64 results about "Quantum cascade laser" patented technology

The invention discloses an on-line detection method for volatile organic compounds in waste gas, and belongs to the field of waste gas emission monitoring, the detection method comprises the following specific steps: I, starting a quantum cascade laser frequency comb of a middle infrared band, calibrating various parameters of the quantum cascade laser frequency comb, and ensuring to cover a characteristic absorption area of the volatile organic compounds in the waste gas; iI, inputting the waste gas into a gas detection chamber through a sampling pipeline, monitoring the state of the waste gas in real time, and dynamically adjusting the conditions of the gas detection chamber according to various collected signals; the device can capture instantaneous fluctuation of waste gas concentration in real time, meets the high-speed dynamic emission monitoring requirement, has extremely high coherence and narrow linewidth, can analyze tiny spectral line differences which cannot be distinguished by a traditional spectrograph, remarkably improves the detection precision and the recognition capability, ensures that a measurement result still keeps consistency and high reliability under different working conditions, and is suitable for large-scale popularization and application. The signal-to-noise ratio is obviously improved, the power drift is reduced, and long-time stable operation is realized.

A quantum-cascade laser element includes: a semiconductor substrate; a semiconductor mesa formed on the semiconductor substrate to include an active layer having a quantum-cascade structure and to extend along a light waveguide direction; an embedding layer formed to interpose the semiconductor mesa along a width direction of the semiconductor substrate; a cladding layer formed over the semiconductor mesa and over the embedding layer; and a metal layer formed on the cladding layer. A pair of groove portions extending along the light waveguide direction are formed in a surface on an opposite side of the cladding layer from the semiconductor substrate. The pair of groove portions are disposed in two respective outer regions when the cladding layer is equally divided into four regions in the width direction of the semiconductor substrate. The metal layer enters the pair of groove portions.

The invention relates to a quantum cascade laser emitting a polarized TM optical mode with a wavelength between 3 and 15 µm, comprising an amplifying medium and a main waveguide. The latter includes a coupling section in contact with the amplifying medium, comprising a diffraction grating (DFB). The coupling section has a width greater than or equal to a minimum width from which an antisymmetric supermode propagating in a laser guidance structure comprising the amplifying medium and the main waveguide has a confinement factor in an active region of the amplifying medium strictly greater than those of the optical modes capable of being guided by the guidance structure. The main waveguide comprises a core based on atoms from column IVA of the periodic table of elements and a confinement subshell of SiN or a chalcogenide. (See Figure 1A for the abstract.)

The invention discloses an annular micro-cavity quantum cascade laser. The laser comprises substrates which are sequentially arranged from bottom to top; the annular microcavity is arranged on the substrate, the annular microcavity is an elliptical resonator with a notch, and a groove is formed in the central area of the annular microcavity; the semi-insulating InP: Fe filling layer is arranged in the groove in the central area of the annular microcavity, and the difference between the resistivity of the semi-insulating InP: Fe filling layer and the refractive index of the upper cladding and the contact layer is less than 1%; the supporting ridges are arranged on the substrate, and the two supporting ridges are arranged on the two sides of the annular microcavity and are as high as the annular microcavity; the coplanar electrode comprises a central electrode arranged on the upper surface of the annular microcavity and grounding electrodes symmetrically arranged on the outer surface of the supporting ridge structure, and the central electrode and the grounding electrodes are the same in height. The quantum cascade laser has high-frequency modulation performance, improves heat dissipation performance, and has high response rate.

A quantum cascade laser element includes: a semiconductor substrate; a semiconductor laminate including an active layer and having a first end surface and a second end surface facing each other in an optical waveguide direction; a first electrode; a second electrode; and an anti-reflection film formed on the first end surface. The semiconductor laminate is configured to oscillate laser light having a central wavelength of 7.5 μm or more. The anti-reflection film includes at least one of at least one layer of a CeO2 film formed by continuous sputtering and vacuum evaporation and a plurality of layers of CeO2 films formed by discrete sputtering and vacuum evaporation.

The laser module includes a QCL element, a diffraction grating unit, a first lens holder, a second lens holder, and a mount member. The first mounting portion has a first top surface on which the first lens holder is mounted via an adhesive layer. The third mounting portion has a third top surface on which the second lens holder is mounted via an adhesive layer. The second mounting portion has a second top surface located higher than the first top surface and the third top surface, a first side surface connecting the second top surface and the first top surface, and a second side surface connecting the second top surface and the third top surface. A notch extending from the second top surface to the first top surface or the third top surface is formed in at least one of the first side surface and the second side surface.

This invention discloses a quantum cascade laser and its fabrication method, relating to the field of laser technology. The quantum cascade laser includes a substrate layer; a lower waveguide layer located on the substrate layer; an active layer located on the lower waveguide layer and including multiple injection layers located on the lower waveguide layer; and multiple light-emitting layers, wherein electrons in the light-emitting layers transition from high energy levels to low energy levels, suitable for exciting electrons to generate excitation light; wherein the light-emitting layers and injection layers are periodically stacked in an alternating cascade structure, each injection layer extracts low-energy electrons from the adjacent light-emitting layer above the injection layer and transports the low-energy electrons to the light-emitting layer of the previous period adjacent to the injection layer to form high-energy electrons, thereby transporting electrons between light-emitting layers belonging to two adjacent periods; and an upper waveguide layer located on the light-emitting layers, which can achieve a highly concentrated number of high-energy electrons, thereby realizing a large-scale, high-power quantum cascade laser.

An analysis device includes a substrate including a first surface, and a second surface positioned at a side opposite to the first surface; a light source part located at the first surface of the substrate, the light source part including a quantum cascade laser; a light detector located at the first surface of the substrate; and a wiring part located at the first surface of the substrate, the wiring part being electrically connected with the light source part and the light detector.

The application discloses an anti-interface rough scattering quantum cascade laser active region and a preparation method thereof. The application forms a topological interface state protected by chiral symmetry as a lasing upper energy level at the butt joint interface between a first superlattice region and a second superlattice region, the wave function of the topological interface state is strictly zero in the thick barrier center and the interface, thereby the non-radiation loss caused by the interface roughness scattering is inhibited from the root, and the upper energy level carrier lifetime is significantly prolonged. Based on this, the threshold current density of the quantum cascade laser is greatly reduced, and high-efficiency lasing of 10 μm wavelength can be realized at room temperature. Meanwhile, a mixed epitaxy process combining molecular beam epitaxy and metal organic chemical vapor deposition is adopted, the nanometer precision energy band design of the core active region is ensured, and the efficient growth of the thick film waveguide layer is realized, which is beneficial to the practicalization and large-scale preparation of the device.

The application discloses a kind of quantum cascade laser light frequency comb based on on-chip dispersion regulation and preparation method thereof, comprising: sequentially growing lower waveguide layer, passive waveguide layer, low-doped waveguide layer, high-doped waveguide layer, lower limiting layer, active region, upper limiting layer, upper waveguide layer, ohmic contact layer on substrate;SiO2 layer is grown on the surface of ohmic contact layer, and double-groove strip-shaped ridge structure is formed on the surface, and the etching depth reaches the lower waveguide layer;Fill half-insulating InP:Fe in double groove, remove residual SiO2 layer;Insulating layer is grown on the surface of ohmic contact layer;Surface of insulating layer is prepared front metal electrode window;Insulating layer surface and inside front metal electrode window, front metal electrode layer is grown;Thicken front metal electrode layer;Substrate is thinned and polished, back metal electrode layer is grown, annealing treatment, packaging, and quantum cascade laser light frequency comb is obtained.The dispersion problem of mid-infrared quantum cascade laser is solved, the yield is high, the cost is low, the process is simple, and the manufacturing demand of large-scale application is met.

According to one embodiment, a surface-emitting quantum cascade laser includes a first electrode, a second electrode, and a stacked body provided between the first electrode and the second electrode. The stacked body includes a first cladding layer, a second cladding layer, a light-emitting layer provided between the second cladding layer and a portion of the first cladding layer, and a photonic crystal layer including a plurality of structure bodies provided between the light-emitting layer and the second cladding layer. The stacked body includes a mesa region. The mesa region includes the portion of the first cladding layer and the light emitting layer. A planar shape of the mesa region in a first plane crossing a first direction from the first cladding layer to the second cladding layer includes a recess.

A quantum cascade laser device includes a QCL element and a package. A light-emitting window through which laser light emitted from the QCL element passes is provided on a side wall of the package. The light-emitting window includes a small-diameter hole, a large-diameter hole larger than the small-diameter hole, a counterbore surface having an annular shape that connects the small-diameter hole and the large-diameter hole, and a window member disposed inside the large-diameter hole. An incident surface of a window member includes a first region in which an anti-reflection film is provided, and a second region metallized and formed in an annular shape to be separated from the first region and to surround the first region. The second region is joined to the counterbore surface through a solder member.

The proposed solution addresses the identified problem by providing a method that involves the use of artificial intelligence (AI) in combination with a portable laser spectroscopy device, such as a quantum cascade laser, allowing in situ analysis.

The invention relates to the technical field of lasers, in particular to a preparation method of a low-power-consumption mid-infrared quantum cascade laser, and the method comprises the steps: providing an epitaxial wafer which comprises an initial lower waveguide layer, an active layer and an initial upper waveguide layer which are stacked in sequence; patterning processing is carried out on the epitaxial wafer with partial thickness to form a substrate and an initial ridge-shaped structure located on the substrate, a groove is formed in the side face of the initial ridge-shaped structure, and the initial ridge-shaped structure comprises a lower waveguide layer, an initial active region and an upper waveguide layer which are sequentially stacked in the direction away from the substrate; the initial active region is transversely etched through the groove so as to remove the initial active region with a part of width, the remaining initial active region serves as an active region, the width of the upper waveguide layer and the width of the lower waveguide layer are both larger than the width of the active region, and the lower waveguide layer, the active region and the upper waveguide layer form a ridge-shaped structure. According to the invention, the preparation difficulty of the quantum cascade laser with the narrow ridge is at least reduced, and a narrower active region can be prepared.

In order to provide a THz-QCL element which takes advantage of the characteristics of a ZnO-based semiconductor material, a quantum cascade laser element has a semiconductor superlattice structure (a QCL structure), wherein the semiconductor superlattice structure has a plurality of unit structures that are stacked repeatedly. Each unit structures comprises three well layers having a composition of ZnO or ZnMgO, and barrier layers having a composition of ZnMgO or MgO that separates each well layer from each other and have a higher ratio of MgO than the left and right wells.

A mid-infrared laser based on on-chip integration of three devices and its fabrication method is disclosed, involving the intersection of semiconductor laser technology and optical communication technology. This invention alleviates the problem of the existing quantum cascaded laser (QCL) technology being unable to simultaneously achieve high modulation rate and high power. The mid-infrared laser includes a QCL unit, an EAM unit, and an SOA unit sequentially disposed on a substrate; the substrate comprises semi-insulating InP; the QCL unit, EAM unit, and SOA unit share the same ridge waveguide structure and are grown through epitaxial docking. The method described in this invention is applicable to mid-infrared band space communication scenarios with high requirements for laser modulation rate, output power, and single-mode stability.

The utility model discloses a light beam direction adjusting device for a quantum cascade laser, which comprises a cylindrical support and a lifting rotation adjusting seat sleeved outside the cylindrical support, and the lifting rotation adjusting seat can move up and down and rotate clockwise and anticlockwise outside the cylindrical support. And an internal thread cylinder is inserted into the center of the rear end of the lifting rotation adjusting seat. The novel adjusting anti-falling device is additionally arranged at the top end of the lifting rotation adjusting seat. When a user unscrews a locking screw rod to adjust the laser orientation of the quantum cascade laser, a pressing block A and a pressing block B of the device symmetrically clamp a cylindrical support to prevent an adjusting seat from falling down, a telescopic rod A and a telescopic rod B move in a hole, the support size difference and the position change of the adjusting seat are self-adapted by means of the elasticity of the pressing springs, and a plurality of pressing springs in a semi-compressed state provide stable clamping force, so that the laser orientation of the quantum cascade laser is adjusted. And the groove is attached to the arc-shaped outer wall of the support, friction force is increased, the anti-falling effect is further improved, and safety and stability of the device in the adjusting process are guaranteed.

The invention provides a quantum cascade laser external cavity dual-wavelength output device and method. The quantum cascade laser external cavity dual-wavelength output device comprises a double-end output quantum cascade laser, an aspheric collimating lens, a rotatable half-wave plate, a mid-infrared grating polarizer, a total reflection mirror and a blazed grating. A light beam is divided into two paths of polarized light with the same polarization state through polarization separation and polarization conversion, the polarized light is guided by an independent reflecting mirror and then enters the same blazed grating at different angles, the polarized light is diffracted by the blazed grating and then enters the reflecting mirror at the same diffraction angle, and then the polarized light returns to the laser through the reflecting mirror to form external cavity oscillation. The feedback intensity of the two paths can be balanced by rotating the half-wave plate, and the dual-wavelength independent tuning can be realized by adjusting the corresponding reflecting mirror. According to the invention, stable dual-wavelength output is realized by using a single grating, mode competition is effectively inhibited, the problem of wavelength lock loss caused by polarization mismatch is solved, and the dual-wavelength tunable filter has the advantages of simple structure, flexible tuning, stable output and high efficiency.

Embodiments include a computer readable storage medium, a user equipment, a method and an integrated circuit that perform operations. The operations include receiving a plurality of control resource sets (CORESETs), selecting a CORESET, wherein the CORESET includes one or more active transmission configuration indicator (TCI) states and determining a default beam or a pathloss reference signal (RS) based on a TCI state. Further operations include receiving a beam indication for a physical downlink control channel (PDCCH), wherein the PDCCH is received via one or more CORESETS, each having a plurality of TCIs, determining if the PDCCH collides with a second signal and determining whether to (a) drop the PDCCH or the second signal or (b) base a quasi co-location (QCL) of one of the PDCCH or the second signal on a QCL of the other one of the second signal or the PDCCH.

In certain examples, methods and apparatuses are directed to small molecules (e.g., drug-like molecules) binding to a target protein in live cells. In a specific example, a method includes: processing a laser beam, from a quantum cascade laser (QCL), carrying light in a wavelength range that overlaps a mid-IR range; using optics, in response to the laser beam, to process the light in a set of related beams along respective paths, including a reference path and a sample path, respectively towards a reference target and a sample target that includes living cells: and detecting, via a vibrational spectroscopy detector, small molecules binding to a target protein in live cells. The detection is carried out by collecting incident light, relative to the reference target and from the sample target, carried along respective incident paths and by discerning (e.g., measuring) vibrational probe frequency shifts in the sample target.

A low wavelength infrared Super Continuum (SC) signal from a master oscillator introduces two or more seeds into an amplifier that supports the Raman effect. A counter-propagating, high-power, continuous wave, or quasi-continuous wave quantum cascade lasers pump (amplifies) a first optical seed creating a cascading amplification of subsequent optical seeds forming two or more tunable wavelength coherent optical pump sources.

To provide a surface-emitting quantum cascade laser capable of improving characteristics.SOLUTION: According to an embodiment, a surface-emitting quantum cascade laser includes a first electrode, a second electrode, and a laminate provided between the first electrode and the second electrode. The stacked body includes a first clad layer, a second clad layer, a light emitting layer provided between a part of the first clad layer and the second clad layer, and a photonic crystal layer including a plurality of structures provided between the light emitting layer and the second clad layer. The stacked body includes a mesa region. The mesa region includes the part of the first cladding layer and the light emitting layer. A planar shape of the mesa region in a first plane intersecting a first direction from the first cladding layer to the second cladding layer includes a recess.SELECTED DRAWING: Figure 1

A QCL has a semiconductor substrate and an active layer provided on the semiconductor substrate. The active layer has a cascade structure that is formed by stacking a plurality of unit laminates including a light-emitting layer that generates light and an injection layer that transports electrons from the light-emitting layer. The light-emitting layer and the injection layer each have a quantum well structure in which a quantum well layer and a barrier layer are alternately stacked. A separation layer is provided between the light-emitting layer and the injection layer in the unit laminate, and the separation layer includes a separation quantum well layer having a layer thickness that is smaller than an average layer thickness of the quantum well layer included in the light-emitting layer and smaller than an average layer thickness of the quantum well layer included in the injection layer.

The present disclosure provides a topological surface emitting quantum cascade laser and a preparation method thereof. The preparation method of the topological surface emitting quantum cascade laser comprises: sequentially forming a metal bonding layer, an active layer and an upper contact layer on a substrate; performing photoetching development on the upper contact layer by using a mask, coating photoresist at the patterned position of the mask, and then performing electron beam evaporation of the metal with the photoresist on the upper contact layer to form a metal layer; stripping the metal layer with the photoresist to obtain a metal topological pattern layer; and etching the upper contact layer to form an absorption boundary at the edge of the metal topological pattern layer, so as to enhance the absorption loss of the whispering gallery mode, and keep the topological surface emitting quantum cascade laser in a working state of the topological mode.

A beating spectroscopy device includes: first and second quantum cascade lasers; a quantum cascade detector; and a sample holder configured to hold a sample on an optical path between the second quantum cascade laser and the quantum cascade detector. Lights from the first and second quantum cascade lasers are detected by the quantum cascade detector while a wavelength of the light from the second quantum cascade laser is changed to scan a frequency of a beating signal having a frequency in accordance with a wavelength difference between the lights from the first and second quantum cascade lasers.

A quantum cascade laser device according to the present disclosure comprises: a semiconductor substrate; a cascade laser region and a difference frequency waveguide laminated on the semiconductor substrate; and a grating coupling region. The grating coupling region is configured to couple, to a waveguide mode of the difference frequency waveguide, light emitted from the cascade laser region in a direction inclined with respect to an upper surface of the semiconductor substrate.

The invention belongs to the technical field of semiconductor lasers, and particularly relates to a gallium nitride quantum cascade laser based on a silicon-based waveguide structure and a preparation method of the gallium nitride quantum cascade laser. The technical prejudice that a silicon substrate is not suitable for a GaN-based THz-QCL is broken through, high-resistance silicon is innovatively adopted as the substrate, the doping concentration and thickness of the highly-doped GaN plasma layer, the multi-period quantum cascade active region layer and the low-doped GaN contact layer are regulated and controlled through a system, and a novel single-metal waveguide structure is constructed. Experiment and simulation results show that the structure realizes the comprehensive performance that the light field limiting factor is 0.1-0.8 and the waveguide loss is 10-150cm <-1 > in the frequency band of 7-10THz; especially in a 8.5-10THz high frequency band, the light field limiting factor obviously exceeds a device based on a SiC substrate in a citation patent, and the loss is always controlled to be below 150cm <-1 > and is in a reasonable range capable of realizing net gain.

The invention discloses an epitaxial structure of a high-power quantum cascade laser suitable for a high-temperature working environment. The epitaxial structure comprises an InP substrate, an InP buffer layer, an InP lower limiting layer, an InGaAs lower waveguide layer, an InGaAs / InAlAs superlattice active region, an InGaAs upper waveguide layer, an InP upper limiting layer and an InP ohmic contact layer from bottom to top in sequence. The InGaAs / InAlAs superlattice active region comprises a lasing region and a relaxation region, the lasing region is a core region for electrons to generate laser through transition, the relaxation region is a channel for rapidly discharging the electrons through phonon scattering and injecting the electrons into the next lasing region, and the lasing region and the relaxation region are alternately cascaded to jointly realize an efficient process that one electron emits light for multiple times. Through a gradually-changed energy band structure, current carriers are prevented from escaping from a micro-strip above an upper lasing energy level, wave function overlapping between the high energy level and an upper excited state of an active region is reduced, current carrier leakage is inhibited, through effective strain compensation, net strain of an epitaxial material is reduced, and the requirements of a metal organic chemical vapor deposition epitaxial process are met.

To provide a surface emitting quantum cascade laser that oscillates in a single mode, and a control method thereof.SOLUTION: A surface emitting quantum cascade laser includes: a first surface that emits laser light; a second surface opposite to the first surface; an active layer; a photonic crystal; and first to third electrodes. The active layer is provided between the first surface and the second surface. The photonic crystal is provided between the active layer and the first or second surface, and is located between the first surface and the second electrode. The first electrode is provided on the first surface and is located outside a region where the laser light is emitted. The second electrode is provided on the second surface. The third electrode is provided on the second surface and separated from the second electrode. The active layer extends between the first surface and the second electrode and between the first surface and the third electrode.SELECTED DRAWING: Figure 1

According to one embodiment, a surface-emitting quantum cascade laser includes a substrate; a mesa portion of a semiconductor stacked body located on the substrate, and a reflective film located at a sidewall of the mesa portion. The mesa portion includes a light-emitting layer emitting light due to an intersubband transition of a carrier, and a photonic crystal layer including a two-dimensional diffraction grating.