Vibrometer and method for optically measuring an object

US8199331B2 · kind B2 · utility

Assignee

• Polytec GmbH · CA

Inventors

• Christian Rembe · Waldbronn, DE
• Georg Siegmund · Waldbronn, DE
• Tian-Hua Xu · Waldbronn, DE

Key dates

• Filing date: Apr 2, 2009
• Grant date: Jun 12, 2012
• Expiry date: Jul 29, 2030

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B9/02002
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A vibrometer and a method for optically measuring oscillations at an object, including a radiation source for creating a source beam, a beam splitter to split the source beam into a measuring beam and a reference beam, an optic interference device for interfering the reference beam with a measuring beam, at least partially reflected by the object, and a detector, with the interference device and the detector being embodied cooperating such that a measuring beam, at least partially deflected by the object, and the reference beam interfere on the detector. The vibrometer is embodied as a heterodyne vibrometer, having an optic frequency shift unit, which is arranged in the optical path of the vibrometer, to form a carrier frequency by creating a frequency difference between the measuring beam and the reference beam. The beam splitter and the frequency shift unit are embodied as an acousto-optic modulator in an optic construction element to deflect the source beam, with the acousto-optic modulator being embodied such that the source beam entering the acousto-optic modulator can be split into at least two diffraction beams: a first diffraction beam of diffraction order of 1 and a second…