Introduction: Internal combustion engines play a dominant role in transportation and energy production. Even a slight improvement will translate into considerable reductions in pollutant emissions and impact on the environment. The two major types of internal combustion engines are the Otto and the Diesel engine. The former relies on an ignition source to start combustion, the latter works in auto ignition mode. An ignition system is a system for igniting a fuel-air mixture. Ignition systems are well known in the field of internal combustion engines such as those used in petrol (gasoline) engines used to power the majority of motor vehicles. The spark ignited Otto engine has a widespread use and has been subject to continuous, sophisticated …show more content…
• Ignition location cannot be chosen optimally. • Spark plug electrodes can disturb the gas flow within the combustion chamber. • It is not possible to ignite inside the fuel spray. • It requires frequent maintenance to remove carbon deposits. • Leaner mixtures cannot be burned, ratio between fuel and air has to be within the correct range. • Degradation of electrodes at high pressure and temperature. • Flame propagation is slow. • Multi point fuel ignition is not feasible. • Higher turbulence levels are required. • Erosion of spark plug electrodes. Laser: A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation". Laser provide intense and unidirectional ray of light. Laser light is monochromatic. Wavelength of light is determined by amount of energy released when electron drops to lower orbit. Light is coherent; all the photons have same wave fronts that launch to unison. Laser light has tight beam and is strong and concentrated. To make these three properties occur takes something called “Stimulated Emission”, in which photon emission is