Laser Spark-Plug Development - From Experimental Device to Successful Engine Ignition

In this work a review of the research performed on laser ignition (LI) in internal combustion engines, especially of gasoline engines, will be presented. The path from the first demonstration of LI in an internal combustion engine to the first operation by LI of a 4-cylinder gasoline test engine and to the implementation of LI in a real automobile will be discussed. Steps taken toward developing a spark-plug-like LI system for automobile, stationary gas engines for energy cogeneration or for space applications will be described. Results on multi-point LI of methane-air mixtures in a static, constant-volume combustion chamber will be introduced, proving that multi-point LI can extend the limits of flammability. It is concluded that LI has reached a quite high degree of technical maturity and that the advantages of using LI technique versus ignition by an electrical spark plug were demonstrated.