Abstract: A vertical cavity surface emitting laser device includes: an optical resonator; a photodiode; and a contact arrangement. The optical resonator includes: two distributed Bragg reflectors (DBRs) and an active region between the DBRs. The photodiode has a light absorption region in the optical resonator. The contact arrangement provides drive current to pump the optical resonator, and contacts the photodiode. The active region has an InxGa1-xAs layer, where 0?x<1. The light absorption region has an InyGa1-yAs layer, where 0<y<1, and y>x. The InyGa1-yAs layer is an intrinsic layer of the light absorption region. The InyGa1-yAs layer is 15-50 nm thick. The light absorption region has an undoped layer with a material different from the InyGa1-yAs layer. The InyGa1-yAs layer is immediately adjacent to the undoped layer. An intrinsic zone of the light absorption region is at least 70 nm thick.

Abstract: The invention is based on a sensor device (10) with at least one sensor unit (12) comprising at least one laser unit (14) for a generation of at least one laser beam (16) and comprising at least one detection unit (18) for a detection of, in particular reflected, laser beams (20), with an evaluation unit (22) which is configured to process detected laser beams (20) into at least one sensor signal (39), and with a control unit (26) which is configured, in a continuous operation state, to actuate the sensor unit (12) and the evaluation unit (22) for an operation of the sensor unit (12) and the evaluation unit (22) in alternating switch-on intervals (31, 43) and switch-off intervals (33, 45). It is proposed that the evaluation unit (22) is configured to generate the at least one sensor signal (39) from at least two different switch-on intervals (31) of the sensor unit (12).

Abstract: A vertical cavity surface emitting laser (VCSEL) emits laser light. The VCSEL has an optical resonator and a photodiode. The optical resonator has: a first mirror, an active region configured to generate laser light, and a second mirror. The active region is arranged between the first mirror and the second mirror. The photodiode is integrated in the optical resonator. The photodiode has: an absorption region having a plurality of absorbing layers configured to absorb the generated laser light. The absorbing layers are arranged spaced apart from one another by a distance d which satisfies the condition: d=(2k?1)?/(4 m). Where ? is the wavelength of the laser light in the absorption region, and k and m are natural numbers ?1.

Abstract: 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.

Abstract: A laser arrangement includes a laser array including a plurality of Vertical Cavity Surface Emitting lasers and an optical structure including a diffuser arranged to change a distribution of the laser light. The optical structure is configured to transform the laser light to transformed laser light such that an overlap of the emission cones of at least a group of the plurality of lasers is increased in field-of-view in comparison to perfectly collimated laser light diffused to a flat-top intensity profile in the field-of-view. The optical structure is arranged to redirect the laser light emitted at angles of the emission cone to the field-of-view so as to increase the overlap of the emitted laser light in the field-of-view. The optical structure is also configured to provide a slope angle ? of an intensity profile along a direction of the field-of-view that is smaller than a divergence angle of the laser.

Abstract: A vertical cavity surface emitting laser includes four contacts and an optical resonator (having two Bragg reflectors, a photodiode, and an active layer between the Bragg reflectors). The second Bragg reflector has three parts. The first part has a pair of layers with different refractive indices and a second conductivity type. The second part has a pair of layers with different refractive indices and a first conductivity type. The third part has a pair of layers with different refractive indices and the second conductivity type. A light absorption structure of the photodiode is between the second and third parts. The first and second electrical contacts provide a current to pump the resonator. The light absorption structure is outside the current path. The third and fourth electrical contacts contact the photodiode. The second and third electrical contact respectively contact the first and second parts and are separated by a semiconductor layer.

Abstract: VCSELs have a substrate, first and second electrical contacts (ECs), and an optical resonator (OR), having first and second distributed Bragg reflectors (DBRs) and an active layer between the DBRs. The first DBR is between the substrate and the active layer. One of the DBRs has: first and second parts, having different conductivity types, and each with a pair of layers with different refractive indices. A tunnel junction (TJ) is between the parts. The ECs are for electrically pumping the OR such that the TJ is reversely biased during operation of the VCSEL. Either the first DBR includes the parts, having a relative thickness of the second part to a total thickness of the first and second parts between 0.1-0.8, or the second DBR has the parts, the second part being on the TJ facing away from the active layer, and the relative thickness being between 0.15-0.6.

Abstract: A laser device includes a laser diode configured to emit radiation, an output power of the radiation being dependent on a laser diode driving current, and a photodiode configured to receive the radiation emitted by the laser diode. A photodiode current induced in the photodiode by the received radiation is dependent on a power of the received radiation. The laser device further includes circuitry configured to measure the photodiode current for a laser diode driving current and calculate a laser threshold current of the laser diode from the measured photodiode current as a measure of an actual laser threshold current of the laser diode. The circuitry is further configured to detect a malfunction or degradation of the laser diode.

Abstract: An optical arrangement of data smart glasses includes a first laser device configured to emit a projection light beam, a second laser device configured to emit a measuring light beam, a first scanner, a second scanner, and a beam combiner configured to bundle the projection light beam and the measuring light beam into a common light beam, wherein the first scanner is configured to deflect the projection light beam emitted by the first laser device in a first axis, and wherein the second scanner is configured to deflect the common light beam focused by the beam combiner in a second axis.

Abstract: A guiding system guides an autonomous movable object. The guiding system has a time-of-flight imaging system, which has a first light source to illuminate a first field of detection; and a light sensor. The light sensor detects first and second reflected light. The first reflected light has light emitted by the first light source reflected at the first field of detection. The second reflected light originates from a second field of detection illuminated by a second light source, which is independent from the first light source and is coupled to a different movable object. The imaging system differentiates between the first and second reflected light, determines a depth map of the first field of detection based on the detected first reflected light, and generates feedback. The imaging system has a motion controller that receives the feedback, and modifies a motion of the autonomous movable object based on the feedback.

Abstract: A method of forming an electrical metal contact within a semiconductor layer stack of a vertical cavity surface emitting laser includes forming a contact hole into the semiconductor layer stack. The contact hole has a bottom and a side wall extending from the bottom. The method further includes providing a photoresist mask inside the contact hole. The photoresist mask covers the side wall of the contact hole and has an opening extending to the bottom of the contact hole. The method additionally includes wet-chemical isotropic etching the bottom of the contact hole, depositing a metal on the bottom of the contact hole, and removing the photoresist mask so that the metal on the bottom of the contact hole is left as the electrical metal contact.

Abstract: A laser sensor module includes a first laser source configured to emit first modulated light, the first modulated light being modulated laser light. The laser sensor module further includes circuitry configured to drive the first laser source with a first modulated driving current to cause the first laser source to emit the modulated laser light, a detector configured to detect the modulated laser light, which induces a photocurrent with variations resulting from modulation of the modulated laser light, and a second laser source configured to emit second modulated light. The circuitry is further configured to drive the second laser source with a second modulated driving current to cause the second laser source to emit the second modulated light. The detector is configured to detect the second modulated light. The circuitry is configured to adapt the amplitude of the second modulated driving current to induce a contribution to the photocurrent.

Abstract: 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.

Abstract: The invention relates to an eye tracking arrangement that includes a camera configured to capture images of an eye at a first scanning rate, a laser velocimeter configured to capture an eye velocity of a movement of the eye by laser Doppler velocimetry at a second scanning rate and a control device configured to determine an absolute eye position based on the images, and track a gaze direction of the eye based on the absolute eye position and the eye velocity.

Abstract: A laser sensor module for detecting a particle density of small particles with a particle size between 0.05 ?m and 10 ?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.

Abstract: The invention relates to a method for detecting particles, having the steps of: receiving (S1) a measurement signal; calculating (S2) at least one estimated noise value using the received measurement signal; and detecting (S3) the particles using the measurement signal on the basis of at least one detection criterion, wherein the at least one detection criterion depends on the at least one calculated estimated noise value.

Abstract: The present invention provides methods and an apparatus for monitoring the optical output power of a laser diode (LD) having an associated photodiode (PD), and a particle sensor apparatus. The photodiode (PD) is operable together with the laser diode (LD), wherein it detects the light (LS) of the laser diode (LD) and converts it into an electrical current, and is thermally coupled to the laser diode (LD). Monitoring of the optical output power P is effected during the operation of the laser diode (LD) and is based on current measurements and/or voltage measurements at the laser diode (LD) and at the photodiode (PD).

Abstract: A VCSEL device includes a first electrical contact, a substrate, a second electrical contact, and an optical resonator arranged on a first side of the substrate. The optical resonator includes a first reflecting structure comprising a first distributed Bragg reflector, a second reflecting structure comprising a second distributed Bragg reflector, an active layer arranged between the first and second reflecting structures, and a guiding structure. The guiding structure is configured to define a first relative intensity maximum of an intensity distribution within the active layer at a first lateral position such that a first light emitting area is provided, to define at least a second relative intensity maximum of the intensity distribution within the active layer at a second lateral position such that a second light emitting area is provided, and to reduce an intensity in between the at least two light-emitting areas during operation.

Abstract: The invention relates to a method for determining the absolute value of the flow velocity (v) of a particle-transporting medium. At least two measurement laser beams (L_i) with linearly independent, non-orthogonal measurement directions (b_i) are emitted. The measurement laser beams (L_i) scattered at particles are detected and one measurement signal (m_i) is generated in each case for each measurement laser beam (L_i).

Abstract: A VCSEL device includes a first electrical contact, a substrate, a second electrical contact, and an optical resonator arranged on a first side of the substrate. The optical resonator includes a first reflecting structure comprising a first distributed Bragg reflector, a second reflecting structure comprising a second distributed Bragg reflector, an active layer arranged between the first and second reflecting structures, and a guiding structure. The guiding structure is configured to define a first relative intensity maximum of an intensity distribution within the active layer at a first lateral position such that a first light emitting area is provided, to define at least a second relative intensity maximum of the intensity distribution within the active layer at a second lateral position such that a second light emitting area is provided, and to reduce an intensity in between the at least two light-emitting areas during operation.