Economic as well as environmental constraints demand a further reduction in the fuel consumption and the exhaust emissions of motor vehicles. At the moment, direct Injected fuel engines show the highest potential in reducing fuel consumption and exhaust emissions. Unfortunately, conventional spark plug ignition shows a major disadvantage with modern spray-guided combustion processes since the ignition location cannot be chosen optimally. It is important that the spark plug electrodes are not hit by the injected fuel because otherwise severe damage will occur. Additionally, the spark plug electrodes can influence the gas flow inside the combustion chamber.
It is well know that short and intensive laser pulses are able to produce an â€optical breakdownâ€ in air. Necessary intensities are in the range between 1010- 1011W/cm2.1, 2 at such intensities, gas molecules are dissociated and ionized Within the vicinity of the focal spot of a laser beam and a hot plasma is generated. This Plasma is heated by the incoming laser beam and a strong shock wave occurs. The expanding hot plasma can be used for the ignition of fuel-gas mixtures.