Excimer laser with improved beam uniformity and stability
AssigneeCoherent LaserSystems GmbH & Co. KG
InventorsIgor Bragin, Jozsef Bekesi
Life of this patent
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Abstract
An excimer laser includes a chamber for containing a gas mixture between a rear end and a front end of a linear laser resonator, a convex end-mirror defining the rear end, and a plurality of output-coupling mirrors collectively defining the front end. The output-coupling mirrors are distributed along an optical axis of the resonator and have respective normal vectors pointing toward the rear end. The normal vectors include four mutually non-parallel normal vectors, wherein no three of the four mutually non-parallel normal vectors are coplanar. These different orientations of the output-coupling mirrors cooperate with the convex end-mirror to blur fine structure in the output beam of the resonator.
Claims19
An excimer laser, comprising:
- a chamber configured to contain a gas mixture between a rear end and a front end of a linear laser resonator;
- a convex end-mirror defining the rear end, the convex end-mirror having adjustable curvature;
- and
- a plurality of output-coupling mirrors that (a) are distributed along an optical axis of the linear laser resonator, (b) collectively define the front end, and (c) have a respective plurality of normal vectors pointing toward the rear end, the plurality of normal vectors including four mutually non-parallel normal vectors, wherein no three of the four mutually non-parallel normal vectors are coplanar.
An excimer laser, comprising:
- a chamber configured to contain a gas mixture between a rear end and a front end of a linear laser resonator;
- a convex end-mirror defining the rear end;
- and
- a plurality of output-coupling mirrors that (a) are distributed along an optical axis of the linear laser resonator, (b) collectively define the front end, and (c) have a respective plurality of normal vectors pointing toward the rear end, the plurality of normal vectors including four mutually non-parallel normal vectors, wherein no three of the four mutually non-parallel normal vectors are coplanar;
- wherein the output-coupling mirrors include a plurality of output-coupling mirror pairs, each output-coupling mirror pair being rear-facing and front-facing surfaces of a wedge having a symmetry axis located in a mirror plane between the rear-facing and front-facing surfaces and coplanar with the normal vectors of the rear-facing and front-facing surfaces, the respective symmetry axes of the wedges being mutually non-parallel and oriented at different respective azimuthal angles about the optical axis, the wedges being held against each other in a stack with a spacer between each pair of adjacent wedges.
Dependencies are inferred from the claim text.