US Patent 11968767 EUV light source with a separation device

A EUV light source includes a prepulse laser source for emitting a prepulse laser beam at a prepulse wavelength, a main pulse laser source for emitting a main pulse laser beam at a main pulse wavelength, a prepulse beam guiding device for feeding the prepulse laser beam into a radiation generating chamber for irradiation of a target material with a prepulse, and a main pulse beam guiding device for feeding the main pulse laser beam into the radiation generating chamber for irradiation of the target material with a main pulse. The target material is configured to emit EUV radiation on account of the irradiation with the prepulse and the main pulse. The prepulse beam guiding device has a separation device configured to reflect disturbing radiation in a wavelength range that does not include the prepulse wavelength back into the radiation generating chamber or into at least one beam trap.