Trumpf Photonic Components Gmbh

Koninklijke Philips Corporation N.v.

Philips Photonics Gmbh

Joachim Wilhelm Hellmig

Alexander Marc Van Der Lee

Holger Joachim Moench

Johannes Hendrikus Maria Spruit

Petrus Theodorus Jutte

Cornelis Reinder Ronda

Okke Ouweltjes

Gerben Kooijman

Arnoldus Johannes Martinus Jozeph Ras

Roy Ovink

Matthew John Lawrenson

Koray Karakaya

Ulrich Weichmann

Jan Matthijs Ter Meulen

Jan Jasper Van Den Berg

Pascal De Graaf

Pieter Hoeven

Nicholas Walker

Ralph Engelbertus Theodorus Gudde

Robert Van Der Kloet

Johannes Henrikus Maria Spruit

Holger Joachim MÖNCH

A time-of-flight depth camera includes a VCSEL array, an optical arrangement, an evaluator and a light detector having at least one detector pixel. The VCSEL array or the optical arrangement are arranged to provide different illumination patterns in a reference plane in a defined field-of-view of the time-of-flight depth camera. The light detector is arranged to detect the different illumination patterns and the evaluator is arranged to reconstruct a depth image of the field of view with a resolution of a predefined number of pixels P based on the detected different illumination patterns. A number of the detected different illumination patterns N is at least 5% of the predefined number of pixels P, preferably at least 10% of the predefined number of pixels P and most preferred at least 20% of the predefined number of pixels P.

Time-of-flight depth camera with low resolution pixel imaging

A laser sensor module for detecting a particle density of small particles with a particle size between 0.05 &#x3bc;m and 10 &#x3bc;m includes a first laser configured to emit a first measurement beam, a second laser configured to emit a second measurement beam, and an optical arrangement configured to focus the first measurement beam to a first measurement volume and to focus the second measurement beam to a second measurement volume. The optical arrangement includes a first numerical aperture and a second numerical aperture arranged to detect a predetermined minimum particle size. The laser sensor module further includes a first detector configured to determine a first self-mixing interference signal of a first optical wave, a second detector configured to determine a second self-mixing interference signal of a second optical wave, and an evaluator.

Optical particle sensor module

The invention describes a laser sensor or laser sensor module () using self-mixing interference for particle density detection, a related method of particle density detection and a corresponding computer program product. The invention further relates to devices comprising such a laser sensor or laser sensor module. It is a basic idea of the present invention to detect particles by means of self-mixing interference signals and determine a corresponding particle density. In addition at least a first parameter related to at least one velocity component of a velocity vector of the particles is determined in order to correct the particle density if there is the relative movement between a detection volume and the particles. Such a relative movement may for example be related to a velocity of a fluid transporting the particles (e.g. wind speed). Furthermore, it is possible to determine at least one velocity component of the velocity of the particles based on the self-mixing interference signals.

Laser sensor for particle detection

A laser sensor for detecting a particle density includes: a laser configured to emit a measurement beam, an optical arrangement being arranged to focus the measurement beam to a measurement volume, the optical arrangement having a numerical aperture with respect to the measurement beam, a detector configured to determine a self-mixing interference signal of a optical wave within a laser cavity of the laser, and an evaluator. The evaluator is configured to: receive detection signals generated by the detector in reaction to the determined self-mixing interference signal, determine an average transition time of particles passing the measurement volume in a predetermined time period based on a duration of the self-mixing interference signals generated by the particles, determine a number of particles based on the self-mixing interference signals in the predetermined time period, and determine the particle density based on the average transition time and the number of particles.

Laser sensor module for particle density detection

The invention describes a laser sensor module () for detecting ultra-fine particles () with a particle size of 300 nm or less, more preferably 200 nm or less, most preferably 100 nm or less, the laser sensor module () comprising: &#x2014;at least one laser () being adapted to emit laser light to at least one focus region in reaction to signals provided by at least one electrical driver (), &#x2014;at least one detector () being adapted to determine a self-mixing interference signal of an optical wave within a laser cavity of the at least one laser (), wherein the self-mixing interference signal is caused by reflected laser light reentering the laser cavity, the reflected laser light being reflected by a particle receiving at least a part of the laser light, &#x2014;the laser sensor module () being arranged to perform at least one self-mixing interference measurement, &#x2014;the laser sensor module () being adapted to determine a first particle size distribution function with a first sensitivity by means of at least one measurement result determined based on the at least one self-mixing interference measurement, the laser sensor module being further adapted to determine a second particle size distribution function with the second sensitivity, the second sensitivity being different from the first sensitivity, &#x2014;the at least one evaluator () being adapted to determine a particle measure of the particle size of 300 nm or less by subtracting the second particle size distribution function multiplied with a calibration factor q from the first particle size distribution function. The invention further describes a corresponding method and computer program product. The invention enables a simple and low-cost particle detection module or particle detector based on laser self-mixing interference which can detect particles with a size of 100 nm or even less.

Laser sensor for ultra-fine particle size detection

A display apparatus configured to be coupled to a movable object includes at least a first laser sensor module and a display device configured to display a field-of-view. The first laser sensor module is configured to determine, by self mixing interference measurements, movements of the movable object with respect to a reference object mechanically coupled to the movable object. The first laser sensor module is configured to emit at least three measurement beams in three different spatial directions to the reference object when the display apparatus is coupled to the movable object and the first laser sensor module is configured to determine velocity vectors or distances collinear to the spatial directions. The display device is configured to integrate at least one virtual object in the field-of-view in accordance with the determined movements of the movable object.

Display apparatus for computer-mediated reality

The invention describes a laser sensor module. The laser sensor module comprises at least a first laser () being adapted to emit a first measurement beam (') and at least a second laser () being adapted to emit a second measurement beam (&#x2032;). The laser sensor module further comprises an optical device () being arranged to redirect the first measurement beam (&#x2032;) and the second measurement beam (&#x2032;) such that the first measurement beam (&#x2032;) and the second measurement beam enclose an angle between 45&#xb0; and 135&#xb0;. The laser sensor module comprises one detector () being adapted to determine at least a first self-mixing interference signal of a first optical wave within a first laser cavity of the first laser () and at least a second self-mixing interference signal of a second optical wave within a second laser cavity of the second laser (). This configuration enables determination of an average velocity of the particles despite of the fact that it is not possible to determine the components of the velocity vector. The introduced error by means of statistical variations is acceptable because the number of detected particles scales with the cubic root of the particle velocity. The invention further describes a particle sensor () comprising such a laser sensor module, a corresponding method and computer program product. The invention enables a simple and low-cost particle sensor () for detecting small particles based on laser self-mixing interference.

Optical particle sensor

The invention describes a laser sensor module () for particle density detection. The laser sensor module () comprising at least one first laser (), at least one first detector () and at least one electrical driver (). The first laser () is adapted to emit first laser light in reaction to signals provided by the at least one electrical driver (). The at least one first detector () is adapted to detect a first self-mixing interference signal of an optical wave within a first laser cavity of the first laser (). The first self-mixing interference signal is caused by first reflected laser light reentering the first laser cavity, the first reflected laser light being reflected by a particle receiving at least a part of the first laser light. The laser sensor module () is adapted to reduce multiple counts of the particle. The invention further describes a related method and computer program product.

Laser sensor for particle density detection

The invention describes a laser sensor module () for particle size detection. The laser sensor module () comprises at least one first laser (), at least one first detector (), at least one electrical driver () and at least one evaluator (). The first laser () is adapted to emit first laser light in reaction to signals provided by the at least one driver (). The at least one first detector () is adapted to determine a first self-mixing interference signal () of an optical wave within a first laser cavity of the first laser (). The first self-mixing interference signal () is caused by first reflected laser light reentering the first laser cavity, the first reflected laser light being reflected by a particle receiving at least a part of the first laser light. The evaluator () is adapted to determine a size of the particle by determining a first relative distance between the particle and the first laser () by means of the first self-mixing interference signal () and by determining a first amplitude information by means of the first self-mixing interference signal (). The invention is further related to a corresponding method of determining a particle size.

Laser sensor for particle size detection

A method for determining operating conditions of a particle detector that includes a multimode Vertical Cavity Surface Emitting Laser (VCSEL) includes providing an electrical drive current to the multimode VCSEL such that a laser beam is emitted by the multimode VCSEL and varying the electrical drive current within a predefined range of electrical drive currents. The method further includes determining, as a function of the electrical drive current, an intensity signal of an optical wave within a laser cavity of the multimode VCSEL, determining, as a function of the electrical drive current, a noise measure of the intensity signal, determining a range of electrical drive currents for which the noise measure is below a predefined threshold noise measure value, and determining operating conditions of the particle detector by choosing an electrical drive current for particle detection out of the determined low noise range of electrical drive currents.

Method of determining operation conditions of a laser-based particle detector

The invention describes an illumination device () for illuminating a three dimensional arrangement () in an infrared wavelength spectrum. The illumination device () comprises at least a first group of laser devices () comprising at least one laser device () and at least a second group of laser devices () comprising at least one laser device (). The first and the second group of laser devices () are adapted to be operated independent with respect to each other. The first group of laser devices () is adapted to emit laser light with a first emission characteristic and the second group of laser devices () is adapted to emit laser light with a second emission characteristic different from the first emission characteristic. The invention further describes a distance detection device () and a camera system () comprising such an illumination device (). The different emission characteristics may be used to compensate or take into account the depth of the three dimensional arrangement (). Different parts of the three dimensional arrangement () may be illuminated by means of the first and second emission characteristic in different ways.

Infrared laser illumination device

The invention describes a laser sensor module () which is adapted to detect or determine at least two different physical parameters by means of self-mixing interference by focusing a laser beam to different positions. Such a laser sensor module () may be used as an integrated sensor module, for example, in mobile devices (). The laser sensor module () may be used as an input device and in addition as a sensor for detecting physical parameters in an environment of the mobile communication device (). One physical parameter in the environment of the mobile communication device () may, for example, be the concentration of particles in the air (air pollution, smog . . . ). The invention further describes a related method and computer program product.

Laser sensor for multi parameter detection

A method and recording device for recording marks in a phase-change type record carrier uses increased cooling period between pulses in a sequence of write pulses by applying m write pulses, where m is depended on n/&#x3b1; (&#x3b1; being an integer larger than 1). The number of write pulses m may be set to the integer value closest to n/&#x3b1;.

Method and device for recording marks in an information layer of an optical record carrier

A device and method of recording marks representing data in an information layer of a record carrier includes irradiating the information layer by a pulsed radiation beam, each mark being written by a sequence of pulses. The recorded marks are erasable by irradiating the information layer with an erase radiation beam. The erase radiation beam has a first erase power level (e) for a first erase period (t), a second erase power level (e) higher than or equal to the first erase power level (e) for a second erase period (t) , and a third erase power level (e) lower than the second erase power level (e) for a third erase period (t).

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Eindhoven, Netherlands

Joachim Wilhelm Hellmig