117results about How to "Improve Modulation Capabilities" patented technology

The invention relates to the technical field of terahertz spectrums, in particular to a graphene-based all-optically controlled ultra-high speed terahertz intensity modulator. The technical problems of low modulation speed and narrow spectrum range of the conventional terahertz intensity modulator are solved, and the application range of a system is widened. According to the graphene-based all-optically controlled ultra-high speed terahertz intensity modulator, gold nanoparticles are adopted, so that the photon absorption efficiency of graphene is enhanced, the concentration of photon-generated carriers is improved, the absorption of terahertz waves is further enhanced, and the modulation effect of the modulator is enhanced. The graphene-based all-optically controlled ultra-high speed terahertz intensity modulator comprises a terahertz wave generation device, a pumping light wave generation device, a terahertz intensity modulator and a terahertz wave detection device, which are connected to finish the design of the graphene-based all-optically controlled ultra-high speed terahertz intensity modulator. The graphene-based all-optically controlled ultra-high speed terahertz intensity modulator is mainly applied to the fields of terahertz communication systems and terahertz researches.

Low cost implementation of broadband upstream transmission for local and access network applications is made possible through the use of modulated downstream signals in a wavelength division multiplexed (WDM) passive optical network (PON) to injection-lock vertical-cavity surface-emitting lasers (VCSELs) for operation as stable, uncooled, and directly-modulated upstream transmitters. By way of example and not limitation, an optical network unit comprises: downstream input, photoreceiver, tunable laser, upstream output, and means for directionally coupling the downstream input into the tunable laser for modulating the output wavelength which is coupled to the upstream output.

The invention discloses a Si-based gallium oxide film back gate solar-blind ultraviolet ray transistor and a preparation method thereof, and belongs to the photoelectric detector and semiconductor transistor technical field; the transistor comprises the following parts arranged from bottom to top in sequence: a back gate electrode layer, a substrate layer, a light-sensitive layer and an interdigital electrode layer; the substrate employs a p-Si / SiO2, and a gallium oxide film is prepared and grown on a SiO2 layer of the p-Si / SiO2 substrate so as to serve as the light-sensitive layer; an Au / Ti electrode is sputtered on the gallium oxide film so as to form the interdigital electrode; a metal Au film is sputtered on the Si layer of the backside of the p-Si / SiO2 substrate so as to serve as theback gate electrode. The preparation process is simple, and a silicon base device can be easily integrated; the method is strong in controllability, easy to operate, and the obtained film is compact in surface, even and stable in thickness, good in repeatability, easy to integrate, and can be massively made; the prepared device structure can be regulated and controlled by the gate voltage so as toobtain high solar-blind ultraviolet ray current gains.

The invention relates to the technical field of microwave power device in semiconductor materials, discloses a AlGaN / GaN HEMT multilayer field board device of recessed grid, and meanwhile discloses a method for manufacturing AlGaN / GaN HEMT multilayer field board device of the recessed grid; on the basis of common AlGaN / GaN HEMT device manufacturing process, the method comprises the steps of photo-etching grid images after forming Ohm contact of a source electrode and a drain electrode, etching AlGaN extension layer of a part of the grid image, after evaporating grid metal, firstly manufacturing a grid connection field board and then a source connection field board to form the AlGaN / GaN HEMT multilayer field board device of the recessed grid. Utilization of the invention can efficiently improve puncturing characteristic, transconductance and threshold value voltage of the AlGaN / GaN HEMT device, and at the same time of improving the device plus, availably suppress phenomenon of current collapse of the AlGaN / GaN HEMT device.

The present invention relates to a decoding apparatus and method, a program storage medium, and a program, which allow high-performance decoding of a modulation code encoded in accordance with a variable-length table. A 17PP-SISO decoder 181 performs SISO decoding on a signal supplied from a PR-SISO decoder 81 by using a Viterbi decoding algorithm or a BCJR decoding algorithm in accordance with a trellis represented by paths corresponding, in a one-to-one fashion, to overall transitions in an entire encoding process in accordance with an encoding table 201 of a 17PP code. A resultant SISO-decoded signal is supplied to a turbo decoder 84 via a deinterleaver 83. The turbo decoder 84 performs turbo decoding on the signal output from the 17PP-SISO decoder 181. The present invention can be applied to a recording / reproducing apparatus for recording / reproducing a signal on / from a storage medium such as a high-density optical disk.

The invention discloses a graphene based surface plasmon polariton electric-absorption light modulator.The graphene based surface plasmon polariton electric-absorption light modulator comprises a substrate, a first micro-nano waveguide, a second micro-nano waveguide, a dielectric layer, first single-layer graphene, a first electrode and a second electrode, wherein the first micro-nano waveguide and the second micro-nano waveguide are stacked on the substrate, the dielectric layer and the first single-layer graphene are located between the first micro-nano waveguide and the second micro-nano waveguide, and the first electrode and the second electrode are respectively connected with the first micro-nano waveguide and the second micro-nano waveguide and are used for exerting modulation voltage.At least one of the first micro-nano waveguide and the second micro-nano waveguide is a metal waveguide.The first single-layer graphene is located between one metal waveguide and the dielectric layer.One of the electrodes is connected with the corresponding metal waveguide through the first single-layer graphene.The graphene based surface plasmon polariton electric-absorption light modulator adopts the structural design of vertical arrangement, integrates with the advantages of the graphene and SPP and enables the modulation height to be higher than the height of an existing electric-absorption light modulator and to reach 70% or above.In addition, the light modulator is smaller in structural capacitance, and the overall response speed of the light modulator is greatly improved.

A surface emitting laser is provided with a first multilayer Bragg reflecting mirror including a first layer, a second multilayer Bragg reflecting mirror including a second layer, and an optical resonator unit that is held between these multilayer Bragg reflecting mirrors and includes an active layer. Further, the optical resonator unit contacts with the first layer and second layer respectively. The effective refraction index neff of the resonator unit is larger than either the first layer or the second layer, and an optical length neffL of the optical resonator unit has a relationship with an oscillating wavelength λ of the surface emitting laser to satisfy the following relationship: 0.5λ<neffL≦0.7λ.

The invention relates to a magneto-optic plasma biosensor, which belongs to the field of optical sensing, and particularly relates to the magneto-optic surface plasma resonance technology. The magneto-optic plasma biosensor comprises a silicon dioxide substrate and a gold film, wherein on the silicon dioxide substrate, and between the substrate and the gold film, a titanium nitride layer, a silicon dioxide layer, a yttrium iron garnet layer and a cerium-doped yttrium iron garnet layer are sequentially arranged in a direction from the substrate to the gold film. The magneto-optic plasma biosensor provided by the invention has the beneficial effects of novel structure, high quality factor, material stability, difficulty in oxidization, simple in structure, and low in cost.

The invention discloses a method for manufacturing a three-dimensional superconduction micro-nano device, relating to three-dimensional micro-nano device technology. The method provided by the invention comprises the following steps: (1), growing a superconduction electrode contact block or a connecting wire; (2) placing and fixing a processed sample in the step (1); (3), putting the sample fixed on a sample support on a sample stage arranged in a vacuum chamber of an ion beam device; (4) growing a superconduction micro-nano material freely standing on the superconduction electrode contact block or the connecting wire; (4), controlling deformation of the micro-nano material manufactured in (4B); and (6), obtaining a finish product. In the manufacturing method provided by the invention, a superconduction micro-nano structure which is not positioned in a support substrate plane is manufactured based on the control for the deformation of the freely-standing nano material by ion beam irradiation, so as to form the three-dimensional superconduction micro-nano device which is in a certain included angle with the support substrate plane; and the method provided by the invention is flexible in process, high in efficiency and good in control.

The invention provides a full two-dimensional gas chromatograph modulator based on a semiconductor heating and cooling technique. The full two-dimensional gas chromatograph modulator comprises a refrigeration system, a heating system and a control system. The refrigeration system and the heating system are respectively connected to the control system. The refrigeration system comprises a heat radiating device, a refrigeration sheet, a first heat insulating pad and a cold conduction block. The heat radiating device, the first heat insulating pad and the cold conduction block are orderly laminated tightly. The refrigeration sheet is installed in the first heat insulating pad. The heating system comprises a heater, a second heat insulating pad and a heat conduction block. The second heat insulating pad and the heat conduction block are closely laminated. The heater is installed in the second heat insulating pad. The modulator has a simple structure, is easy to control and install and can effectively save the experimental cost and the laboratory space.

The invention discloses an all optical fiber type electro-optic modulator based on a D-shaped double core optical fiber, and belongs to the field of a special optical fiber, optical fiber communication and signal processing. A core (2) in the D-shaped double core optical fiber (1), which is positioned in the center, is connected with an input end single mode optical fiber, and a core (3) close to a boundary is connected with an output end single mode optical fiber. The surface of the D-shaped double core optical fiber (1) is coated with an electro-optical polymer (4), and both sides of the electro-optical polymer are plated with metal electrodes (5) and are connected with voltage loading devices (6). When voltages (6) are loaded, a refractive index of the electro-optical polymer (4) is changed along with the voltages, the core (3) close to the electro-optical polymer (4) is sensitive to change of the refractive index of the electro-optical polymer (4), and the core (2) positioned in the center is insensitive to the change of the refractive index of the electro-optical polymer (4). When the voltages (6) loaded to both the ends of the electro-optical polymer (4) are changed, a coupling degree of two cores is changed, so that strength modulation of light can be achieved.

The invention relates to a redundant configuration inertial measurement unit biaxial rotation modulation method. A universal redundant inertial measurement unit constant error model is constructed byutilizing the characteristic that a redundant configuration inertial measurement unit constant error is formed by linearly combining sensor constant errors of the redundant configuration inertial measurement unit constant error, and constant error modulation is performed on the redundant inertial measurement unit through double-axis rotation to realize error compensation. On the basis, the influence of carrier angular motion on biaxial rotation modulation in actual navigation is considered, a biaxial rotation scheme based on an attitude angle is provided to realize error modulation under a navigation system, the carrier angular motion is effectively isolated, and the error modulation effect is improved. According to the invention, constant error modulation can be carried out on the redundant configuration inertial measurement unit, a good modulation effect can still be achieved under the condition that the carrier performs angular motion, and the navigation precision of the redundant configuration inertial measurement unit is significantly improved. The invention belongs to the technical field of inertial navigation, and the method can be applied to error compensation of the redundant configuration inertial measurement unit.

The invention discloses a photonic crystal micro-ring modulator chip based on a lithium niobate film. The photonic crystal micro-ring modulator chip comprises a chip substrate, a chip lower cladding layer, a waveguide core layer and a chip upper cladding layer. According to the invention, an input optical waveguide, a photonic crystal micro-ring modulation structure and an output optical waveguideare integrated on a waveguide core layer, wherein the photonic crystal micro-ring modulation structure is composed of a single straight-through waveguide and a closed annular waveguide, the straight-through waveguide is of a two-dimensional line defect photonic crystal waveguide structure, the annular waveguide is of a two-dimensional circular lattice annular resonant cavity type photonic crystalwaveguide structure, a modulation electrode is arranged on the annular waveguide, the waveguide core layer is made of a lithium niobate film material, the device size can be greatly reduced and the integration degree can be improved while the high electro-optical coefficient is achieved, the electro-optical effect is enhanced in combination with the photonic crystal waveguide slow light effect, the modulator works at a low driving voltage, and the structural size is further reduced. The modulator chip is simple in manufacturing process and easy to integrate and expand, and has good reliability and performance stability.

The invention provides a grid enhanced-power semiconductor field effect transistor which comprises a drain region (201), a drift region (202), a dielectric layer (203), a split grid (204), a grid electrode (205), an n+ layer (206), a source electrode (207) and a channel region (208), wherein K values of the dielectric layer (203) are distributed according to a certain law, namely, the K values become smaller from the source electrode to the drain electrode. In the grid enhanced-power semiconductor field effect transistor, the dielectric layer, the K values of which are distributed according to a certain law, is used for replacing an original side oxide structure, therefore, the drain-source on resistance is reduced on the condition that the withstand voltage of a device is not sacrificed. The transistor is compatible with the conventional MOSFET (metal-oxide-semiconductor field effect transistor) process, has very strong feasibility and can meet the application requirements of a power electronic system more easily.

The invention relates to a terahertz wave electric control modulation method based on a Dirac semimetal microstructure. The method is realized through a terahertz wave modulator based on a Dirac semimetal microstructure. The terahertz wave modulator comprises a polymer flexible substrate, an epitaxial layer, an insulating layer and a Dirac semimetal microstructure, wherein a gold thin layer and achromium thin layer are arranged on the Dirac semimetal microstructure; the chromium thin layer is arranged on the gold thin layer; the epitaxial layer is arranged on the polymer flexible substrate; the insulating layer is arranged on the epitaxial layer; the Dirac semimetal microstructure is an active region of the terahertz wave modulator and is arranged on the insulating layer; and external voltage is applied between the Dirac semimetal microstructure and the epitaxial layer to change the corresponding Fermi level so as to adjust the waveform of the resonance spectral line. Compared with the prior art, the method has the advantages that the amplitude modulation depth and the frequency modulation depth are improved, the manufacturing process is simpler, the feasibility is better, and thelike.

The invention discloses a double-gate graphene transistor with a silicon substrate and an aluminium oxide gate dielectric, and a preparation method, which are mainly used for solving the problems of low channel carrier mobility and carrier scattering of a graphene transistor prepared by the prior art. The preparation method comprises the following realization steps of: depositing a layer of Al2O3 on an epitaxial 3C-SiC surface on a Si substrate, and photoetching a double-gate graph; placing the etched sample in a quartz tube, generating a carbon film by reacting Cl2 with SiC, then placing the carbon film sample in Ar gas and annealing to generate graphene; etching off Al2O3 at the both sides of the graphene sample and 60-400 nm away from a conductive channel to form a double-gate groove; finally depositing a metal layer on the graphene sample and etching to form transistor metal contact. The double-gate graphene transistor provided by the preparation method disclosed by the invention has the advantages of being high in carrier mobility, good in scattering effect suppression performance, and capable of regulating a channel carrier concentration, as well as can be used for producing a large-scale integrated circuit.