Jun 28, 2013

A new study from researchers at Uppsala University and University of Havana uses mathematic modeling and experiments on ants to show that a group is capable of developing flexible resource management strategies and characteristic ...

Chaos proves superior to order

May 07, 2013

An international team of physicists, including researchers from the Universities of York and St. Andrews, has demonstrated that chaos can beat order - at least as far as light storage is concerned.

Recommended for you

Could 'Jedi Putter' be the force golfers need?

Apr 18, 2014

Putting is arguably the most important skill in golf; in fact, it's been described as a game within a game. Now a team of Rice engineering students has devised a training putter that offers golfers audio, ...

User comments : 0

More news stories

Finnish inventor rethinks design of the axe

(Phys.org) —Finnish inventor Heikki Kärnä is the man behind the Vipukirves Leveraxe, which is a precision tool for splitting firewood. He designed the tool to make the job easier and more efficient, with ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.