Abstract: In one implementation, a beam guiding apparatus includes a vacuum chamber that includes a target region arranged to receive a target material for generating EUV radiation. The vacuum chamber further includes a first opening for receiving into the vacuum chamber a first laser beam and a second opening for receiving into the vacuum chamber a second laser beam. The vacuum chamber also includes a superposition apparatus arranged to superpose the first laser beam having a first wavelength and a second laser beam having a second wavelength for common beam guidance in the direction of the target region. The vacuum chamber also includes a beam shaping apparatus arranged upstream of the superposition apparatus in the beam path of the second laser beam, wherein the beam shaping apparatus is configured to set a ring-shaped beam profile of the second laser beam, The first and second laser beam have different wavelengths.

Abstract: The invention relates to an optical arrangement comprising an optical module having a first carrier body to which there are attached at least one optical element and a plurality of first mounting elements, and a housing having a second carrier body for at least one further optical element, wherein a plurality of second mounting elements is attached to the carrier body. Also comprised is a movement device for displacing the first carrier body relative to the second carrier body in a movement direction between a removal position from which the optical module can be removed from the housing and a mounting position in which the movement device presses the first mounting elements against the second mounting elements. The invention relates also to an optical module and to a method for correctly positioning an optical module in a housing.

Abstract: A device for amplifying a laser beam is provided. The device includes at least one amplifier chamber in which a laser-active material is provided, at least one transmitting optical member delimiting the amplifier chamber and being arranged at a tilt angle, ?, with respect to a plane oriented perpendicularly with respect to an optical axis of the laser beam, and at least one detection unit. The laser beam is reflected by the transmitting optical member into a back reflected laser beam, and the detection unit is arranged such that it detects the back reflected laser beam.

Abstract: An Extreme Ultra-Violet (EUV) excitation light source has a beam guide device for manipulating at least one laser beam is provided. The beam guide device comprises at least one beam splitter for generating at least two separated beams from at least one laser beam, at least one mirror or a lens for manipulating at least one of the separated beams, a superposition mirror for superposing the at least two separated beams, and a focusing appliance for generating a respective focus for each of the at least two separated beams. At least two focuses can be generated at one identical location or at two different locations by the beam guide device.