Flip Flop to speed up communications

Researchers from the University of Rochester have created a device that has the potential to remove major blockages between optical networks.

The device, dubbed the flip flop switch and developed in conjunction with the University of Tokyo, is said to be so flexible that it can reformat the information that is shuttled around the information superhighway in ways and at speeds that no other device today can match.

If successful, the flip flop switch may find a niche in an Internet driven market that, in North America and Europe, will be worth approximately $15 billion in by 2004.

Engineers hope the device—smaller than a grain of sand—will allow fast optical data conversion that could spur the development of extensive local fibre-optic communications networks.

The tiny switch acts like a shade on a window, opening and closing in a billionth of a second, allowing an exact amount of light through at the right wavelength.

The switch consists of a laser and a microscopic piece of semiconductor, indium phosphide, which monitors pulses of light in a wide range of wavelengths.

When a pulse of light comes down an optical fibre and strikes the semiconductor, the material becomes transparent to the device’s laser. The laser, shining at another wavelength, shines through for a split second before the shade closes again, re-creating the original pulse of light in the new wavelength.

In under a billionth of a second, the pulse has been converted from one wavelength to another.

Converting a pulse’s wavelength so quickly is important where two fibre optic networks intersect, such as at the junction of local and long-distance telephone networks.

Long-distance communications companies may move voices in one wavelength, whilst a local phone company may use a different wavelength, necessitating a fast conversion.

Engineers have long been working to develop light-to-light wavelength-converting switches that do not require the electronics used today.

The new switch is also said to be exceptionally good at removing another hurdle that slows the junction of optical networks.

Different networks use different lengths of pulses; the new switch operates so quickly that it can customise the length of the pulses by simply varying the time before ‘shutting the shade.’

Leaving the shade open a little longer results in a longer pulse; shutting it sooner makes a shorter pulse, allowing any network to receive the exact pulse length it needs.