Laser sensor, system and method for self-mixing interferometry

US12241741B2 · kind B2 · utility

Assignees

• TRUMPF PHOTONIC COMPONENTS GMBH · DE
• Robert Bosch GmbH · DE

Inventors

• Hans Spruit · Waalre, NL
• Jochen Hellmig · Ulm, DE
• Stephan Gronenborn · Aachen, DE
• Johannes Meyer · Karlsfeld, DE
• Andreas Petersen · Erbach, DE
• Thomas Alexander Schlebusch · Renningen, DE

Key dates

• Filing date: Apr 27, 2022
• Grant date: Mar 4, 2025
• Expiry date: Dec 30, 2042

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B2027/0178
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A laser sensor includes a laser source configured to emit a laser beam, and optics configured to project the laser beam as a one- or two-dimensional patterned laser beam onto an object to be examined, such that a distance of the patterned laser beam from the laser source varies along the patterned laser beam projected on the object. The laser sensor further includes a detector configured to determine a self-mixing interference signal generated by laser light of the patterned laser beam reflected from the object back into the laser source, and circuitry configured to analyze a spectrum of the self-mixing interference signal and extract from the spectrum of the self-mixing interference signal multiple frequencies that are indicative of at least one of the following: multiple distances along the patterned laser beam from the laser source, or multiple velocities along the patterned laser beam with respect to the laser source.