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)λ/(4 m). Where λ is the wavelength of the laser light in the absorption region, and k and m are natural numbers≥1.

An optical semiconductor integrated element comprises a laser section and a photodetector section which are arranged on the same semiconductor substrate, the laser section and the photodetector section each have a light confining layer which confines light, a cladding layer, and a contact layer formed of an InGaAs layer or an InGaAsP layer, the light confining layer of the laser section is an active layer, the contact layer of the photodetector section is a light absorption layer, each cladding layer is a ridge structure having a shape in which a width at a side of the light confining layer is narrower than a width at a side of the contact layer in a cross-section which is perpendicular to the optical axis, and on a side surface of the light confining layer, the cladding layer and the contact layer, a semiconductor embedded layer is not provided.

Electro-absorption modulators (EAM) and monolithically integrated electro-absorption modulated lasers (EML) and methods of fabrication are disclosed. Vertically stacked waveguides for a distributed feedback (DFB) laser, an electro-absorption modulator (EAM) and a passive output waveguide are vertically integrated, and the DFB laser, EAM and output waveguide are optically coupled using laterally tapered vertical optical couplers. Laterally tapered vertical optical couplers provides an alternative to conventional butt-coupling of a laser and EAM, offering improved reliability for high power operation over extended lifetimes. Optionally, the EML comprises monolithically integrated electronic circuitry, e.g., driver and control electronics for the DFB laser and EAM. Beneficially, integrated EAM driver and control circuitry comprises a high-speed electro-optical control loop for very high-speed linearization and temperature compensation, e.g. to enable advanced modulation schemes, such as PAM-4 and DP-QPSK, for analog optical data center interconnect applications. Some embodiments are compatible with fabrication using a single epitaxial growth.

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.

An optical multiplexing circuit capable of accurately monitoring light of a plurality of wavelengths is provided. An optical multiplexing circuit includes a plurality of branching units configured to each divide light output from a corresponding one of a plurality of input waveguides, a multiplexing unit configured to multiplex a plurality of first beams of the light, each obtained by dividing the light by a corresponding one of the plurality of branching units, an output waveguide configured to output the light multiplexed by the multiplexing unit, a plurality of monitoring multiplexing units that are optical circuits identical to the multiplexing unit, a plurality of first monitoring waveguides configured to output a plurality of second beams of the light, each obtained by dividing the light by a corresponding one of the plurality of branching units, to corresponding ones of the plurality of monitoring multiplexing units, and a plurality of second monitoring waveguides configured to each output an output of a corresponding one of the plurality of monitoring multiplexing units.

A sensor system includes a self-mixing interferometry sensor; a drive circuit configured to apply a modulated drive signal to an input of the self-mixing interferometry sensor; a mixer circuit configured to mix a modulated output of the self-mixing interferometry sensor with a local oscillator signal that is orthogonal to the modulated drive signal over a period of time; an integrator circuit configured to integrate an output of the mixer circuit over the period of time; and a processor configured to determine, using an output of the integrator circuit, at least one of a round-trip propagation time of electromagnetic radiation emitted by the self-mixing interferometry sensor and reflected back into the self-mixing interferometry sensor by an object or medium, or a velocity of the object or medium.

The invention relates to a radiation-emitting semiconductor chip having the following features:—a semiconductor body including an active region which, during operation, generates electromagnetic radiation and is arranged in a resonator, —at least one recess in the semiconductor body, which recess completely penetrates the active region, wherein—the recess has a first lateral face and a second lateral face opposite the first lateral face, and—the first lateral face has a first coating which specifies a reflectivity for the electromagnetic radiation of the active region, and/or—the second lateral face has a second coating which specifies a reflectivity for the electromagnetic radiation of the active region. The invention further relates to a method for producing such a semiconductor chip.

An optoelectronic device includes a semiconductor substrate and a first stack of epitaxial layers, which are disposed over the semiconductor substrate and are configured to function as a photodetector, which emits a photocurrent in response to infrared radiation in a range of wavelengths greater than 940 nm. A second stack of epitaxial layers is disposed over the first stack and configured to function as an optical transmitter with an emission wavelength in the range of wavelengths greater than 940 nm.

To enable downsizing and prevent an adverse effect on distance measurement.

A surface emitting laser device includes a surface emitting section having a plurality of light emitting elements arranged on a substrate, and some of the plurality of light emitting elements are used as light receiving elements.

A wideband electro-absorption modulating (EAM) device is configured to include a ground shield that functions to minimize the spread of an applied AC voltage beyond the limits of the modulator's electrode. The ground shield includes a grounding electrode disposed in a spaced-apart relationship with the modulator electrode along the ridge of the EAM structure, and a grounding termination used to couple the grounding electrode to a suitable ground location. The ground location may be either on-chip (such as the DC ground of the modulator itself) or off-chip (via an off-chip capacitor, with a wirebond connecting the grounding electrode to the capacitor). The use of a ground shield mitigates the effects that changes in the data rate have on effective length of the modulator as seen by the applied data signal.