Trumpf Photonic Components Gmbh

Robert Boschgmbh

Alexander Marc Van Der Lee

Johannes Hendrikus Maria Spruit

Petrus Theodorus Jutte

Okke Ouweltjes

Philipp Henning Gerlach

Robert Wolf

Robert Weiss

Matthias Falk

Hans Spruit

Jeroen Dragt

Joachim Wilhelm Hellmig

Pieter Hoeven

A method reduces false-positive particle counts detected by an interference particle sensor module, which has a laser and a light detector. The method including: emitting laser light; providing a high-frequency signal during the emission of the laser light, a modulation frequency of the high-frequency signal being between 10-500 MHz; detecting an optical response by the light detector in reaction to the emitted laser light while providing the high-frequency signal, which is arranged such that a detection signal caused by a macroscopic object positioned between a first and second distance is reduced in comparison to a detection signal caused by the macroscopic object at the same position without providing the high-frequency signal. The high-frequency signal is provided to a tuning structure of the particle sensor module which is arranged to modify a resonance frequency of an optical resonator comprised by the laser sensor module upon reception of the high-frequency signal.

Method of reducing false-positive particle counts of an interference particle sensor module

A method of measuring a particle density of particles includes emitting, by a laser, a laser beam directed to a mirror, redirecting the laser beam by the mirror with a predetermined periodic movement, and focusing the laser beam to a detection volume by an optical imaging device. The method further includes determining a self mixing interference signal of an optical wave within a laser cavity if the self mixing interference signal is generated by laser light of the laser beam reflected by at least one of the particles and suppressing a false self mixing interference signal for particle detection if the self mixing interference signal is caused by a disturbance in an optical path of the laser beam. The false self mixing signal caused by the disturbance in the optical path of the laser beam is suppressed in a defined range of angles of the mirror during the periodic movement.

Method of suppressing false positive signals during self mixing interference particle detection

Growing community of inventors

Ulm, Germany

Alexander Marc Van Der Lee