Laser system and ignition device for an internal combustion engine

#The present invention relates to a laser system for an ignition device of an internal combustion engine, in particular of a motor vehicle, having a first laser device and a second laser device situated downstream from the first laser device and optically connected to it, the first laser device being designed for generating pump light for optically pumping the second laser device.

#A conventional laser system is depicted schematically in FIG. 1. Conventional laser system 100′ has a laser device 110 designed as a semiconductor-diode laser which generates pump light 10. Pump light 10 is transferred via a fiber optic device 130 to second laser device 120 which is normally situated directly in a laser spark plug 200.

#Second laser device 120 pumped by pump light 10 may be in particular a Q-switched laser device which generates high-energy laser pulses 20 for the laser ignition of an air-fuel mixture.

#FIG. 1 shows a conventional laser system.

#FIG. 2 shows a specific example embodiment of the laser system according to the present invention.

#FIG. 2 shows a specific embodiment of laser system 100 according to the present invention for an ignition device of an internal combustion engine. Laser system 100 has a first laser device 110, which in the present case is designed as a semiconductor-diode laser and is used for generating pump light 10 for optically pumping a second laser device 120. Pump light 10 is supplied to second laser device 120 via a fiber optic device 130 as shown in FIG. 2.

#Second laser device 120 may be, for example, a solid-state laser having a passive Q-switch (not shown), with the aid of which high-energy laser pulses 20 may be generated in a conventional manner. These high-energy laser pulses 20 are used for igniting an ignitable air-fuel mixture situated in a combustion chamber of the internal combustion engine. As shown in FIG. 2, solid-state laser 120 is integrated directly into a laser spark plug 200 of the internal combustion engine.

#Laser system 100 according to the present invention insofar corresponds to conventional system 100′ according to FIG. 1. According to an example embodiment the present invention, first laser device 110, which is also denoted below as pump laser, has a reflective arrangement 115 which are designed for reflecting radiation generated by second laser device 120, i.e., high-energy laser pulses 20 in this case. This advantageously ensures that pump laser 110 is not damaged by the high-energy laser pulses transferred, if necessary, to pump laser 110 via fiber optic device 130.