A LASER that converts more than half the electrical energy supplied to it into light has been built by researchers at Sandia National Laboratories in New Mexico. It is the first laser to work this efficiently in the power range suitable for optical communication systems. Other high-efficiency lasers are hundreds of times more powerful, so they would overload fibre-optic systems and waste energy.
Kent Choquette, Kevin Lear and Richard Schneider at Sandia achieved the break-through by modifying the design of a vertical-cavity semiconductor laser. The lasers commonly used in low-power optical communications are of the horizontal-cavity type, and typically convert only 20 to 30 per cent of electricity into light. Higher efficiency is important because energy that does not end up as light ends up as heat, and heat dissipation can be a limiting factor for some electronic and optical devices.
Semiconductor lasers are built on flat, layered chips. They ...
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