Method and device for characterizing the surface shape of an optical element

US11326872B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Steffen SIEGLER · Aalen, DE
• Thomas Schicketanz · Aalen, DE

Key dates

• Filing date: Jan 15, 2021
• Grant date: May 10, 2022
• Expiry date: Jan 15, 2041

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B2290/70
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and a device for characterizing the surface shape of an optical element. In the method, in at least one interferogram measurement carried out by an interferometric test arrangement, a test wave reflected at the optical element is caused to be superimposed with a reference wave not reflected at the optical element. In this case, the figure of the optical element is determined on the basis of at least two interferogram measurements using electromagnetic radiation having in each case linear input polarization or in each case circular input polarization, wherein the input polarizations for the two interferogram measurements differ from one another.