115results about How to "Adjustable wavelength" patented technology

A doping method for forming quantum dots is disclosed, which includes following steps: providing a first precursor solution for a group II element and a second precursor solution for a group VI element; heating and mixing the first precursor solution and the second precursor solution for forming a plurality of II-VI compound cores of the quantum dots dispersing in a melting mixed solution; and injecting a third precursor solution for a group VI element and a forth precursor solution with at least one dopant to the mixed solution in turn at a fixed time interval in order to form quantum dots with multi-shell dopant; wherein the dopant described here is selected from a group consisting of transitional metal and halogen elements. This method of the invention can dope the dopants in the inner quantum dot and enhance the emission intensity efficiently.

The invention relates to an optical engine for laser projection display of a three-piece liquid crystal on silicon (LCOS). The optical engine comprises a red laser, a green laser, a blue laser, three dodging and reshaping systems, an optical core, a three-piece LCOS, a reflecting mirror and a projection objective, wherein the luminescence centers of the three lasers are positioned on the main optical axes of corresponding dodging and reshaping systems; the three optical axes of corresponding dodging and reshaping systems are parallel with one another; three light beams emitted by the three lasers are adjusted into uniform rectangular parallel light beams by the dodging and reshaping systems respectively; two beams of light directly enter corresponding polarization beam splitters, and the other beam of light is reflected by the reflecting mirror and enters a corresponding polarization beam splitter; and polarized light in three colors is finally combined into white light and enters the projection objective by the optical core. The lasers are taken as light sources, generated laser light is small-bandwidth linear polarized light, and a color filter is not used, so that a large number of polaroids are eliminated, cost is lowered, and the utilization ratio of optical energy is increased simultaneously; and the color gamut range, color brightness degree and color fidelity degree of the optical engine are better than those of the optical engine of the conventional optical system.

The invention relates to a nitrogen oxides luminescent material and a preparation method and an application thereof, belongs to the semiconductor field. The chemical formula of the nitrogen oxides luminescent material is AxByOzN(2/3x+4/3y-2/3z):R, wherein A is one or more of Be, Mg, Ca, Sr, Ba, Zn, Li and Na, and B is one or more of Si, Ge, Zr, Ti, B, Al, Ga and In and contains at least Si. The luminescent material has stable chemical property and excellent luminescent performance, can be used as the blue/green-to-red nitrogen oxides luminescent material of white-light LED which can be excited by ultraviolet LED or blue light LED; the excitation wavelength is 300-500nm, the luminescent wavelength is 470-700nm, and the luminescent material can be used to prepare white light LED lighting sources or display sources by combining the blue light LED or ultraviolet or near-ultraviolet LED.

The invention discloses a scenic area road traffic pollution early-warning device based on a remote sensing technique. Atmospheric laser measurement systems are arranged at measuring points of three to five commanding heights, and all of the atmospheric laser measurement systems are connected to a server; a monitoring result device which is used for detecting the concentration of pollutants of a scenic area road traffic environment air roadside fixed routine monitoring station is connected to the server; a monitoring device of a scenic area combined environment air fixed routine monitoring station is connected to the server; in consideration of various advantages and disadvantages of a current area environment monitoring platform, according to the geographic feature of 'on three sides are cloud-capped hills, on one the busy town' of a West Lake scenic area, NO2 and other chemical substances which are mainly generated by road traffic in the scenic area are monitored in real time by constructing an atmospheric remote sensing and remote measuring platform at the commanding heights around the West Lake.

The invention discloses a silicon-based multifunctional reconfigurable optical filter which comprises a first straight waveguide, a second straight waveguide and a plurality of micro-rings. The micro-rings are connected in parallel through the first straight waveguide and the second straight waveguide. Light field coupling happens between the micro-rings and the two straight waveguides, and no light field coupling happens between the micro-rings. The micro-rings are distributed at equal intervals. The optical filter composed of the micro-rings and the two straight waveguides comprises a plurality of resonant peaks. By controlling the distance of the micro-rings, the phases transmitted and introduced in the straight waveguides between every two adjacent micro-rings by the field with adjacent resonant peak wavelengths are odd times and even times of pi respectively, resonance of different strength is generated for the light field with the adjacent resonant peak wavelengths, and thereforethe optical filter has different filtering characteristics. The filtering functions with different filtering characteristics are achieved through the same filter structure, and it can be ensured thatthe central wavelength and bandwidth of the filter are adjustable.

The invention discloses an external cavity type single-wavelength tunable laser using an FP (Fabry-Perot) laser as a grain light source. The external cavity type single-wavelength tunable laser comprises an FP laser chip; light waveguide is arranged in the FP laser chip; a partial transmission and reflection lens is arranged on the end face of a port for deriving an excitation light source in an optical waveguide port, and a high-reflection membrane is arranged on the end face of the other port; and an optical lens, an optical etalon for carrying out transmission filtering on a transmission light beam of the excitation light source, and a partial reflector for carrying out partial reflection and partial transmission on light beams transmitting the optical etalon are arranged at one side of the port for deriving the excitation light source in the optical waveguide port in sequence. One wavelength peak of the excitation light source is overlapped to one wavelength position of a transmission peak of the optical etalon by changing the distribution of a comb-shaped wavelength wave of the excitation light source, or changing the distribution of the comb-shaped wavelength peak of the excitation light source and the transmission peak of the optical etalon, so that maximum feedback is obtained by a wavelength of a photon at an overlapped position. With the adoption of the external cavity type single-wavelength tunable laser provided by the invention, single-wavelength laser can be output, and a wavelength of output laser can be continuously or selectively changed.

The invention belongs to the technical field of temperature sensors and provides a temperature sensor based on microstructure fibers, the manufacturing method of the temperature sensor, and a temperature measuring device. The temperature sensor comprises at least two microstructure fibers, wherein every two adjacent microstructure fibers are connected in series through a multimode fiber. For a fiber core and a cladding of each microstructure fiber, air holes distributed in the axial direction are formed in the cladding at least. Quantum dot materials are arranged in the air holes. The wavelength of fluorescent light emitted by the quantum dot materials in a microstructure fiber is different from the wavelength of fluorescent light emitted by the quantum dot materials in another microstructure fiber. Compared with ordinary fluorescent materials, the quantum dots have the advantages of being large in excitation wavelength, adjustable in fluorescent wavelength, stable in fluorescent intensity and the like. By adding quantum dots in different types and sizes into the microstructure fibers, the microstructure fibers can be distinguished in a wavelength domain according to the fluorescent wavelengths, and quasi-distributed sensing is realized.

The invention relates to preparation of quantum dots, and discloses a preparation method of thick-shell core-shell quantum dots. A key step is that after quantum dot cores are prepared, an organic phosphine reagent is used for removing metal ions adsorbed on surfaces of the quantum dot cores, wherein the organic phosphine reagent is at least one of tributyl phosphine, triphenyl phosphine, tri-n-octyl phosphine, diphenyl phosphine, and dioctyl phosphine. The invention also discloses an LED containing the quantum dots. The invention provides a simple, convenient and economical method for preparing efficient green light-emitting core-shell quantum dots, and the method, based on an organic phosphine reagent assisted quantum dot extraction purification process, can be used for preparing thick-shell core-shell quantum dots which are controllable in wavelength, narrow in half band width, and high in quantum yield.

The present invention discloses a visible infrared broad band absorber and a preparation method thereof. The device is formed by a multilayer structure consisting of a metal bottom layer, a polymer granular layer, a metal interface layer, a dielectric layer and a metal outer layer in order from a substrate to up. The operating wavelength of the absorber can cover the visible light wave band ( 0.4-0.8[Mu]m) and shortwave infrared band ( 1.1-3[Mu]m), medium wave infrared band ( 3-6[Mu]m) and long wave infrared band ( 6-14[Mu]m). The peak value absorptivity A can reach 99%, and the full width at half-maximum can reach 2[Mu]m. The visible infrared broad band absorber is high in absorption efficiency, wide in operation band and adjustable in wavelength; the visible infrared broad band absorber is not sensitive to incident light polarization and angle; and the visible infrared broad band absorber is simple in technology and low in cost, can perform large-scale preparation and can be grown on a flexible substrate, etc.

The invention provides an organic iridium metal complex, a preparation method thereof and organic electroluminescent devices. The organic iridium metal complex is shown as chemical formula 1, the wavelength of a compound can be adjusted by selecting specific heterocyclic ligand combination, and after the obtained organic iridium metal complex is used for the organic electroluminescent devices, therequired driving voltage of the organic electroluminescent devices is low, and the light-emitting efficiency is improved; the preparation method of the organic iridium metal complex provided by the invention has the advantages of simple synthesis steps, easy product purification, high purity and high yield.

The invention discloses a microwave photonic filter structure capable of realizing complex coefficient. The structure consists of a laser source (101), a light path sequential connection polarization modulator (102), an optical tunable filter (103), an optical coupler (104), an optical adjustable delay line (105), an optical attenuator (106), a polarization beam splitter (107) and a photoelectric detector (108). The structure has the advantages that the microwave photonic filter has the complex coefficient characteristic; and compared with the negative coefficient filter, the free frequency spectrum range is not changed while the central wavelength of the filter can be adjusted. Compared with the scheme of the conventional complex coefficient microwave photonic filter, the structure can be realized only by one light source, so that the cost is reduced. The tunability of the filter can be realized only by changing the polarization detection direction of an optical signal, so that the adjustment is convenient.

The invention relates to a method for preparing a non-periodic optical superlattic titanium diffused waveguide, which belongs to the technical field of laser generators. A titanium diffusion technology is adopted on the -Z surface of a lithium niobate wafer. Pre-splash titanium bars on the -Z surface are diffused inwards to the substrate of the lithium niobate wafer to form a waveguide layer. Then, room-temperature electric field polarization is carried out to change the polarizing direction of the electric domain structure of the lithium niobate wafer, thereby obtaining the titanium diffused waveguide structure. The invention has the advantages that the multi-wavelength laser can stably work at room temperature and is not sensitive to the outside environment; the device is simple and has novel structure and low cost; the method effectively avoids the uniform gain spread effect of doped optical fibers in the traditional multi-wavelength laser; by changing the inputted wavelength of the pumping light, the wavelength or the wavelength interval of the output laser can be flexibly adjusted.

A preparation method of surface crease boron carbon nitride fiber includes the following steps of firstly, putting polyacrylonitrile precursors in a reaction furnace, vacuumizing the reaction furnace and substituting nitrogen, introducing boron trichloride gas or mixed gas of boron trichloride gas and nitrogen, and raising the temperature; secondly, keeping the temperature, and alternately introducing the mixed gas of boron trichloride gas and nitrogen, and mixed gas of ammonia gas and nitrogen; thirdly, raising the temperature; fourthly, cooling the system to the room temperature to obtain the fiber. The fiber has a creased surface, has good mechanical performance, and forms a high contact angle together with water; due to the link structure of the fiber surface, the meshing between the fiber and a base body is enhanced, and the mechanical performance of a fiber enhanced composite can be greatly improved. In addition, the fiber with the surface of the structure has good application prospects on the aspects of controlling surface wettability, manufacturing microfluidic devices and the like.

A LIDAR sensor for detecting an object within a sensing region and a method for activating a LIDAR sensor. The LIDAR sensor includes at least one transmitting unit. The transmitting unit includes at least one source for emitting electromagnetic radiation, and at least one deflection unit for deflecting the electromagnetic radiation emitted by the source into the sensing region along a deflection direction. The transmitting unit further includes at least one transmit filter element for filtering the electromagnetic radiation deflected by the deflection unit, which the electromagnetic radiation strikes along a transmit filter input direction. The transmission behavior of the transmit filter element is a function of the transmit filter input direction.

The invention belongs to the technical field of secret communication, and discloses a Gbps physical key secure distribution system, which comprises a first laser, a second laser, a first semiconductorlaser and a second semiconductor laser; wherein a signal output by the first laser passes through the first polarization controller and the first optical fiber coupler, enters from one end of the single-mode optical fiber, passes through the single-mode optical fiber and the second optical fiber coupler, and is injected into the second semiconductor laser to generate chaotic laser; a signal output by the second laser passes through the second polarization controller and the second optical fiber coupler, enters from the other end of the single-mode optical fiber, passes through the single-modeoptical fiber and the first optical fiber coupler, and is injected into the first semiconductor laser to generate chaotic laser; and then chaotic laser signals output by the first semiconductor laserand the second semiconductor laser are respectively detected by the photoelectric detector and converted into random number sequences by the analog-to-digital converter to be stored in the memory. According to the invention, the security of secret key distribution is ensured, and high-speed physical secret key security distribution is realized.

The invention provides an optical network unit transceiver for a TWDM-PON (Time and Wavelength Division Multiplexed Passive Optical Network) system. The transceiver comprises an optical coupler, a comb filter coupled with the optical coupler, a first optical circulator coupled with the comb filter, an downlink receiver coupled with the first optical circulator, a second optical circulator coupled with the optical coupler and the first optical circulator respectively, and an optical source configured to modulate uplink data into uplink optical signals and output the uplink optical signals.

The invention discloses a white light LED packaging structure and packaging method. The packaging structure comprises a blue light LED chip, a packaging substrate, a light-transmitting carrier, a multilayer-color quantum dot coating layer and a polysiloxane packaging layer, wherein the packaging substrate is used for fixing the blue light LED chip; the packaging substrate comprises a base and a surrounding baffle arranged on the periphery of the base; the blue light LED chip is fixed on the base; the light-transmitting carrier is arranged in the packaging substrate and above the blue light LEDchip; the multilayer-color quantum dot coating layer is arranged on the surface of the light-transmitting carrier; and the polysiloxane packaging layer is arranged on the surface of a protection layer. By virtue of the packaging structure, multi-color quantum dots are mixed to form a warm white light LED which is low in color temperature, high in visual effect and stable.

The invention relates to an adjustable-wavelength emitter (100) for a TWDM-PON. The adjustable-wavelength emitter comprises a multi-mode emitter (110) outputting an optical signal containing multiple longitudinal modes, an optical annular device (120) having a first port used for receiving the optical signal of the multi-mode emitter, a second port used for outputting the optical signal and a third port, and a first micro ring resonator (130) having a first input end used for receiving the optical signal from the second port, a first output end used for outputting a first component of a resonance portion of the optical signal and a second output end used for outputting a second component of the resonance portion of the optical signal, wherein the second output end is connected with the third port of the optical annular device (120).