A high-speed propulsion system for a high-speed vehicle includes an air intake duct, a compression section, a combustion section, and an expansion section. A gas dynamic laser generator is disposed proximate the expansion section and generates a source of laser light. A laser transmission mechanism receives the laser light and transmits the laser light from the gas dynamic laser generator to the combustion section and to presents the laser light into the air/fuel mixture of the flowpath which promotes mixing, combustion, and flame stability.

A controller of a laser ignition engine configured to perform ignition by using a laser ignition device configured to emit a laser beam condensed by a lens includes: a combustion state related value acquiring portion configured to acquire a combustion state related value related to a combustion state of the engine; and a contamination determining portion configured to compare the combustion state related value acquired by the combustion state related value acquiring portion with a combustion state determining value to determine whether or not the laser ignition device is contaminated, the combustion state determining value being defined based on the combustion state of the engine when the laser ignition device is not contaminated.