Arrangement and photometer for measuring and controlling the thickness of optically active thin layers

US4207835A · kind A · utility

Assignee

• Leybold-Heraeus GmbH & Co. KG · DE

Inventors

• Horst Schwiecker
• Gernot Thorn · Hanau, DE
• Hans-Peter Ehrl · Erding, DE

Key dates

• Filing date: Jun 16, 1977
• Grant date: Jun 17, 1980
• Expiry date: Jun 16, 1997

Classification

• Technology area (CPC G): Physics
• CPC primary: G05D5/03
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An arrangement and photometer for measuring and controlling the thickness of optically active thin layers wherein the axis of the measurement light beam coming from the measurement light source is directed to the measurement object and a referenced light receiver, independent of the optical properties of the measurement object, is associated with the measurement light beam. The output signal of the referenced light receiver is mixed with a trigger stage for a phase sensitive photometer amplifier and is fed to a compensation circuit for the equilization of brightness variations in the measurement light source.