Abstract: Single-mode quantum cascade semiconductor lasers are provided. The lasers comprise a laser element, the laser element comprising a quantum cascade active layer; an upper cladding layer over the quantum cascade active layer; and a lower cladding layer under the quantum cascade active layer, wherein the quantum cascade active layer, the upper cladding layer and the lower cladding layer define a guided optical mode. The quantum cascade active layer and the upper and lower cladding layers are shaped in the form of a ridge structure having a front face, a back face opposite the front face, and a lasing face through which laser emission exits the ridge structure, the ridge structure configured such that the laser emission has a single-lobe, far-field beam pattern from the ridge structure comprising certain sections, including tapered sections, collateral sections, or both.

Abstract: A ventilation device for a cabin of a vehicle, the ventilation device includes a temperature-control circuit in which a fluid circulates for heat transfer; an ambient heat exchanger via which heat is exchanged between the temperature-control circuit and a cabin environment; a cabin heat exchanger via which heat is exchanged between the temperature-control circuit and an air flow provided for ventilating the cabin; one or more liquid channels connecting the ambient heat exchanger to the cabin heat exchanger; an air supply system for directing air to the cabin heat exchanger to supply the passengers in the cabin, and an air conveyor device for conveying supply air; and a distance between the air conveyor device and the passenger is greater than a distance between the cabin heat exchanger and the passenger.

Abstract: A fluid distribution device that includes a distributor housing having at least one fluid inlet opening and at least one fluid outlet opening; and at least one rotary, elongated hollow element having a wall that has one or more fluid-passage openings, a fluid flow through the distributor housing is changed by rotating the at least one hollow element.

Abstract: An air temperature-controllable module, for a temperature-controllable storage unit, having an air temperature-controllable unit including a useful air temperature-controllable region, a waste air temperature-controllable region, and at least one thermoelectric device including a useful air side and a waste air side, the useful air side connected to the useful air temperature-controllable region and the waste air side connected to the waste air temperature-controllable region, a useful air path for a useful air flow extending from a useful air inlet to a useful air outlet and the useful air temperature-controllable region of the air temperature-controllable unit connecting to the useful air outlet, and a waste air path for a waste air flow extending from a waste air inlet to a waste air outlet and connecting the waste air temperature-controllable region of the air temperature-controllable unit to the waste air outlet.

Abstract: A terahertz quantum cascade laser device is provided comprising a substrate having a top substrate surface, a bottom substrate surface, and an exit facet extending between the top substrate surface and the bottom substrate surface at an angle ?tap. The device comprises a waveguide structure having a top surface, a bottom surface, a front facet extending between the top surface and the bottom surface and positioned proximate to the exit facet, and a back facet extending between the top surface and the bottom surface and oppositely facing the front facet. The waveguide structure comprises a quantum cascade laser structure configured to generate light comprising light of a first frequency ?1, light of a second frequency ?2, and light of a third frequency ?THz, wherein ?THz=?1??2; an upper cladding layer; and a lower cladding layer.

Abstract: Methods for the fabrication of orientation-patterned semiconductor structures are provided. The structures are light-waveguiding structures for nonlinear frequency conversion. The structures are periodically poled semiconductor heterostructures comprising a series of material domains disposed in a periodically alternating arrangement along the optical propagation axis of the waveguide. The methods of fabricating the orientation-patterned structures utilize a series of surface planarization steps at intermediate stages of the heterostucture growth process to provide interlayer interfaces having extremely low roughnesses.

Abstract: Methods for the fabrication of orientation-patterned semiconductor structures are provided. The structures are light-waveguiding structures for nonlinear frequency conversion. The structures are periodically poled semiconductor heterostructures comprising a series of material domains disposed in a periodically alternating arrangement along the optical propagation axis of the waveguide. The methods of fabricating the orientation-patterned structures utilize a series of surface planarization steps at intermediate stages of the heterostucture growth process to provide interlayer interfaces having extremely low roughnesses.

Abstract: Methods for the fabrication of orientation-patterned semiconductor structures are provided. The structures are light-waveguiding structures for nonlinear frequency conversion. The structures are periodically poled semiconductor heterostructures comprising a series of material domains disposed in a periodically alternating arrangement along the optical propagation axis of the waveguide. The methods of fabricating the orientation-patterned structures utilize a series of surface planarization steps at intermediate stages of the heterostructure growth process to provide interlayer interfaces having extremely low roughnesses.

Abstract: Semiconductor lasers comprise a substrate; an active layer configured to generate transverse magnetic (TM) polarized light under an electrical bias; an upper cladding layer; a lower cladding layer; and a distributed feedback (DFB) grating defined by the interface of a layer of metal and a layer of semiconductor under the layer of metal, the interface periodically corrugated in the longitudinal direction of the laser with a periodicity of ?DFB=m?/(2neff), wherein m>1. The DFB grating is configured such that loss of one or more antisymmetric longitudinal modes of the laser structure via absorption to the DFB grating is sufficiently maximized so as to produce lasing of a symmetric longitudinal mode of the laser with laser emission characterized by a single-lobe beam along each direction defined by the grating diffraction orders corresponding to emission away from the plane of the grating.

Abstract: Semiconductor lasers comprise a substrate; an active layer configured to generate transverse magnetic (TM) polarized light under an electrical bias; an upper cladding layer; a lower cladding layer; and a distributed feedback (DFB) grating defined by the interface of a layer of metal and a layer of semiconductor under the layer of metal, the interface periodically corrugated in the longitudinal direction of the laser with a periodicity of ?DFB=m?/(2neff), wherein m>1. The DFB grating is configured such that loss of one or more antisymmetric longitudinal modes of the laser structure via absorption to the DFB grating is sufficiently maximized so as to produce lasing of a symmetric longitudinal mode of the laser with laser emission characterized by a single-lobe beam along each direction defined by the grating diffraction orders corresponding to emission away from the plane of the grating.

Abstract: A self-locking switch including a button sub-assembly and a housing sub-assembly. The button sub-assembly includes at least one button with a tab extending from a lower surface at a first end and at least one shaft engagement point on the lower surface at a second end, and a bracket comprising a first end and a second end with a rotation shaft at the second end. The bracket is rotatably connected to the button. The housing sub-assembly includes a switch housing having engagement points, and a switching mechanism in the housing. The button sub-assembly and the housing sub-assembly are joined together by engaging the tab of the button and the first and second ends of the bracket to corresponding engagement points on the switch housing and the engagement points are not accessible from outside the self-locking switch after the button sub-assembly and the housing sub-assembly are assembled together.

Abstract: Semiconductor structures for laser devices are provided. The semiconductor structures have a quantum cascade laser structure comprising an electron injector, an active region, and an electron extractor. The active region comprises an injection barrier, a multiquantum well structure, and an exit barrier. The multiquantum well structure can comprise a first barrier, a first quantum well, a second barrier, a second quantum well, and a third barrier. The energies of the first and second barrier are less than the energy of the third barrier. The energy difference between the energy of the second barrier and the energy of the third barrier can be greater than 150 meV and the ratio of the energy of the third barrier to the energy of the second barrier can be greater than 1.26.

Abstract: Semiconductor structures for laser devices are provided. The semiconductor structures have a quantum cascade laser structure comprising an electron injector, an active region, and an electron extractor. The active region comprises an injection barrier, a multiquantum well structure, and an exit barrier. The multiquantum well structure can comprise a first barrier, a first quantum well, a second barrier, a second quantum well, and a third barrier. The energies of the first and second barrier are less than the energy of the third barrier. The energy difference between the energy of the second barrier and the energy of the third barrier can be greater than 150 meV and the ratio of the energy of the third barrier to the energy of the second barrier can be greater than 1.26.

Abstract: Methods for the fabrication of orientation-patterned semiconductor structures are provided. The structures are light-waveguiding structures for nonlinear frequency conversion. The structures are periodically poled semiconductor heterostructures comprising a series of material domains disposed in a periodically alternating arrangement along the optical propagation axis of the waveguide. The methods of fabricating the orientation-patterned structures utilize a series of surface planarization steps at intermediate stages of the heterostructure growth process to provide interlayer interfaces having extremely low roughnesses.

Abstract: A self-locking switch including a button sub-assembly and a housing sub-assembly. The button sub-assembly includes at least one button with a tab extending from a lower surface at a first end and at least one shaft engagement point on the lower surface at a second end, and a bracket comprising a first end and a second end with a rotation shaft at the second end. The bracket is rotatably connected to the button. The housing sub-assembly includes a switch housing having engagement points, and a switching mechanism in the housing. The button sub-assembly and the housing sub-assembly are joined together by engaging the tab of the button and the first and second ends of the bracket to corresponding engagement points on the switch housing and the engagement points are not accessible from outside the self-locking switch after the button sub-assembly and the housing sub-assembly are assembled together.

Abstract: Semiconductor laser array devices capable of emitting mid- to long-wavelength infrared (i.e., 4-12 ?m) radiation are provided. The devices include a quantum cascade laser (QCL) structure comprising one or more active cores; an optical confinement structure; a cladding structure, and a plurality of laterally-spaced trench regions extending transversely through the cladding and optical confinement structures, and partially into the QCL structure. The trench regions define a plurality of laterally-spaced interelement regions separated by element regions in the laser array device. The element regions are characterized by a non-uniform structure across their widths. As a result of this structural non-uniformity, array modes composed of coupled first-order lateral modes of the element regions are preferentially suppressed relative to array modes composed of coupled fundamental lateral modes of the element regions.

Abstract: Semiconductor structures and laser devices including the semiconductor structures are provided. The semiconductor structures have a quantum cascade laser (QCL) structure including an electron injector, an active region, and an electron extractor. The active region of the semiconductor structures includes a configuration of quantum wells and barriers that virtually suppresses electron leakage, thereby providing laser devices including such structures with superior electro-optical characteristics.

Abstract: Semiconductor laser array devices capable of emitting mid- to long-wavelength infrared (i.e., 4-12 ?m) radiation are provided. The devices include a quantum cascade laser (QCL) structure comprising one or more active cores; an optical confinement structure; a cladding structure, and a plurality of laterally-spaced trench regions extending transversely through the cladding and optical confinement structures, and partially into the QCL structure. The trench regions define a plurality of laterally-spaced interelement regions separated by element regions in the laser array device. The element regions are characterized by a non-uniform structure across their widths. As a result of this structural non-uniformity, array modes composed of coupled first-order lateral modes of the element regions are preferentially suppressed relative to array modes composed of coupled fundamental lateral modes of the element regions.

Abstract: Semiconductor laser array devices capable of emitting mid- to long-wavelength infrared (i.e., 4-12 ?m) radiation are provided. The devices include a quantum cascade laser (QCL) structure comprising one or more active cores; an optical confinement structure; a cladding structure; and a plurality of laterally-spaced trench regions extending transversely through the optical confinement and cladding structures, and partially into the QCL structure. The trench regions, each of which comprises a lower trench layer comprising a semi-insulating material and an upper trench layer comprising a material having a refractive index that is higher than that of the semi-insulating material, define a plurality of laterally-spaced interelement regions separated by element regions in the laser array device.

Abstract: Semiconductor laser array devices capable of emitting mid- to long-wavelength infrared (i.e., 4-12 ?m) radiation are provided. The devices include a quantum cascade laser (QCL) structure comprising one or more active cores; an optical confinement structure; a cladding structure; and a plurality of laterally-spaced trench regions extending transversely through the optical confinement and cladding structures, and partially into the QCL structure. The trench regions, each of which comprises a lower trench layer comprising a semi-insulating material and an upper trench layer comprising a material having a refractive index that is higher than that of the semi-insulating material, define a plurality of laterally-spaced interelement regions separated by element regions in the laser array device.