56 results about "Semiconductor quantum wells" patented technology

A multi-wavelength VECSEL includes an active region comprising a plurality of semiconductor quantum wells having an intrinsically broadened gain with a wavelength selective filter disposed within the cavity to provide a laser output that oscillates at two or more separated wavelengths simultaneously. A non-linear crystal may be provided in the cavity to emit radiation at a frequency in the THz range that is the difference of the frequencies associated with two of the separated wavelengths.

A microstrip stabilized quantum well resonance-tunneling generator which generates electromagnetic waves for millimeter and submillimeter wavelength range is provided The generator includes a resonant tunneling semiconductor quantum well diode, and a microstrip resonator. The resonant tunneling diode, the microstrip resonator and interconnecting lines and junctions are fabricated as a monolithic integrated device on a common substrate. As a result, the monolithic integrated device provides the expansion of the operation frequency range toward the terahertz region as a result of reduction of the parasitic inductance as well as of minimizing the other parasitic parameters of the electric circuitry connecting the resonant tunneling diode and resonator.

The invention discloses a terahertz wave band wireless transmitting and receiving device and a transmitting and receiving method thereof. The transmitting and receiving device comprises a transmitting terminal composed of a first cold head, a terahertz quantum-cascade laser and a first polyethylene window plate, an optical path part containing two off-axis parabolic mirrors and air and a receiving terminal composed of a second cold head, a terahertz quantum well detector and a second polyethylene window plate. The invention has the advantage that currently undistributed frequency range of electromagnetic wave is selected to transmit and receive electromagnetic wave, the absorption of the selected frequency point of electromagnetic wave by the air is relatively weaker, thus reducing the attenuation loss of terahertz wave during the transmission process; the semiconductor quantum-cascade laser which has high energy conversion efficiency and small volume, is easy to integrate, and can work for long time and perform mass production is adopted by the transmitting terminal; the semiconductor quantum well detector which has small volume, is stable and reliable and can perform mass production is adopted by the receiving terminal; and the adopted semiconductor laser and detector both can operate at high frequency, thus being suitable for future terahertz communication applications.

The invention discloses a surface plasmon excimer electrically-induced excitation source with a medium-metal near field coupling structure. The surface plasmon excimer electrically-induced excitation source comprises a substrate, semiconductor quantum well epitaxial layer, a metal layer and a coupling output structure. The semiconductor quantum well epitaxial layer is loaded on the surface of the substrate. The metal layer is loaded on the surface of the semiconductor quantum well epitaxial layer. The coupling output structure is located in the metal layer. The invention further discloses a manufacturing method of the surface plasmon excimer electrically-induced excitation source. The method includes the steps that the semiconductor quantum well epitaxial layer is grown on the substrate; a device unit is etched on the grown semiconductor quantum well epitaxial layer; the metal layer is deposited on the etched device unit; the coupling output structure is manufactured in the deposited metal layer. According to the surface plasmon excimer electrically-induced excitation source, the semiconductor quantum well material is adopted to serve as an active medium, based on the near field coupling principle, the quantum efficiency is high, the light emitting wavelength range is wide, the excitation efficiency is high, the manufacturing process is simple, integration is conducted conveniently, and the surface plasmon excimer electrically-induced excitation source and the manufacturing method have great research value and application prospects.

A surface-emitting photonic device including a structure disposed therein to enhance a performance thereof. The structure includes a two dimensionally periodic second order distributed feedback device (DFB) to emit diffraction limited outcoupled laser light having a predetermined wavelength along a propagation direction that is substantially normal to a plane of the DFB, and a first order distributed Bragg reflector (DBR) coplanar with, adjacent to and surrounding the DFB, a geometry of the DBR being selected such that a bandgap of the DBR is maximized and centered around the predetermined wavelength of the emitted light, a substrate, and either an optical gain layer, or a semi-conductor quantum well laser disposed within the substrate.

A device employing a quantum well structure having a pattern that is defined by a photolithographically patterned top gate electrode. By defining the active area of the quantum well structure by the patterning of the top gate electrode there is no need to pattern the quantum well structure itself, such as by etching or other processes. This advantageously allows the active are of the quantum well structure to be patterned to a very small size, without the damaging edge effects associated with the patterning of the quantum well structure itself.

This invention discloses an electric pump micro-cavity laser outputting laser from a port of an integrated straight waveguide based on a whisper cloister mode theory and composed of a die and heat sink, in which, the die is a chip processed in complecated processes of photoetch, corrosion, oxidation and evaporation of electronic beams on the epitaxial chip of a semiconductor quantum well laser, and the center of which is a micro-disk or a micro-loop, a straight waveguide of several mum wide, several decades-several hundreds long and same thick to the disk or the loop is integrated along the tangent of the edge of the disk or loop, in which, an ohmic contact metal film is prepared on the surface of the disk or the loop and a sloder is applied to weld the die and the heat sink.

A surface plasmon electro-excitation and electrical modulation integrated device comprises a back electrode, a semiconductor substrate, a semiconductor active structure, a first dielectric layer, a metal electrode and waveguide structure, a directional coupling structure, a second dielectric layer, a graphene structure, and a graphene metal electrode and waveguide structure. By electrically injecting a semiconductor quantum well material, the surface plasmons on metal and semiconductor medium interfaces are excited by means of near-field coupling and are propagated on a metal-medium waveguide after directional coupled output, and thus, surface plasmon electro-excitation is realized. Based on the fact that the Fermi level and dielectric constant change when the concentration of graphene carriers changes with change of gate voltage applied, the transmission bandwidth and high speed of electro-excited surface plasmons are modulated through the voltage applied to graphene in a field effect transistor-resembling structure composed of metal electrodes, a second dielectric layer and graphene.

The invention relates to a method for regulating the ratio of Rashba and Dresselhaus spin-orbit coupling for a semiconductor quantum well material. According to the method, an undoped high-quality semiconductor quantum well material is selected, light whose energy is higher than that of the band gap of the semiconductor quantum well is used for irradiating a sample, and meanwhile, the temperature of the semiconductor quantum well is changed, so that the ratio of the Rashba and Dresselhaus spin-orbit coupling in the quantum well is regulated. By means of the method, the ratio of Rashba and Dresselhaus spin-orbit coupling is regulated through the effect that the number of photoproduced excitons in the semiconductor quantum well is changed along with the temperature as well as the control effect of ionized excitons on a built-in electric field, the method is simple and easy, and the regulating effect is significant.

A polarization modulation photoreflectance technique has been developed for optical characterization of semiconductor quantum confined structures. By using a tunable laser source in conjunction with polarization state modulation, a single beam modulation spectroscopy technique may be used to characterize the optical response of semiconductor materials and structures. Disclosed methods and instruments are suitable for characterization of optical signatures of quantum electronic confinement, including resolution of excitonic states at the band edge or other direct or indirect critical points in the band structure. This allows for characterization of semiconductor quantum well structures, for characterization of strain in semiconductor films, and for characterization of electric fields at semiconductor interfaces.

The invention belongs to the technical field of light wave detectors, and particularly relates to a light detector of a semiconductor quantum well. The detector comprises a semiconductor layer, a quantum layer and a layer of a subwavelength periodic structured metal film. The quantum well at least comprises two energy levels and has a certain carrier concentration. Incident light wave with a certain spectrum width enters the semiconductor layer vertically or obliquely; the incident light wave stimulates the periodic structured metal film/a surface plasma of a quantum well interface; the surface plasma is absorbed by the semiconductor quantum well and an electronic subband transition process is generated; and the transited electrons form current signals under the externally applied bias voltage. According to the light detector of the semiconductor quantum well disclosed by the invention, the detection efficiency can be greatly improved.

The invention belongs to the technical field of the photodetection, particularly to a semiconductor quantum well photon detector, which includes a semiconductor layer, and a quantum well layer is arranged near the surface of one side of the semiconductor, wherein the quantum well is provided with certain carrier density and at least two energy levels; a metal layer with the sub-wavelength hole periodic structure, arranged on the surface of one side of the semiconductor; an incident light wave, on the direction vertical to the one side surface of the semiconductor and the quantum well layer, incident from the front of the metal layer or the other surface of the semiconductor layer, and finally adsorbed by the quantum well layer. The invention performs the optical couple by using the metal sub-wavelength periodic structure, realizes the active absorption of the quantum well structure to the vertical incident light, meanwhile the semiconductor energy gap technology is combined with the surface of the metal periodic structure, which realizes the convenient tune of the coupling way and the semiconductor quantum well light wave detection in the wide wavelength range.

The invention discloses a microwave oven housing material comprising single layer or multi layer wire mesh screen and single layer or multi layer metallic dielectric composite films of quasi-semiconductor well symmetrical structure. The invention can transparent property in the visible region on one hand, and mask requested microwave in working section or with longer wavelength.

The invention discloses a method for measuring carrier concentration in a semiconductor quantum well. The method includes steps of measuring local conductance distribution of the cross section of the semiconductor quantum well by the electric detection mode of a scanning probe microscope; setting up a numerical model capable of reflecting relation between a conducting probe-quantum well Schottky contact conductivity and carrier concentration in the quantum well; and determining parameters and carrier concentration of the quantum well of the numerical model according to the measured conductivity distribution. The method is high in spatial discrimination and has advantages in analysis of a narrow quantum well and in coupling of the quantum well, is applicable to wider carrier concentration range from non-degeneracy to degeneracy doping conditions, and has significance value for analysis of internal performances of a semiconductor photoelectric device taking a quantum well as a functional structure.

The invention relates to a preparation method for a bismuth-based non-rectangular group III-V semiconductor quantum well. The preparation method comprises the step of growing a potential well material and a potential barrier material of a group III-V semiconductor quantum well, wherein bismuth is added in the growth processes of both the potential well material and the potential barrier material. According to the preparation method, bismuth beam source shutters are opened simultaneously in the processes of growing the potential well material and the potential barrier material of the quantum well, and a non-rectangular quantum well structure is realized by utilizing the group III element interdiffusion caused by the bismuth. By the method, material components can be controlled effectively; the problem that the conventional growth method is only suitable for growing a rectangular quantum well structure with component mutations is solved; greater freedom is introduced to the design and the implementation of the structure and the functional of quantum; the preparation method disclosed by the invention is suitable for adopting a plurality of material growth means, such as molecular beam epitaxy and atomic layer deposition; and the operation process is simple and convenient.

The present invention discloses a wideband low-loss semiconductor saturable absorption lens for mode-locking laser. Said absorption lens is successively formed from reflector supporting piece, adhesive layer, metal (gold or siler) film reflecting layer, transparent semiconductor layer (aluminum gallium arsenide and indium aluminium gallium arsenide), semiconductor quantum well saturable absorbent(gallium arsenide, indium gallium arsenide) and transparent semiconductor layer (aluminum gallium arsenide and indium aluminum gallium arsenide). Between the metal film reflecting layer and adjacent transparent semiconductor layer a transparent medium layer with low refractive index (less than 1.65) can be inserted or between said transparent medium layer and transparent semiconductor layer a high reflecting film layer formed from high-low refractive index medium layer pair can be more inserted.

Methods and devices for creating an anisotropic strain in a semiconductor quantum well structure to induce anisotropy thereof are disclosed herein. Initially, a substrate is provided, and a quantum well structure formed upon the substrate. A first crystalline layer (e.g., a GaAs layer) having a first crystalline phase can then be deposited upon the quantum well structure. Thereafter, a second crystalline layer (e.g., a GaN layer) having a second crystalline phase and a thickness thereof can be formed upon the first crystalline layer to thereby induce an anisotropic strain in the quantum well structure to produce a quantum well device thereof. Additionally, the second crystalline layer (e.g., GaN) can be formed from a transparent material and utilized as an anti-reflection layer. By properly choosing the thickness of the second crystalline layer (e.g., a GaN layer), a desired anisotropic strain as well as a desired anti-reflection wavelength can be achieved.

Disclosed is an optical reading method with which can be realized a system that compensates for handling of an information pattern not recognizable to the naked eye, wherein a nonvisible information pattern such as a bar code or a QR code is printed on an information recording medium or an object to be managed, and that provides high security or guaranteed product quality. When an information recording medium (11) having an information pattern (12) is placed in or transported to a prescribed position, the information pattern (12) is irradiated with excitation light (H1), which is emitted from a light-emitting diode (13) and has higher energy than the band gap of a semiconductor quantum dot, and the semiconductor quantum dot is thermally expanded. Then, light is emitted from the thermally-expanded quantum dot with a wavelength which transitions to the long-wavelength side compared to the wavelength emitted from the quantum dot prior to thermal expansion, this light beam is received by an optical sensor (14), which has a sensitivity to the longer wavelength portion of light which is emitted and transitions to the long-wavelength side, and the information pattern (12) is read by an information judgment unit (15).

Present invention provides THz radiative generation method based on semiconductor quantum well negative effective mass system, and P quantum well negative effective mass p + pp + diode device structure. Under appropriate doping and bias condition, diode generates THz electric current self-oscillation due to high-field domain forming, designing tunable semiconductor quantum well negative effective mass THz oscillation source, said oscillation source having compactness, light in weight, easy integrating etc advantages.

The invention discloses a method for independently regulating and controlling spin orbit coupling parameters of a semiconductor quantum well and belongs to the technical field of semiconductor spintronics. The method comprises steps of selecting an asymmetrically doped semiconductor quantum well sample with a controllable metal gate; loading the sample into a piston sleeve type electric measurement high-voltage cavity, and applying pressure and a gate voltage to the sample; acquiring rashba and Dresselhaus spin orbit coupling parameters through anti-weak localization measurement, and realizingindependent regulation and control of the two spin orbit coupling parameters by adjusting the pressure and the grid voltage at the same time. The method for regulating and controlling the spin orbitcoupling strength parameters of the semiconductor quantum well is high in feasibility and can be carried out in situ, a new sample does not need to be prepared, independent regulation and control of the two parameters can be achieved respectively, and the regulation and control effect is remarkable.