A laser device that enabled today's Internet is now being exploited in a range of applications from imaging molecules to high-precision cutting of metals. In the mid-1980s research at Southampton University, provided a simple solution to the problem of signal attenuation as information travels as light along optical fibres.
‘Previously electronic devices were needed at various points along a fibre cable to boost the optical signal,’ says David Richardson of the Optoelectronics Research Centre, University of Southampton. ‘Converting the data from an optical signal to an electronic signal and back again created a bottleneck. We developed an all-optical amplifier based on optical fibres that eliminated optoelectronic signal conversion allowing far greater amounts of data to be sent over much longer distances.’
The amplifiers originally designed for telecommunications are now being exploited in a vast range of other applications. ‘Through relatively simple changes to the fibre structure we’ve been able to increase power levels by 100,000 to the kilowatt regime – sufficient to cut through steel plate,’ says David. Another feature of fibre amplifiers is the high beam quality, which allows precise focusing of the laser light. The precision cutting of metals this enables has applications in manufacture of coronary stents that maintain damaged arteries in heart patients.