Method for generating a two-dimensional interferogram using a michelson-type open-beam interferometer

US11421979B2 · kind B2 · utility

Assignee

• Visotec GmbH · DE

Inventors

• Michael Münst · Lübeck, DE
• Helge Sudkamp · Lübeck, DE
• Peter Koch · Wulfen, DE
• Gereon Hüttmann · Wulfen, DE

Key dates

• Filing date: Jan 25, 2019
• Grant date: Aug 23, 2022
• Expiry date: Mar 4, 2039

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B9/02032
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a method for creating a two-dimensional interferogram with a Michelson-type free-beam interferometer, comprising an extended, partially spatially coherent light source and a two-dimensional light detector, wherein light from the light source is split by a beam splitter with a semitransparent beam splitter mirror into a sample light beam and a reference light beam and taken to a sample arm and a reference arm, wherein the sample light beam returning from a sample is directed by the beam splitter mirror onto the light detector, wherein the reference light beam emerging from the reference arm makes a predetermined angle greater than zero with the sample light beam on the light detector, and wherein the length of the reference arm is variable, where the reference light beam is directed by means of an odd number of reflections in each reflection plane in at least one reference arm section so that it is displaced laterally to itself and travels antiparallel through a light-deflecting element working by refraction or diffraction which is secured at the exit of the reference arm.