Method of measuring a shape of an optical surface based on computationally combined surface region measurements and interferometric measuring device

US8593642B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Rolf Freimann · Aalen, DE
• Bernd Doerband · Aalen, DE
• Stefan Schulte · Marburg, DE
• Albrecht Hof · Aalen, DE
• Frank Riepenhausen · Oberkochen, DE
• Matthias Manger · Neukochen, DE
• Dietmar Neugebauer · Pfaffenhofen an der Ilm, DE
• Helmut ISSLER · Prien am Chiemsee, DE
• Armin Bich · Aalen, DE

Key dates

• Filing date: Mar 12, 2012
• Grant date: Nov 26, 2013
• Expiry date: Mar 12, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B2290/15
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Measuring a shape of an optical surface (14) of a test object (12) includes: providing an interferometric measuring device (16) generating a measurement wave (18); arranging the measuring device (16) and the test object (12) consecutively at different measurement positions relative to each other, such that different regions (20) of the optical surface (14) are illuminated by the measurement wave (18); measuring positional coordinates of the measuring device (16) at the different measurement positions in relation to the test object (12); obtaining surface region measurements by interferometrically measuring the wavefront of the measurement wave (18) after interaction with the respective region (20) of the optical surface (14) using the measuring device (16) in each of the measurement positions; and determining the actual shape of the optical surface (14) by computationally combining the surface region measurements based on the measured positional coordinates of the measuring device (16) at each of the measurement positions.