| 摘要 |
In a laser ignition apparatus, a focusing optical element is configured to focus a pulsed laser light to a predetermined focal point in a combustion chamber of an engine. An optical window member is arranged on the combustion chamber side of the focusing optical element so as to separate the focusing optical element from the combustion chamber. A catoptric-light focal point, at which a catoptric light is to be focused, is positioned on the anti-combustion chamber side of a combustion chamber-side end surface of the optical window member. The catoptric light results from the reflection of the pulsed laser light by a pseudo mirror that is formed by the optical window member when the combustion chamber-side end surface thereof is fouled with contaminants. Further, the catoptric-light focal point falls in a region where no solid material forming either the focusing optical element or the optical window member exists. |
