Koninklijke Philips Corporation N.v.

Trumpf Photonic Components Gmbh

Robert Boschgmbh

Philipp Henning Gerlach

Robert Wolf

Alexander Weigl

Susanne Weidenfeld

Soren Sofke

Roger King

Holger Joachim Moench

Alexander Marc Van Der Lee

Ulrich Weichmann

Mark Carpaij

Marcel Franz Christian Schemmann

Robert Weiss

Michael Miller

Matthias Falk

Rico Srowik

Rainer Michalzik

Sven Bader

Holger M Moench

Hans Spruit

Roland Aloisius Jaeger

Christian Wimmer

Alexander Van Der Lee

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 InGaAs layer, where 0≤x<1. The light absorption region has an InGaAs layer, where 0<y<1, and y>x. The InGaAs layer is an intrinsic layer of the light absorption region. The InGaAs layer is 15-50 nm thick. The light absorption region has an undoped layer with a material different from the InGaAs layer. The InGaAs layer is immediately adjacent to the undoped layer. An intrinsic zone of the light absorption region is at least 70 nm thick.

Vertical cavity surface emitting laser device with monolithically integrated photodiode

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 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.

Vertical cavity surface emitting laser device with integrated photodiode

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.

Laser device and method of determining a malfunction of a laser diode

A Vertical Cavity Surface Emitting Laser (VCSEL) includes a VCSEL array, a multitude of detectors, a first electrical laser contact, and at least one second electrical laser contact. The VCSEL array comprises a multitude of laser diodes, each laser diode including an optical resonator having a first distributed Bragg reflector, a second distributed Bragg reflector and an active layer for light emission, the active layer being arranged between the first distributed Bragg reflector and the second distributed Bragg reflector. The first electrical laser contact and the at least one second electrical laser contact are arranged to provide an electrical drive current to electrically pump the optical resonators of the laser diodes. Each detector is arranged to generate an electrical self-mixing interference measurement signal associated to at least one laser diode upon reception of the laser light.

VCSEL device for an SMI sensor for recording three-dimensional pictures

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).

Method and apparatus for monitoring the optical output power of a laser diode with an associated photodiode and particle sensor device

A vertical cavity surface emitting laser (VCSEL) has first and second electrical contacts, and an optical resonator. The optical resonator has first and second distributed Bragg reflectors (DBRs), an active layer, a distributed heterojunction bipolar phototransistor (DHBP), and an optical guide. The DHBP has a collector layer, light sensitive layer; a base layer; and an emitter layer. There is an optical coupling between the active layer and the DHBP for providing an active carrier confinement by the DHBP. The optical guide guides an optical mode within the optical resonator during operation. The optical guide is outside a current flow which can be provided by the first and second electrical contacts during operation of the VCSEL. The optical guide is outside a layer sequence between the first and second electrical contacts in the vertical direction of the VCSEL. The optical guide has an oxide aperture arranged in the second DBR.

Vertical cavity surface emitting laser

The present invention provides a method for estimating a condition parameter of a laser diode having an associated photodiode, to an apparatus for monitoring the operation of such a laser diode, and to 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). The at least one condition parameter is estimated during the operation of the laser diode (LD) and the estimation is based on current measurements and/or voltage measurements at the laser diode (LD) and/or at the photodiode (PD).

Method of estimating a condition parameter of a laser diode with an associated photodiode, apparatus for monitoring the operation of such laser diode and particular sensor apparatus

The invention describes a laser device comprising between two and six mesas () provided on one semiconductor chip (), wherein the mesas () are electrically connected in parallel such that the mesas () are adapted to emit laser light if a defined threshold voltage is provided to the mesas (). Two to six mesas () with reduced active diameter in comparison to a laser device with one mesa improve the yield and performance despite of the fact that two to six mesas need more area on the semiconductor chip thus increasing the total size of the semiconductor chip (). The invention further describes a method of marking semiconductor chips (). A functional layer of the semiconductor chip () is provided and structured in a way that a single semiconductor chip () can be uniquely identified by means of optical detection of the structured functional layer. The structured layer enables identification of small semiconductor chips () with a size below 200 &#x3bc;m&#xd7;200 &#x3bc;m.

Compact laser device

The disclosure relates to a Vertical Cavity Surface Emitting Laser () comprising a first electrical contact (), a substrate (), a first Distributed Bragg Reflector (), an active layer (), a second Distributed Bragg Reflector () and a second electrical contact (). The Vertical Cavity Surface Emitting Laser comprises at least two current aperture layers () arranged below or above the active layer (), wherein each of the current aperture layers () comprises one AlGaAs-layer, wherein a first current aperture layer () of the at least two current aperture layers () is arranged nearer to the active layer () as a second current aperture layer () of the at least two current aperture layers (), wherein the first current aperture layer () comprises a first current aperture () with a bigger size as a second current aperture () of the second current aperture layer (). The disclosure also relates to a method of manufacturing such a VCSEL ().

The invention describes a laser device () comprising between two and six mesas () provided on one semiconductor chip (), wherein the mesas () are electrically connected in parallel. The laser device () is adapted such that degradation of at least one mesa () results in a decreased laser power emitted by the laser device () in a defined solid angle when driven at the defined electrical input power. The laser device () is adapted such that eye safety of the laser device () is guaranteed during life time of the laser device (). Eye safety may be guaranteed by designing the semiconductor structure or more general layer structure of mesas () of the laser device () in a way that degradation of one or more layers of the layer structure results in a reduction of the maximum optical power emitted in a defined solid angle. Alternatively or in addition, the electrical input power supplied to the laser device () may be controlled and adapted depending on the emitted optical power such that safety limits are not exceeded. The invention further relates to a laser module and an optical sensor () comprising such a laser device () and mobile communication device () comprising such an optical sensor (). The invention further relates to a method of manufacturing such a laser device ().

Safe laser device for optical sensing applications

The invention relates to a Vertical Cavity Surface Emitting Laser () comprising a first electrical contact (), a substrate (), a first Distributed Bragg Reflector (), an active layer (), a second Distributed Bragg Reflector () and a second electrical contact (). The Vertical Cavity Surface Emitting Laser comprises at least one AlGaAs-layer with 0.95&#x2264;y&#x2264;1 with a thickness of at least 40 nm, wherein the AlGaAs-layer is separated by means of at least one oxidation control layer (). The invention further relates to a laser device () comprising such a VCSEL () preferably an array of such a VCSELs () which are driven by an electrical driving circuit (). The invention also relates to a method of manufacturing such a VCSEL ().

The invention describes a Vertical Cavity Surface Emitting Laser and a method of manufacturing such a Vertical Cavity Surface Emitting Laser. The Vertical Cavity Surface Emitting Laser comprising a first electrical contact (), a substrate (), a first distributed Bragg reflector (), an active layer (), a distributed heterojunction bipolar phototransistor (), a second distributed Bragg reflector () and a second electrical contact (), the distributed heterojunction bipolar phototransistor () comprising a collector layer (), a light sensitive layer (), a base layer () and an emitter layer (), wherein the distributed heterojunction bipolar phototransistor () is arranged such that there is an optical coupling between the active layer () and the distributed heterojunction bipolar phototransistor () for providing an active carrier confinement by means of the distributed heterojunction bipolar phototransistor () such that an optical mode of the Vertical Cavity Surface Emitting Laser is self-positioning in accordance with the active carrier confinement during operation of the Vertical Cavity Surface Emitting Laser. It is the intention of the present invention to provide a VCSEL which can be easily and reliably processed by integrating the distributed heterojunction bipolar phototransistor ().

The present invention relates to a laser device being formed of at least one VCSEL () with intracavity contacts. The VCSEL comprises a layer structure () with an active region () between a first DBR () and a second DBR (), a first current-injection layer () of a first conductivity type between the first DBR () and the active region (), and a second current-injection layer () of a second conductivity type between the second DBR () and the active region (). The first and second current-injection layers () are in contact with a first and a second metallic contact (), respectively. The first and/or second DBR () are formed of alternating Aluminum oxide and Al(x)Ga(1&#x2212;x)As containing layers. The proposed design of this VCSEL allows an increased efficiency and lower production costs of such a laser since the top and bottom DBRs may be formed of a considerable reduced thickness.

Growing community of inventors

Blaustein, Germany

Philipp Henning Gerlach