Single light wave flashes out from fibre laser

The Konstanz researchers started with pulses from a single fibre laser and split them between two sets of fibres that contained atoms of the rare earth metal erbium to amplify the light waves. Each fibre then had a second stage that altered the light’s wavelength, one stretching it by about 40 per cent, the other shrinking it by a similar amount. The two fibres then converged again, causing the two light beams to interfere with one another in a way that cancelled out most of the waves to leave just a single wave cycle lasting just 4.3 femtoseconds.

Magnetic Fields in Chaos

The magnetic fields generated by electric currents in wires are typically depicted as neat closed loops, but this may be more the exception than the rule. Computer-based calculations in the December Physical Review E show that magnetic field lines around simple wire configurations are tangled up like a ball of yarn. After accounting for the earth’s magnetic field, the researchers conclude that these chaotic magnetic fields are ubiquitous in the circuits found in all modern electronic devices.