Optical assembly for reducing a spectral bandwidth of an output beam of a laser

US12300959B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Johannes Kraus · Gerbrunn, DE
• Oliver Gloeckl · Aalen, DE
• Markus Deubel · Schweighofen, DE

Key dates

• Filing date: Dec 10, 2020
• Grant date: May 13, 2025
• Expiry date: Jul 11, 2043

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S3/225
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An optical assembly reduces a spectral bandwidth of an output beam of a laser. The assembly includes a beam-expanding optical unit within a laser resonator. The latter serves to increase a beam cross section of a resonator-internal laser beam in at least one expansion cross-sectional dimension such that at least one resonator-internal expansion laser beam section arises. The assembly also includes an optical grating in a retroreflective arrangement for the resonator-internal laser beam. A beam-limiting stop acts in the expansion cross-sectional dimension and is arranged in the beam path of the expansion laser beam section. This yields an optical assembly in which unwanted thermal effects on account of optical components of the optical assembly heating during laser operation due to a local power density of the resonator-internal laser beam are reduced or avoided.