183results about How to "High nonlinear coefficient" patented technology

The invention relates to a zinc oxide voltage dependent resistor medium material and a resistor preparation method, which belongs to the technology field of electronic material. The components of the zinc oxide voltage dependent resistor medium material comprises 85 percent to 95 percent of ZnO, 2 percent to 6 percent of Bi2O3, 1 percent to 5 percent of TiO2, 1 percent to 3.5 percent of Sb2O3, 1 percent to 4 percent of MnCO3, 1.2 percent to 5 percent of Co2O3, 0.2 percent to 1 percent of Cr2O3, 0.1 percent to 1 percent of ZrO2, 0.2 percent to 1 percent of Ni2O3 and 1.2 percent to 3 percent of SiO2. The chip type zinc oxide resistor preparation method comprises the steps of dosing according to a zinc oxide resistor medium material medium material, material mixing, material grinding, casting sizing agent making, casting, inner electrode printing, laminating, baking, temperature isostatic pressing, cutting, gule discharging, sintering, end electrode making, and the like. The zinc oxide voltage dependent resistor medium material of the invention is suitable for making chip type voltage dependent resistor; the prepared chip type voltage dependent resistor has the characteristics of low voltage-dependent voltage, high nonlinear coefficient and stable voltage-dependent characteristic, the sintering temperature is moderate, preparation technology is simple and is easy to control, and cost is low.

The invention discloses a formulation of an AC zinc oxide resistance chip. The formulation is characterized by comprising the following additives and a main material ZnO by weight percentage: 4.0 to 4.9 percent of Bi2O3, 3.0 to 4.0 percent of Sb2O3, 0.5 to 1.0 percent of SiO2, 2.0 to 3.0 percent of Co2O3, 0.50 to 0.80 percent of Cr2O3, 0.50 to 0.80 percent of MnCO3, 0.70 to 0.90 percent of NiO, 0.03 to 0.05 percent of aluminum nitrate, 0.10 to 0.20 percent of glass dust, 0.07 to 0.10 percent of B2O3 and 85.0 to 88.0 percent of ZnO. The formulation of the resistance chip has the following characteristics and advantages: the nickel protoxide and the glass dust are introduced into the formulation, so that the stability and the aging performance of the internal structure of the resistance chip is more excellent; and 2, dosage of cobalt sesquioxide, dibismuth trioxide and diantimony trioxide are added in the formulation, the mixture ratio of each composition is more reasonable, and the non-linearity coefficient of the resistance chip can be improved, the pressure ratio is reduced, the circulation capability is improved, and the comprehensive performance is excellent.

The invention discloses a zinc oxide piezoresistor material which comprises a main material and an additive, wherein the main material comprises 92-97mol% of ZnO; and the additive comprises 0.5-1.5mol% of Bi2O3, 0.1-1.2mol% of Cr2O3, 0.1-1.5mol% of MnCO3, 0.1-1.0mol% of BaCO3, 0.1-1.5mol% of Co3O4, 0.1-1.2mol% of SnO2, 0.1-1.0mol% of SrCO3, 0.1-1.0mol% of V2O5, 0.1-1mol% of H3BO3, and 0.005-0.1mol% of Al2(NO3)3.9H2O. When the zinc oxide piezoresistor material is adopted for preparing a finished product, the sintering temperature can be reduced to 900-940 DEG C while various excellent properties are ensured; when the zinc oxide piezoresistor material is adopted for preparing a sheet zinc oxide piezoresistor, a silver palladium alloy with a silver mass fraction greater than or equal to 85% can be matched as an inner electrode or pure silver can serve as the inner electrode; and the cost is lowered greatly.

The invention discloses a self-collimating high-stability entanglement source module and a system thereof, comprising a dual-color polarization beam splitter DPBS, a two-color half-wave plate DHWP, afirst plane mirror M1, a second concave mirror CM2, a first concave mirror CM1 and a second plane mirror M2 which are sequentially arranged and form an optical loop, wherein a periodically polarized crystal is disposed on the optical path between the first concave mirror CM1 and the second concave mirror CM2. An advantage of the invention is that both the focusing of the pump beam and the collimation of the generated spontaneous parametric down-converting photons can be achieved by using the first concave mirror and the second concave mirror. The focusing lens of the pumping light and the fiber collimator required for photon collection may be omitted, which greatly simplifies the complexity of the optical path, and highly integrates and miniaturizes the entangled source module.

The invention provides an all-optical wavelength converter based on a photonic crystal optical fiber four-wave frequency mixing effect. The all-optical wavelength converter comprises a laser, an optical crystal optical fiber and an optical filter, wherein the laser is a long pulse laser or a continuous laser with a pulse width more than tens of picoseconds, and the laser is used for outputting a pump light and providing a converting wavelength; the photonic crystal optical fiber is used for receiving and transmitting an output light of the laser; a laser beam can generate a degenerated four-wave frequency mixing effect during being transmitted in the photonic crystal optical fiber; and the laser beam output from the photonic crystal optical fiber passes through a narrow-band optical filter with a central wavelength of lambda and a proper bandwidth, thus, the laser beam with the wavelength of lambda can be obtained. According to the all-optical wavelength converter, one laser is adopted to synchronously provide the pump source and the converting wavelength, so that the all-optical wavelength converter has the advantages of simple structure, low cost and the like; and moreover, structural parameters of the photonic crystal optical fiber are designed, so that wavelength converting within a larger range can be achieved.

The invention relates to a zinc-oxide piezoresistor raw material, a preparation method thereof and a piezoresistor. The zinc-oxide piezoresistor raw material comprises the following components by mole percent: 91.48-98.03% of zinc oxide, 0.5-2.0% of bismuth trioxide, 0.5-2.5% of silicon dioxide, 0.35-1.5% of cobaltosic oxide, 0.5-1.0% of manganese carbonate, 0.1-0.5% of chromium oxide, 0.01-2.0% of yttria and 0.0001-0.001% of aluminium nitrate. The zinc-oxide piezoresistor raw material does not antimony, and due to the silicon dioxide, the characteristic of the piezoresistor is improved, the surface state density is increased, the voltage gradient, the barrier height and the nonlinear coefficient are improved, the leakage current is reduced and the current impact resistance is enhanced; due to the yttria, the conductivity, the current impact resistance, the nonlinear coefficient and the voltage gradient are improved, the limiting voltage rate and the leakage current are reduced, the grain growth is inhibited and the zinc-oxide piezoresistor has higher voltage gradient and excellent electrical property.

The invention discloses a preparation method of chalcogenide glass tapered fibers. Chalcogenide glass fibers are tapered by the aid of accurate temperature control of a specific electric-heating coil and traction of a precision stepping motor, important parameters such as taper zone lengths, taper zone outer diameters and the like of the tapered fibers are controlled through control on the heating temperature and the tapering traction speed, and the chalcogenide glass tapered fibers with different taper zone lengths and taper zone outer diameters are drawn accurately. The method is simple in technology, high in operability, good in repeatability and high in accuracy and can effectively solve problems that the chalcogenide glass fibers are broken easily during tapering, fiber core diameters and taper zone lengths are difficult to control accurately and the like, the fiber core diameters of the prepared chalcogenide glass tapered fibers with nanoscale or submicron diameters range from 700 mu m to 1,000 mu m, the taper zone lengths range from 3 cm to 7 cm, the production cycle is short, the success rate is high, the chalcogenide glass tapered fibers can be applied to new technical fields of coupling of micro-waveguides, generation of super-continuum spectrum and the like, and research and application fields of the chalcogenide glass tapered fibers are greatly extended.

The invention discloses a crystal material. The crystal material is characterized in that a chemical formula of the crystal material is BaCdSnS4; the crystal material belongs to Fdd2 space groups of orthorhombic crystal systems. The crystal material has the advantages that the crystal material can be used as a nonlinear optical crystal, nonlinear effects of the crystal materials are 1-5 times nonlinear effects of commercial AgGaS2, a laser induced damage threshold of the crystal material is 1-8 times a laser induced damage threshold of the commercial AgGaS2, and the crystal material is a novel intermediate and far infrared nonlinear crystal material with a large nonlinear coefficient and the high laser induced damage threshold.

The invention discloses a middle and low voltage zinc oxide varistor and a preparation method thereof. The varistor is prepared by using ZnO as a main body and adding raw materials of Bi2O3, Co3O4, Sb2O3, MnCO3, Ni2O3, ZrO2, SiO2, SnO2, MgO, TiO2, H3BO3, Al(NO3)3.9H2O, AgNO3 and KNO3. The preparation method is as below: pressing a powder, obtained by milling mixing and granulating on the materials in the formula of the middle and low voltage zinc oxide piezoresistor, into a green blank by a hybrid forming process; and carrying out plastic removal, sintering, screen printing of silver paste, reduction, welding and encapsulation, so as to obtain a middle and low voltage zinc oxide varistor. The preparation process is simple, and the prepared varistor has the advantages of voltage gradient between 80 V / mm to 150 V / mm, small degree of dispersion of varistor voltage, high nonlinear coefficient, good ageing resistance, high energy density, green and environment-friendliness.

The invention relates to a method for manufacturing non-Bi low-voltage ZnO varistor ceramic materials, and belongs to the technology field of an electric component as well as the material manufacture thereof. Zinc oxide is added with the oxide powder of any one from doping elements such as Al, Fe, Eu, Pr, La, Ce, Nd, B, Si, Mn, Cr, Co, Pb, Ti and nanometer ZnO to compose mixed raw materials, the raw materials are mixed, ground, dried, pressed into blocks and pre-sintered at 600 DEG C to 750 DEG C, and then are put into a ball milling pot for being milled, granules are made after the milled material is dried and screened, the powder material is pressed into small round slices which are then heated to 600 DEG C to 720 DEG C for thermal latex exuding, and the low-voltage ZnO varistor ceramic materials can be obtained after the round slices are further sintered and cooled to the room temperature; furthermore, the surface processing and the silver plating are carried out, and the products are encapsulated after being tested, thereby obtaining low-voltage ZnO varistors. The method has the advantages that the manufacturing process is simple; the cost is lower; the performance is good; the application range is wide; the repeatability, the stability and the consistency of the produced varistors are good; the electrical parameter values have obvious improvements and so on.

The invention discloses a method for generating supercontinuum from the communication band to the middle infrared based on a silicon nitride waveguide. The method comprises the steps of step 1, using an ultrashort pulse light source to emit the light which has a frequency of 8-12MHz, and a central wavelength of 1.4-2.2 micrometer, step 2, conducting lens coupling of ultrashort femtosecond pulses which is then infused into a ridge / groove hybrid reverse silicon nitride waveguide with a flat light dispersion, wherein the structure of the silicon nitride waveguide comprises a silica oxide layer arranged on a silicon plate, the grooves containing a single silica ridge is formed on the surface of the silica. The silicon nitride waveguide applies the structure of the ridge / groove hybrid to make the effect area of the light field small, and achieve a big non-linear coefficient of the waveguide. After high peak power femtosecond optical pulses are introduced into the waveguide, non-linear processes of self phase modulation, cross phase modulation, four-wave mixing, soliton frequency shift, dispersive wave generation and the like occur, and finally the supercontinuum from the communication band to the middle infrared is formed.

The invention provides a composite optical fiber with a multi-component phosphate glass cladding / selenium and tellurium compound semiconductor fiber core. A composite optical fiber cladded with semiconductor fiber core glass has great application value in the aspects of nonlinear optical and medium / far infrared optical transmission, optical fiber sensing, photoelectric effect and the like. According to the composite optical fiber with the multi-component phosphate glass cladding / selenium and tellurium compound semiconductor fiber core, experimental study shows that the proper fiber core and cladding materials of the optical fiber with the glass cladding / semiconductor fiber core are obtained, in other words, multi-component phosphate glass is taken as the optical fiber cladding, a semiconductor selenium and tellurium compound is taken as the fiber core of the optical fiber, the thermal properties, the wetting properties and the expansion properties of the materials of the optical fiber cladding and the materials of the fiber core are reasonably combined, and thus the low-loss composite optical fiber which can be drawn continuously is obtained; in addition, the excellent photoelectric properties of the phosphate glass and the selenium and tellurium semiconductor are combined, and the composite optical fiber has broad application prospects in the aspects of optical transmission on the medium / far infrared long-wave band, photoelectric detection, Raman shift infrared sources, optical signal processing based on the high nonlinearity of the optical fiber, super-continuous super-continuum spectrum light sources and the like.

The invention relates to a method for using water-based extending method to prepare multilayer ZnO voltage-sensitive resistance. Wherein, it comprises: using water as solvent to prepare water-based extending slurry; mixing ZnO ceramic, adhesive, disperser, and deion water into water-based extending slurry, while the mass percentage of each component is Zno ceramic at 40-70wt%, adhesive at 3-20w%, disperser at 0.05-2wt%, and the left is deion water; then extending the slurry into ceramic film band; plating one layer of inner electrode; layering, and plating another inner electrode alternative with the last layer; repeating until designed layer number; cutting into plates, adhering and sintering. The invention can reduce cost and apply batch production. And the inventive product has small volume and low cost and applies surface mounting technique.

The invention relates to a high-performance Pr series ZnO voltage sensitive ceramic material and a preparation method thereof, and belongs to the technical field of preparation and application of electronic ceramics. Nano composite ZnO ceramic powder is prepared by wrapping the surface of nano ZnO by a liquid phase deposition method, so that the doped components are mixed uniformly, the micro structure of a product is uniform, the performance of the Pr series ZnO voltage sensitive ceramic material is improved and the sintering temperature of the ceramic material is effectively reduced and the energy consumption is reduced. The Pr series ZnO voltage sensitive ceramic material with high electric potential gradient, a large nonlinear coefficient, and small leakage current is prepared by optimizing the reasonable ratio of all doped components and combining a liquid phase wrapping process, and meets the requirements of high-voltage and supervoltage high-quality arresters and other devices; and the variety of the doped elements for preparing the high-voltage ZnO voltage sensitive ceramic is few, the source of the doped elements is abundant, and the method is simple, so that production cost is lowered.

The invention discloses a zinc oxide resistor disc and a manufacturing method thereof. The zinc oxide resistor disc comprises, by the molar fraction, 95.5% to 99% of zinc oxide base materials, 0.5% to 1.9% of yttrium oxide and 0.5% to 2.6% of zirconium oxide in a sintered mode. The manufacturing method includes the following steps: 1, material dosing; 2, wet grinding pelleting; 3, hydraulic disc forming; 4, segmented sintering. The zinc oxide resistor disc has the advantages of being high in electric potential gradient and large in current flowing capacity; compared with a zinc oxide resistor disc manufactured with a conventional method, the zinc oxide resistor disc manufactured with the manufacturing method has the advantages that the electric potential gradient is increased by near 1 / 4, and the current flowing capacity is improved by 1 / 3.

The invention discloses a photon crystal optical fiber, whose transect includes a fiber core and a cladding. The cladding is identical to the common photon crystal optical fiber, and is a peripheral area surrounding the fiber core and homogeneously distributed with identical structural airports. The airports are periodically arranged in the optical fiber base material, the dimension of the airports is the wavelength magnitude, every three adjacent airport units constitute a regular triangle. The fiber core is jointly constituted by an optical fiber base material locating at the center part of the optical fiber end-face and another solid material, wherein, the refractivity of the solid material is higher than that of the optical fiber base material, two blocks of solid material are symmetric distributed at the both sides of the optical fiber end-face center and the minimum distance of their outer margins should be smaller than 400nm in order to produce a narrow slit. The transect of the solid high-index material may be circular, elliptical shape, square or oblong; the diameter of the circular cross section, the minor axis diameter of the elliptical cross-section, the edge length of the square cross section, and the short edge length of the oblong cross section should be smaller than 400nm. By changing the fiber core structure of the photon crystal optical fiber, the invention uses the narrow slit to limit the light to spread in the nano-scale dimension low refractivity base material, thereby largely decreasing the effective model field area, and causing the photon crystal optical fiber to have ultra-high non-linearity and ultra-low limitation waste. The invention uses a simple and convenient manufacturing structure to resolve the problem in the prior photon crystal optical fiber technique, which is be difficult to implement ultra-high non-linear.

The invention provides a high-nonlinearity dispersion flattened photonic crystal fiber with a pentagonal core. The high-nonlinearity dispersion flattened photonic crystal fiber comprises a quartz glass substrate. Micron-size air holes which are arranged according to certain rules are formed in the substrate, are axially distributed along the fiber and are perforated through the integral fiber; the arrangement rules of the air holes include that the air holes are divided into four layers, the air holes in each layer are arranged to form a regular pentagon, the innermost layer comprises five small air holes, the five small air holes are formed in five vertexes of the corresponding pentagon, and five tiny air holes are additionally formed in positions among the small air holes; the second layer comprises ten large air holes, and five large air holes are formed in five vertexes of the corresponding pentagon; the third layer, namely the second outer layer, comprises fifteen medium air holes, and five medium air holes are respectively formed in five vertexes of the corresponding pentagon; the outermost layer comprises twenty large air holes, and five large air holes are respectively formed in five vertexes of the corresponding pentagon. The high-nonlinearity dispersion flattened photonic crystal fiber has the advantage that requirements of the fields of fiber communication, nonlinear optics, optical signal processing and the like can be effectively met.

The invention relates to a ZnO voltage-sensitive ceramic with a high electric potential gradient and a preparation method of the ZnO voltage-sensitive ceramic. The preparation method comprises the steps: S1, mixing ZnO, Bi2O3, CoO and Mn2O3 according to the molar percentage: 95-99.5, 0.1-2, 0.1-2 and 0.1-2, and then, carrying out wet-type ball milling; S2, carrying out wet-type ball milling for 24h, and then, drying the mixed powder at 80 DEG C for 12 h; S3, dropwise adding 0.5-3 mol / L of acetic acid, carrying out grinding and mixing in a mortar, then, placing the mixture into a metal die forpressing, meanwhile, heating the metal die, carrying out sintering at 250-350 DEG C for 1-3 h, and carrying out natural cooling to obtain the ZnO voltage-sensitive ceramic with the high electric potential gradient. The ZnO voltage-sensitive ceramic is prepared by using cold sintering, so that the sintering temperature is greatly reduced, the preparation method is more energy-saving and environment-friendly, and the electric potential gradient of the obtained ZnO voltage-sensitive ceramic reaches up to 3000 V / mm or above which is about 10 times as high as that of a traditional ZnO voltage-sensitive ceramic.

The invention relates to a titanium oxide multilayer film varistor and a preparation method for the same, and belongs to the technical field of preparation and application of electronic information materials. Nonstoichiometric sintered TiOm is adopted as a substrate target, other metal or oxide thereof is adopted as a doped substrate, and the thin film varistor employing a TiOy-TiOx-TiOy (y is more than x) sandwich structure as a basic unit is prepared in a radio frequency magnetron sputtering way on a conductive substrate with a smooth surface under the action of carrier gas. The thin film varistor prepared by the method is strict and controllable in deposition condition and high in process repeatability, and a thin film with uniform thickness can be obtained on a large-area substrate. The varistor is high in nonlinear performance and controllable in varistor voltage, is particularly suitable for the over-voltage protection of large-scale or super-large-scale integrated circuits, and has broad application prospect in a power system, a communication system, a security system, motor protection, an automotive electronic system, a household electrical appliance and the like.

A method and a device for obtaining flattop Brillouin gain spectra based on pumping modulation in liquid core optical fibers solve the problem in the existing method and device that flattop gain spectra cannot be obtained when adopted dispersion displacement optical fibers or standard single mode optical fibers are over long and equal amplitude pumping wires are fewer and intrinsic Brillouin gain spectra cannot be changed. The method comprises modulating lasers output by a laser to obtain multiple spectral line pumping light, inputting the multiple spectral line pumping light in the liquid core optical fibers, and obtaining the flattop Brillouin gain spectra, namely spectra of backward Brillouin scattering light in the liquid core optical fibers. The device is composed of the laser, a polarization controller, a strength modulator, a signal generator, a direct current DC stabilized power supply, an optical fiber circulator, an optical fiber coupler and the liquid core optical fibers, and another device is composed of a signal generator, an optical fiber circulator, an optical fiber coupler, the liquid core optical fibers and a phase modulator. The method and the device are applicable to obtaining of the flattop Brillouin gain spectra.

The invention discloses an all-optical fiber broadband flat intermediate-infrared super-continuum spectrum light source. The light source is characterized in that the light source comprises a thulium-doped mode-locked fiber laser module used for generating ultra-short pulses, a thulium-doped fiber amplification module used for generating high-power and high-order soliton pulses, a 2-3 micron high-power SC spectrum generation module used for generating 2-3 micron high-power SC spectrum laser, a silica fiber and chalcogenide fiber efficiently-coupled and encapsulated module and a 2-5 micron intermediate-infrared broadband flat SC spectrum generation module for generating a 10dB-bandwidth coverage 2-5 micron intermediate-infrared band broadband flat SC spectrum, wherein the thulium-doped mode-locked fiber laser module, the thulium-doped fiber amplification module, the 2-3 micron high-power SC spectrum generation module, the silica fiber and chalcogenide fiber efficiently-coupled and encapsulated module and the 2-5 micron intermediate-infrared broadband flat SC spectrum generation module are arranged sequentially. According to the light source, quartz optical fiber tapering and lens optical fibers are used in a matched manner, so that efficient coupling of quartz optical fibers and chalcogenide optical fibers can be realized, and pumping efficiency can be improved, the high-quality full-optical fiber broadband flat intermediate-infrared SC (super-continuum spectrum) light source can be realized; since the light source is of a full-optical fiber structure, the intermediate-infrared SC spectrum light source has the advantages of low cost, high conversion efficiency, high-quality output beams and simple and compact structure.

The invention discloses a temperature sensor device based on a chalcogenide glass material and a construction method thereof. The temperature sensor device includes a broadband light source, a first spectrum analyzer and a long-period fiber grating made of a chalcogenide glass material. The two ends of the long-period fiber grating are respectively connected with the broadband light source and thefirst spectrum analyzer. The long-period fiber grating is obtained in a way that a single-mode chalcogenide glass fiber is subjected to fused tapering to form a tapered chalcogenide fiber and the tapered chalcogenide fiber is written in the long-period fiber grating via femtosecond laser pulses. The temperature sense device based on the chalcogenide glass material has a temperature sensitivity of2.97186 nm / DEG C, which is significantly higher than the temperature sensitivity of 0.04-0.1 nm / DEG C of the traditional quartz long-period fiber grating sensor, is more suitable for high-sensitivitytemperature transmission, and has a wider application prospect in the field of high sensitivity sensing.

The invention discloses a surface plasmon polariton (SPP) waveguide with a metal-insulator-semiconductor (MIS) capacitor structure. The SPP waveguide consists of a metal layer (1), an insulating material layer (2), a doped semiconductor layer (3) and a substrate (4), which are arranged from top to bottom, wherein the substrate is grounded through a wire; the metal layer is connected with external voltage through a wire; under proper voltage, a negative real part epsilon r of a complex dielectric function is changed to be positive from an interface of the doped semiconductor layer (3) and the insulating material layer (2) to the interior of the doped semiconductor layer (3), and an area where the epsilon r is negative has characteristics similar to those of metal; an SPP mode can be supported on the interface of the doped semiconductor layer (3) and the insulating material layer (2) and an interface of the positive epsilon r and the negative epsilon r; and the SPP mode supported on the interface of the positive epsilon r and the negative epsilon r is coupled with an SPP mode supported by an interface of the metal layer (1) and the insulating material layer (2) to form a hybrid SPP mode. According to the SPP waveguide, the controllability of a semiconductor can be used for conveniently and efficiently realizing SPP wave regulation and solving a conflict between light field limit and loss.

A Bi-based zinc oxide voltage dependent resistor material is disclosed. The material comprises the following main materials by mole: 93-97% of ZnO, 0.5-1.5% of Bi2O3, 0.5-1.5% of Cr2O3, 0.5-1.5% of Co2O3, 0.5-1.5% of MnCO3, 0.5-1.5% of Sb2O3, and 0.5-1.5% of Al(NO3)3*9H2O. The Bi-based zinc oxide voltage dependent resistor material further comprises La[1-x]Ca[x]MnO[3], wherein x is larger than or equal to 0.6 and smaller than or equal to 0.8; the molar percentage of La[1-x]Ca[x]MnO[3] is 5-40%; and the molar percentage of main materials is 60-95%. The ceramic material provided by the invention has the advantages of high dielectric constant and excellent characteristics of the voltage dependent resistor, and is a composite voltage dependent material with wide application.

The invention discloses a terahertz emission source based on transition metal chalcogenide and an excitation method. The terahertz emission source comprises a transition metal chalcogenide film and pumping light source. The terahertz emission source has the advantages that fixed incoming excitation pulses are used, the planar central axis of the transition metal chalcogenide film is rotated, and pumping light source laser comes in at 0-90 degrees and excite the surface of the transition metal chalcogenide film to radiate terahertz waves; the transition metal chalcogenide film is used as the terahertz emission source, so that the generated terahertz emission source is high in radiation efficiency; in addition, due to the fact that the film is good in heat conductivity, stable in lattice structure and adjustable in energy band gap, device service life and wide application range are guaranteed, and a two-dimensional terahertz emission source type gap is filled up; by using the transitionmetal chalcogenide film as the terahertz emission source, elliptical polarization terahertz waves can be generated, and the elliptical polarization terahertz waves is significant in molecular chirality spectrum, substance circular dichroism spectrum, polarization imaging and the like.

The invention relates to neodymium-doped A3BGa3Si2O14 series crystal, comprising a series crystal of which the chemical formula is A3BGa3Si2O14, wherein A is Ca or Sr; B is Nb or Ta; according to the record, the neodymium-doped A3BGa3Si2O14 series crystal comprises Nd:Ga3TaGa3Si2O14, Nd:Sr3TaGa3Si2O14, Nd:Sr3NbGa3Si2O14 and Nd:Ca3NbGa3Si2O14. The four kinds of crystals can achieve self-frequency-doubling. The invention also provides a method for preparing the neodymium-doped A3BGa3Si2O14 series crystal. The invention also provides an application of the neodymium-doped A3BGa3Si2O14 series crystal. A commercial semiconductor laser pump (LD) of which the center wavelength is 808nm is adopted, gain medium and non-linear optical property of the neodymium-doped A3BGa3Si2O14 (A=Ca, Sr; B=Nb, Ta) series crystal are utilized, so as to obtain a green self-frequency-doubling laser of which the output wavelength is 533nm. The laser device has the advantages of high conversion efficiency, compact structure, miniaturization, high reliability, long service life and the like.

The invention relates to varistor ceramics, and specifically relates to a method for improving the electrical property of a zinc-oxide-based low voltage varister ceramic film. The method is characterized in that: an aluminum foil, which is used as an absorption layer, is attached to the surface of a zinc-oxide-based low voltage varister ceramic film sample; a confinement medium is painted, stuck or covered on the aluminum foil; the ceramic film sample is then embedded on a mold; and laser impact is applied to the ceramic film sample, such that the electrical property of the zinc-oxide-based low voltage varister ceramic film is improved. According to the present invention, a laser impact treatment technology is employed in the surface treatment upon the zinc-oxide-based low voltage varister ceramic film. With the liquid confinement medium, non-linear coefficient of the zinc-oxide-based ceramic film is raised by 24% or above comparing to that before the laser impact treatment, varister voltage of the zinc-oxide-based ceramic film is reduced by 30% or above comparing to that before the laser impact treatment, and leakage current density of the zinc-oxide-based ceramic film is reducedby 35% or above comparing to that before the laser impact treatment. The advantage of the method is that: non-linear coefficient of the film is improved while the leakage current density of the film is reduced.

The invention discloses a method for preparing a silicon-based surface plasma waveguide having a stepped structure in the technical field of nanometer semiconductors. The method comprises the following steps of: coating electron beam photoresist on a silicon-on-insulator (SOI) chip, and forming a waveguide pattern on a silicon layer through an electron beam exposure system and a reactive ion etching system; depositing high-nonlinearity polymer-regional regularity poly(3-hexylthiophene) on an SOI ridge waveguide; removing the electron beam photoresist and the high-nonlinearity polymer-regional regularity poly(3-hexylthiophene) thereon, and depositing the high-nonlinearity polymer-regional regularity poly(3-hexylthiophene) for the second time by a molecular beam deposition method; and plating metal silver on a polymer film by a radio frequency sputtering method, and preparing the silicon-based surface plasma waveguide having the stepped structure. The product has a nano-scale mode field and low transmission loss, and is combined with high-nonlinearity polymer materials to realize super-high nonlinearity.

The invention discloses a high power frequency converter of small core diameter beaming high non-linear photonic crystal fiber, which belongs to a high power ultra continual Laser Technology in the laser field. The converter is composed of a single high power pulse laser, a non-spherical surface collimation beam expander or micro-lens array, the small core diameter beaming high non-linear photonic crystal fiber, a non-spherical surface focusing lens or micro-lens array and big model field photonic crystal fiber. Or the converter is composed of the single high power pulse laser, the non-spherical surface collimation beam expander or micro-lens array, the small core diameter beaming high non-linear photonic crystal fiber and the big model field photonic crystal fiber. The converter of the invention has the advantages of having the ultra continual laser output capacity of above dozens of watt.

The invention relates to a ZnO voltage-sensitive ceramic material and particularly relates to a preparation method of composite nano ZnO voltage-sensitive ceramic powder. The preparation method comprises the following steps: preparing soluble zinc salt, bismuth salt, cobalt salt and manganese salt which are used as raw materials, respectively preparing into aqueous liquor, mixing 95% (in mole percentage) of ZnO, 3% of Bi2O3, 1% of CoO and 1% of MnO, and uniformly stirring; slowly adding ammonia water into mixed liquor obtained in the step (1), regulating the pH to 8-8.5 to obtain mixed liquor, continuously stirring until mixing uniformly; carrying out suction filtration onto precipitates obtained in the step (2), sufficiently washing to remove impurities by using deionized water and alcohol, placing obtained precursor in water or alcohol medium for refluxing for 2-8 hours, and controlling a refluxing temperature to 70 DEG C-80 DEG C; finally, carrying out suction filtration on the powder obtained by refluxing, sufficiently washing to remove impurities by using deionized water and alcohol, finally drying in a vacuum drying box, and grinding to obtain nano composite ZnO powder.