Interferometric measuring arrangement

US10337850B2 · kind B2 · utility

Assignee

• Carl Zeiss SMT GmbH · DE

Inventors

• Jochen Hetzler · Aalen, DE
• Sebastian Fuchs · Aalen, DE
• Hans-Michael Stiepan · Aalen, DE
• Karl-Heinz Schuster · Oberkochen, DE

Key dates

• Filing date: Nov 22, 2017
• Grant date: Jul 2, 2019
• Expiry date: Nov 22, 2037

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B2290/30
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A measurement arrangement (10) and an associated method for interferometrically determining the surface shape (12) of a test object (14) includes a light source (16) providing an input wave (18) and a diffractive optical element (24). The diffractive optical element is configured to produce in each case by way of diffraction from the input wave a test wave (26), which is directed at the test object (14) and has a wavefront that is adapted at least partially to a desired shape of the optical surface, and a reference wave (28). The measurement arrangement furthermore includes a reflective optical element (30) that back-reflects the reference wave (28) and a capture device (36) that captures an interferogram produced by superposing the test wave after interaction with the test object and the back-reflected reference wave (28), in each case after a further diffraction at the diffractive optical element in a capture plane (48).