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.

A laser device includes a plurality of laser diodes that generate laser light beams having different wavelengths from each other, a partial reflective mirror constituting a resonator along with the laser diodes, a wavelength dispersive element set in the resonator, which combines parts of the laser light beams outputted by the laser diodes to each other, emits the combined parts of the laser light beams as a first laser light beam toward the partial reflective mirror, and emits other parts of the laser light beams as second laser light beams in directions different from the direction toward the partial reflective mirror, and an output detecting unit detecting intensities of the second laser light beams.

A laser diode includes a semiconductor structure having an n-type layer, an active region, and a p-type layer. One of the n-type and p-type layers includes a lasing aperture thereon having an optical axis oriented perpendicular to a surface of the active region between the n-type and p-type layers. First and second contacts are electrically connected to the n-type and p-type layers, respectively. The first and/or second contacts are smaller than the lasing aperture in at least one dimension. Related arrays and methods of fabrication are also discussed.

A laser device includes a plurality of laser diodes that generate laser light beams having different wavelengths from each other, a partial reflective mirror constituting a resonator along with the laser diodes, a wavelength dispersive element set in the resonator, which combines parts of the laser light beams outputted by the laser diodes to each other, emits the combined parts of the laser light beams as a first laser light beam toward the partial reflective mirror, and emits other parts of the laser light beams as second laser light beams in directions different from the direction toward the partial reflective mirror, and an output detecting unit detecting intensities of the second laser light beams.

A laser array includes a plurality of laser emitters arranged in a plurality of rows and a plurality of columns on a substrate that is non-native to the plurality of laser emitters, and a plurality of driver transistors on the substrate adjacent one or more of the laser diodes. A subset of the plurality of laser emitters includes a string of laser emitters that are connected such that an anode of at least one laser emitter of the subset is connected to a cathode of an adjacent laser emitter of the subset. A driver transistor of the plurality of driver transistors is configured to control a current flowing through the string.

A laser diode includes a semiconductor structure having an n-type layer, an active region, and a p-type layer. One of the n-type and p-type layers includes a lasing aperture thereon having an optical axis oriented perpendicular to a surface of the active region between the n-type and p-type layers. First and second contacts are electrically connected to the n-type and p-type layers, respectively. The first and/or second contacts are smaller than the lasing aperture in at least one dimension. Related arrays and methods of fabrication are also discussed.

The invention describes a laser sensor module. The laser sensor module comprises at least a first laser (111) being adapted to emit a first measurement beam (111) and at least a second laser (112) being adapted to emit a second measurement beam (112). The laser sensor module further comprises an optical device (150) being arranged to redirect the first measurement beam (111) and the second measurement beam (112) such that the 5 first measurement beam (111) and the second measurement beam enclose an angle between 45 and 135. The laser sensor module comprises one detector (120) 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 (111) and at least a second self-mixing interference signal of a second optical wave within a second laser cavity of the second laser (112). This configuration 10 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 (100) comprising such a laser sensor module, a corresponding method and computer program 15 product. The invention enables a simple and low-cost particle sensor (100) for detecting small particles based on laser self-mixing interference.

A detector is for identifying chemicals in a sample. The detector may include a photodetector comprising SiC semiconductor material and configured to have an acceptor energy band of range E.sub.aE.sub.a to E.sub.a+E.sub.a. The SiC semiconductor material may be doped with a dopant to exceed a threshold dopant concentration level. The photodetector may be configured to receive fluorescence information from the sample.

An optical proximity sensor includes a first vertical cavity surface-emitting laser configured for self-mixing interferometry to determine distance to and/or velocity of an object. The optical proximity sensor also includes a second vertical cavity surface-emitting laser configured for self-mixing interferometry to determine whether any variation in a fixed distance has occurred. The optical proximity sensor leverages output from the second vertical cavity surface-emitting laser to calibrate output from the second vertical cavity surface-emitting laser to eliminate and/or mitigate environmental effects, such as temperature changes.

A device has a laser unit, which includes: a top-side p-type DBR region; which is on top of and in direct touch with an active region; which is on top of and in direct touch with a bottom-side n-type Distributed Bragg Reflector (DBR) region; which is on top of a n-type substrate. The laser unit further includes a voltage measurement anode touching or being in proximity to a top surface of the active region; and a voltage measurement cathode touching or being in proximity to a bottom surface of the active region. The voltage between the voltage measurement anode and the voltage measurement cathode is directly measured; and is utilized for determining characteristics of a laser self-mix signal of the laser unit, without having or using a monitor photo-diode.