A new patent shows that Mazda is working to replace your spark plugs with lasers.
In a patent filed with the World Intellectual Property Organization Mazda shows a control device that is supposed to manage laser-ignition. The purpose of the control device is to make on the fly adjustments to laser strength and air/fuel mixtures.
It's believed that lasers will allow Mazda to up compression ratios without increasing the voltage needed to combust. The higher voltage needed for higher compressions can wear out spark plugs faster then typical.
It's likely we see the technology first applied to the SkyActiv family.