Lasers could replace spark plugs in gasoline engines

BBC : For 150 years, spark plugs have ignited the mixture of gasoline and air that fuels car engines. Now, as Jason Palmer of the BBC reports, lasers could supplant the venerable spark plug. Despite their longevity and simplicity, spark plugs are not without problems. They degrade over time in the harsh environment of an engine cylinder and they ignite only a small, single volume of gas–air mixture; less localized ignition would be more efficient. By contrast, lasers can be focused to ignite the gas–air mixture at several sites throughout the cylinder. But to have any chance of being incorporated into a commercial engine, laser spark plugs must be compact and robust. To meet that challenge, a team from Romania and Japan has developed ceramic lasers that can fit inside a cylinder. Energy is delivered to the lasers via fiber optic cable from lasers that are positioned outside the engine.