Reference interferometer with variable wavelength and folded measurement beam path

US5715057A · kind A · utility

Assignee

• Carl Zeiss Jena GmbH · DE

Inventors

• Karl-Heinz Bechstein · Jena, DE
• Beate Moeller · Jena, DE
• Klaus Salewski · Greifswald, DE

Key dates

• Filing date: Jun 20, 1996
• Grant date: Feb 3, 1998
• Expiry date: Jun 20, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B9/02056
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention is directed to a reference interferometer with variable wavelength, with an interferometer splitter, a reference beam path, and a folded measurement beam path passing between two plane mirrors. At least one spacer element 10 is provided for realizing a fixed position of the plane mirrors relative to one another. The two plane mirrors are arranged in a plurality of planes in a defined manner in relation to one another such that a light beam coming from the interferometer splitter and coupled into the space between the plane mirrors at an entrance point at a slight angle is reflected repeatedly at the plane mirrors, and the reflection points lie along a parabola on the surfaces of the plane mirrors. A retroreflector is arranged downstream of the first plane mirror in such a way that the light beam striking it can be returned to the entrance point or in the vicinity thereof along the same path or almost the same path.