Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.

An edge-emitting semiconductor laser and a method for operating a semiconductor laser are disclosed. In an embodiment, the edge-emitting semiconductor laser includes an active zone within a semiconductor layer sequence and a stress layer. The active zone is configured for being energized only in a longitudinal strip perpendicular to a growth direction of the semiconductor layer sequence. The semiconductor layer sequence has a constant thickness throughout in the region of the longitudinal strip so that the semiconductor laser is gain-guided. The stress layer may locally stress the semiconductor layer sequence in a direction perpendicular to the longitudinal strip and in a direction perpendicular to the growth direction. A refractive index of the semiconductor layer sequence, in regions which, seen in plan view, are located next to the longitudinal strip, for the laser radiation generated during operation is reduced by at least 2×10.sup.−4 and by at most 5×10.sup.−3.

Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.

Systems and methods described herein may include a first semiconductor layer with a first lattice constant, a rare earth pnictide buffer epitaxially grown over the first semiconductor, wherein a first region of the rare earth pnictide buffer adjacent to the first semiconductor has a net strain that is less than 1%, a second semiconductor layer epitaxially grown over the rare earth pnictide buffer, wherein a second region of the rare earth pnictide buffer adjacent to the second semiconductor has a net strain that is a desired strain, and wherein the rare earth pnictide buffer may comprise one or more rare earth elements and one or more Group V elements. In some examples, the desired strain is approximately zero.

A Schottky diode is monolithically integrated into the core of an infrared semiconductor laser (e.g., a quantum cascade laser) to create a heterodyned infrared transceiver. The internal mode field of the infrared semiconductor laser couples to an embedded Schottky diode and can mix the infrared fields to generate a response at the difference frequency.

A laser emitter is provided, including a substrate and a dielectric mask layer located proximate to and above the substrate in a thickness direction. The dielectric mask layer may have a plurality of trenches formed therein. The plurality of trenches may have a plurality of different respective widths. The laser emitter may further include a respective nanowire located within each trench of the plurality of trenches. Each nanowire may include a first semiconductor layer located above the substrate in the thickness direction. Each nanowire may further include a quantum well layer located proximate to and above the first semiconductor layer in the thickness direction. Each nanowire may further include a second semiconductor layer located proximate to and above the quantum well layer in the thickness direction.

Building blocks are provided for on-chip chemical sensors and other highly-compact photonic integrated circuits combining interband or quantum cascade lasers and detectors with passive waveguides and other components integrated on a III-V or silicon. A MWIR or LWIR laser source is evanescently coupled into a passive extended or resonant-cavity waveguide that provides evanescent coupling to a sample gas (or liquid) for spectroscopic chemical sensing. In the case of an ICL, the uppermost layer of this passive waveguide has a relatively high index of refraction that enables it to form the core of the waveguide, while the ambient air, consisting of the sample gas, functions as the top cladding layer. A fraction of the propagating light beam is absorbed by the sample gas if it contains a chemical species having a fingerprint absorption feature within the spectral linewidth of the laser emission.

The invention relates to a semiconductor laser comprising a layer structure comprising an active zone, wherein the active zone is configured to generate an electromagnetic radiation, wherein the layer structure comprises a sequence of layers, wherein two opposite end faces are provided in a Z-direction, wherein at least one end face is configured to at least partly couple out the electromagnetic radiation, and wherein the second end face is configured to at least partly reflect the electromagnetic radiation, wherein guide means are provided for forming an optical mode in a mode space between the end faces, wherein means are provided which hinder a formation of an optical mode outside the mode space, in particular modes comprising a propagation direction which do not extend perpendicularly to the end faces.

A pixel structure for a vertical cavity surface emitting laser has an emission window. The pixel structure includes a plurality of sub-pixels in the emission window. Bright-area sub-pixels emit light and dark-area sub-pixels having no light emission. The bright-area sub-pixels and the dark-area sub-pixels are arranged in a pattern in the emission window. Various patterns are possible. Different structures for implementing the sub-pixels are described.

A laser emitter is provided, including a substrate and a dielectric mask layer located proximate to and above the substrate in a thickness direction. The dielectric mask layer may have a plurality of trenches formed therein. The plurality of trenches may have a plurality of different respective widths. The laser emitter may further include a respective nanowire located within each trench of the plurality of trenches. Each nanowire may include a first semiconductor layer located above the substrate in the thickness direction. Each nanowire may further include a quantum well layer located proximate to and above the first semiconductor layer in the thickness direction. Each nanowire may further include a second semiconductor layer located proximate to and above the quantum well layer in the thickness direction.