Laser spark plugs do sound pretty neat. In Japan, researchers at the National Institute of Natural Sciences have cooked up an exceptionally compact laser that's robust enough for automotive use. With lots of strong ceramics and two different yttrium-based laser elements, one doped with neodymium and the other chromium, the lasers are capable of being pulsed more quickly and more accurately than current spark plug technology allows. Another benefit of lasers in the combustion chamber is the ability to ignite the air/fuel mixture with more power than a spark plug can reliably dissipate.
Modern engine management systems and direct fuel injection are capable of exceptional efficiency and more complete combustion than ever before, and gasoline contains a lot more energy per pound than any current automotive battery technology. While spark plugs might seem antiquated, they're far cheaper than fitting lasers for ignition, and the ignition systems attached to those plugs continue to get more and more sophisticated.
None of this research work has been applied to an actual engine yet, making any claims of superiority mere academia at this point. The NINS work will be presented at the 2011 Conference on Lasers and Electro Optics that's happening in early May. While there's great potential for small lasers that can stand up to harsh environments, and the developers are working with suppliers and automakers, it's not likely that your engine will be lit off by an Nd/Cr:YAG any time soon, despite what the car-haters who skim over engineering facts might have to say.
[Source: Fast Company]