Seven cores: a more even flow of light in an optical fibre

On 25 September, the Russian Science Foundation reported research by scientists at the Institute of Automation and Electrometry in Novosibirsk. The team studied how light exchanges energy between seven closely spaced cores inside an optical fibre.

The experiment used roughly ten metres of fibre. At low power, the output energy distribution fluctuated substantially. Pulses with peak power of several kilowatts produced more even sharing between the cores, with fluctuations below 5% under the conditions described by the authors.

A mathematical model linked the effect to nonlinear changes in the phase of light and averaging of energy exchange over each pulse. The combined output formed a stable beam instead of a patchy light pattern.

The study appears in Opto-Electronic Advances. Lasers, communications and optical sensing are potential applications. This is an experimental result; it does not establish that a finished technology has already been deployed in communications networks.