Optical apparatus for determining the caustic of a laser beam, method for determining the caustic of a laser beam using an optical apparatus, EUV driven laser, EUV light generating equipment, and method for manufacturing semiconductor intermediate products or microchips.

Abstract

The present invention relates to an optical device (10) for determining the beam caustics of a laser beam (12), the optical device having a coupling device (14) configured to couple a measurement beam separated from the laser beam (12) to a measurement beam path. A detection device (18) having an imaging plane (20) is configured to capture multiple images of the measurement beam (22) in the imaging plane (20). The beam caustics of the measurement beam can be determined from the multiple images of the measurement beam (22) by an evaluation device (24). A deflection device (26) having a deflection surface (28) is provided and positioned such that the measurement beam from the direction of the coupling device (14) is deflected toward the imaging plane (20) of the detection device (18) by the deflection surface (28). According to the invention, the detection device (18) is fixed in position immovably, and the imaging plane (20) of the detection device (18) is fixed. The deflection surface (28) is designed to be at least partially reversibly deformable, so that the focal length of the deflection device (26) can be adjusted by at least partially deforming the deflection surface (28), thereby generating multiple images of the measurement beam in the imaging plane (20) of the detection device (18) at different focal lengths.

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