Abstract: A device for generating extreme ultraviolet (EUV) radiation includes an optical beam-forming arrangement with a focusing unit for forming a laser beam, and a target material configured to be irradiated with the laser beam to emit EUV radiation. The beam-forming arrangement includes a beam rotator for image field rotation of the laser beam.

Abstract: A method for monitoring a laser optical unit of a laser system includes guiding a laser beam through the laser optical unit, performing a first measurement of vibrations arising in the laser optical unit, structure-borne sound arising in the laser optical unit, and/or sound arising in the laser optical unit by using a sensor, and generating an output of the first measurement, and/or an output of a change of the vibrations, of the structure-borne sound, and/or of the sound.

Abstract: A laser focusing system (330) for use in an EUV radiation source is described, the laser focusing system comprising: •—a first curved mirror (330.1) configured to receive a laser beam from a beam delivery system (320) and generate a first reflected laser beam (316); •—a second curved mirror (330.2) configured to receive the first reflected laser beam (316) and generate a second reflected laser beam (317), wherein the laser focusing system (330) is configured to focus the second reflected laser beam (317) to a target location (340) in a vessel (350) of the EUV radiation source (360).

Abstract: 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.

Abstract: An EUV excitation light source includes a laser source configured to emit a laser beam. The laser beam includes two partial beams having different wavelengths. The EUV excitation light source further includes a separating optical element for separating the two partial beams of the laser beam into two separated beams, and a superposition unit for superimposing the two separated beams at a predefined superposition location with a predefined superposition angle. The separating optical element includes a first reflective diffraction grating.

Abstract: 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.

Abstract: A laser focusing system (330) for use in an EUV radiation source is described, the laser focusing system comprising: •—a first curved mirror (330.1) configured to receive a laser beam from a beam delivery system (320) and generate a first reflected laser beam (316); •—a second curved mirror (330.2) configured to receive the first reflected laser beam (316) and generate a second reflected laser beam (317), wherein the laser focusing system (330) is configured to focus the second reflected laser beam (317) to a target location (340) in a vessel (350) of the EUV radiation source (360).

Abstract: A method for producing a radiation field amplifying system for amplifying a to be amplified radiation field, in particular for producing a thin disc laser amplifying system, which comprises an amplifying element with a laser active body and a cooling system for cooling said amplifying element with at least one heat sink element wherein the method comprises the step of connecting said amplifying element and said at least one heat sink element is proposed by soldering with a solder filling composition, wherein the step of soldering comprises heating up, in particular melting, said solder filling composition by exposing said solder filling composition to a soldering radiation field.

Abstract: The present invention relates to an optical module configured to be optically coupleable to a laser amplifier module, the optical module comprising an inner optical element having a plurality of M inner reflective elements arranged around a center of the inner optical element; and a plurality of N outer reflective elements arranged around the inner optical element, the plurality of N outer reflective elements being configured to face the inner optical element, wherein the plurality of M inner reflective elements and the plurality of N outer reflective elements are configured to provide an optical path for a laser beam.

Abstract: The present disclosure provides a method and to a device for quantitatively sensing the power fraction of a radiation background of a pulsed laser. The disclosure further relates to the use of a saturable element. The method includes modulating a measurement beam, which is emitted by the laser, by means of a saturable element in accordance with the fluence of the measurement beam, detecting, by means of a modulation beam power detector, the power of the measurement beam modulated by the saturable element, and determining the power fraction of the radiation background of the pulsed laser on the basis of the detected power of the measurement beam modulated by means of the saturable element.

Abstract: The present disclosure provides a method and to a device for quantitatively sensing the power fraction of a radiation background of a pulsed laser. The disclosure further relates to the use of a saturable element. The method includes modulating a measurement beam, which is emitted by the laser, by means of a saturable element in accordance with the fluence of the measurement beam, detecting, by means of a modulation beam power detector, the power of the measurement beam modulated by the saturable element, and determining the power fraction of the radiation background of the pulsed laser on the basis of the detected power of the measurement beam modulated by means of the saturable element.

Abstract: The present invention relates to an optical module configured to be optically coupleable to a laser amplifier module, the optical module comprising an inner optical element having a plurality of M inner reflective elements arranged around a center of the inner optical element; and a plurality of N outer reflective elements arranged around the inner optical element, the plurality of N outer reflective elements being configured to face the inner optical element, wherein the plurality of M inner reflective elements and the plurality of N outer reflective elements are configured to provide an optical path for a laser beam.