37results about How to "Enhance nonlinear effects" patented technology

The present invention discloses a polarization relevant output multi-wavelength and passive mode-locking optical fiber laser which belongs to laser and light communication field. A ring laser cavity includes Er-doped fiber that is taken as gain medium; a 980nm / 1550nm wavelength-division multiplexer is used to couple pumping laser of 980nm into the Er-doped fiber; a polarization relevant isolator with tail optical fiber on two ends guaranties the laser work in one way, meanwhile plays the role of a polarizer; two polarization controllers respectively on two side of the polarization relevant isolator are used to control polarization state, a 10dB coupler with 10% of the terminal port used to output optical signal and 90% of the optical signal stays in the cavity for cycle. A segment of long single mode fiber is inserted in the laser cavity and used to increase nonlinear effect inside the laser cavity; a piece of polarization maintaining optical fiber and a polarization relevant isolator constitute a birefraction optical fiber periodicity filter; the optical fiber laser is provided with two different output modes, namely mode locking pulse output and multi- wavelength continuous wave output, and can adjust polarization and switch between the two output modes.

The invention relates to an implementation method of a multi-defective one-dimensional photonic crystal all-optical switch with stable and controllable output state; the invention designs a one-dimensional photonic crystal cascade structure, a nonlinear material having higher nonlinear coefficient is added into a linear dielectric layer arrayed periodically, optical switch effect is realized by a broadband detect mode and a narrowband defect mode caused by introducing a multi-defect structure, and the stable control of pump light on the refractive index of a nonlinear medium is realized and the problem that the output state is difficult to be steadily controlled existing in the all-optical switch design is solved simultaneously, thus obtaining the all-optical switch realizing stable performance and quick response time, and providing the method for realizing the all-optical switch for fields such as future all-optical communication networks, optical computers and the like.

Disclosed is a preparation method of a quartz glass-cladding multi-component glass compound optical fiber. According to the preparation method, quartz glass is used as a cladding layer, multi-component glass (phosphate glass, tellurite glass, germanate glass, silicate glass and the like) serves as a fiber core and is drawn to prepare glass fibers, the glass fibers are inserted into quartz glass capillaries with the inner hole size matched with the same and are drawn into the quartz glass-cladding multi-component glass compound optical fiber by heating and cone drawing on an optical fiber conic clink. The preparation method of the quartz glass-cladding multi-component glass compound optical fiber combines the advantage of high strength of the quartz glass and the advantages of high gain, high nonlinearity and the like, the multi-component glass compound optical fiber unusually high in mechanical strength can be prepared, the shortcoming of poor mechanical performance of traditional multi-component glass optical fibers is overcome, and excellent optical performance of the multi-component glass is kept.

The invention relates to the laser field, in particular to a waveguide structured frequency doubler and a manufacturing method thereof. The invention utilizes multiple optical processing, cutting, polishing to manufacture a frequency doubling crystal wafer (or a crystal wafer bonded with a substrate), employs gluing, deepened optical cementing processes to bond the frequency doubling crystal wafer ( or the crystal wafer bonded with the substrate )to the substrate, and then process and polishes the frequency doubling wafer ( or the crystal wafer boned with the substrate ) on the substrate into required dimension of the waveguide structure. The lateral side of the frequency doubling crystal wafer is coated by a low refractive index deepened optical cement layer or glue layer, thereby forming the waveguide structured frequency doubler, wherein the utilized crystal can generate frequency doubling or multiple harmonic wave via critical phase matching, or can generate frequency doubling or higher harmonic wave via non-critical phase matching. The invention overcomes defects of the conventional doublers, and enables optical power density to be much larger than power density of light beams, thereby easily realizing non-linear effect of waveguide materials and further greatly increasing efficiency of the non-linear effect thereof.

The invention discloses a device for generating Q-modulated mode-locked noise square wave pulse. The device comprises a pumping light source, a wavelength division multiplexer, an Er-doped fiber, a first polarization controller, a second polarization controller, a polarization relevant isolator, a fiber coupler and a single-mode fiber, wherein an output end of the pumping light source is connectedwith a first input end of the wavelength division multiplexer, an output end of the wavelength division multiplexer is connected with an input end of the first polarization controller by the Er-dopedfiber, an output end of the first polarization controller is connected with an input end of the fiber coupler by the polarization relevant isolator, a first output end of the fiber coupler is connected with an input end of the second polarization controller by the single-mode fiber, and an output end of the second polarization controller is connected with a second input end of the wavelength division multiplexer. The Q-modulated mode-locked noise square wave pulse is generated by a joint effect of a non-linear polarization rotation effect and a high non-linear effect of a long single-mode fiber. The device can be applied to the field of supercontinuum spectrum generation, microstructure processing, medical treatment and the like.

The invention provides a chalcogenide glass photonic crystal fiber 2*2 interference type all-optical switch which comprises a first coupler, a second couplers, a third coupler, a fourth coupler, a fifth coupler, a sixth coupler, a first chalcogenide glass matrix micro structure fiber, a second chalcogenide glass matrix micro structure fiber, a third chalcogenide glass matrix micro structure fiber, and a plurality of quartz single-mode fibers for connecting the above components. According to the switch, a chalcogenide glass material with a high nonlinearity effect and the photonic crystal fiber technology capable of generating a high nonlinearity effect are combined, a high speed light control 2*2 optical switch device is realized, at the same time, the switch is used as a basic unit to realize an n*n array, and uplink on-off and downlink on-off can be realized simultaneously or respectively.

The invention provides a three-dimensional arrangement nanoparticle film array structure and a preparation method and an application thereof and belongs to the technical field of nano photonics. The preparation method comprises the following steps of coating nano-particles with hydrophobic molecules, and dispersing the coated nano-particles in an organic solvent to obtain a modified nano-particle dispersion liquid; carrying out surface treatment on the three-dimensional template to obtain a hydrophilic three-dimensional template; and adding the water to the surface of the hydrophilic three-dimensional template to form a water film, dropwise adding the modified nanoparticle dispersion liquid to the surface of the water film for self-assembly, and then removing the water film to obtain the three-dimensionally arranged nanoparticle film array structure. The three-dimensional array structure prepared by a self-assembly-template auxiliary method can generate vertical and parallel multi-surface lattice resonance, effectively inhibit radiation loss, enhance interaction between nanoscale light and substances, and have good application prospects in enhancement of nonlinear effect, biosensing, nano laser or enhancement of fluorescence; and the preparation method is good in universality, simple to operate and low in cost.

A layered body comprising: a core region; at least one intermediate layer disposed around the core region; and an outer layer disposed around the at least one intermediate layer, wherein at least one of the at least one intermediate layers comprises a gas, the layered body having at least one dimension, measured across the body and through the core region, of 100 μm or less.

The invention discloses a crystal material, as well as a preparation method and application thereof to a nonlinear optical crystal. The chemical formula of the crystal material is Na2Ga2MQ6, where M represents Ge and / or Sn, and Q represents S and / or Se. The crystal material can be prepared by adopting a high temperature solid state method. The crystal material has high infrared nonlinear optical performance, a nonlinear effect capable of reaching 1.5 times of that of commercial AgGaS2 and a laser damage threshold value capable of reaching 81.5 times of that of the commercial AgGaS2 (which can be abbreviated as AGS). The crystal material has high application value in terms of frequency converters of mid-far infrared band laser frequency multiplication, sum frequency generation, difference frequency generation, optical parametric oscillation and the like.

The invention discloses an underwater acoustic field weak signal enhancement method. The method includes the following steps that: a parametric model of weak signal enhancement is established through utilizing a nonlinear wave equation; the nonlinear parameters of a medium are measured; the frequency and amplitude of weak signals in an acoustic field are estimated; a pump wave generator located at a position d meters before a receiving point R0 emits two columns of pump wave signals of which the angular frequencies are omega 2 and omega 3 respectively, and the energy of pump waves is converted into the energy of weak signal waves in the transmission process of acoustic waves; the amplitude of the pump wave signals is adjusted according to a transmitting-receiving distance d between the pump wave generator and a receiving hydrophone, so that the maximum gain point position of the receiving hydrophone can be consistent with the maximum gain point position of a weak signal enhancement model, and therefore, maximum enhancement of the weak signals can be realized. The enhancement effects of the enhancement method are not limited by array size, and the method is not sensitive to initial acoustic pressure level of signals, and synchronization conditions can be avoided. The enhancement method has strong stability.

The invention discloses a nonlinear optical crystal material Sr3Y3BiB4O15 and a preparation method and application thereof. The crystal material is bismuth yttrium strontium borate shown as the chemical formula of Sr3Y3BiB4O15, belongs to a hexagonal system, and has the space group of P63 and the unit cell parameters of a=10.6975(13)A and c=6.7222(12)A. A crystal structure comprises BO3 radicals which are arranged in accordant direction and a BiO3 radical with lone pair electrons which are arranged in accordant direction, so that nonlinear effect is 3 to 5 times that of KH2PO4. A crystal has moderate hardness, is free from being deliquesced or cleaved, and is easy to cut, polish and store. The crystal grows by a flux growth method. The preparation method comprises the following steps of: mixing bismuth yttrium strontium borate and a fluxing agent; heating the mixture to obtain solution; stirring; preserving heat; cooling until the temperature is 0.5 to 3 DEG C above a saturation point; adding crystal seeds; controlling an appropriate temperature lowering speed; when the crystal grows to a certain degree, extracting the crystal out of a liquid surface; and slowly lowering the temperature to room temperature so as to obtain Sr3Y3BiB4O15 monocrystal. The crystal can serve as a frequency doubling crystal in an optical parametric oscillator and a harmonic generator. Moreover, the crystal comprises a yttrium element, so that other rare earth ions can be doped so as to obtain a self-frequency-doubling laser crystal.

The invention relates to a laser device based on cascaded stimulated scattering. An existing gas Raman laser device is only subjected to one-time SBS and one-time SRS effects, so that the output lightcompression efficiency is low. The invention provides the laser device based on the cascaded stimulated scattering. A first stimulated scattering part comprises a pulse laser device and an SBS compact two-cell assembly; the SBS compact two-cell assembly comprises a first polarization analyzer; a second stimulated scattering part is arranged below the first polarization analyzer; the second stimulated scattering part comprises a first travelling wave amplifier and an SBS focusing single-cell assembly; the SBS focusing single-cell assembly comprises a second polarization analyzer; a third stimulated scattering part is arranged below the second polarization analyzer; the third stimulated scattering part comprises a second travelling wave amplifier and an SRS focusing single-cell assembly; the SRS focusing single-cell assembly comprises a third polarization analyzer; and a light output part is arranged below the third polarization analyzer. The cascaded SBS effect and the travelling waveamplifiers improve the peak power of seed light and improve the SRS effect.

The invention relates to a WDM-PON (Wavelength Division Multiplexing-Passive Optical Network) system based on PS-PAM4 and a WDM-PON system based communication method, which change the distribution probability of each amplitude in a PAM4 signal according to Maxwell-Boltzmann distribution, reduce the nonlinear effect of the signal and realize the transmission with low bit error rate and high receiving sensitivity. According to the invention, the shaping gain can be obtained and the nonlinear effect of the WDM-PON can be improved.

The invention provides an optic frequency doubling or tripling film high in conversion efficiency. The optic frequency doubling or tripling film comprises a unit structure composed of three layers. The upper layer and the lower layer are of metal structures, and the intermediate layer is of a medium structure. A period unit structure is composed of several unit structures, the period is p, and frequency doubling or tripling organic materials are intermediate medium materials. The optic frequency doubling or tripling film has the advantages that size is small, and the metamaterial structure is about 100 nanometers in thickness so that application of the film in the integrated optics is more facilitated; conversion efficiency is high; local electromagnetic field is effectively reinforced by magnetic resonance of the magnetic metamaterial in the structure, and accordingly, nonlinear effect of nonlinear materials is greatly improved, and nonlinear response of the nonlinear material in the same thickness cannot be observed; response speed is fast; metal plasmas can be activated within several femtoseconds, and superfast processing of optic signals is facilitated.

The invention provides a novel nonlinear optical crystal alkali metal NH4Be2BO3F2 and a preparation method and an application of the nonlinear optical crystal alkali metal NH4Be2BO3F2. The general chemical formula of the crystal is (NH4)xM(1-x)Be2BO3F2, AMBBF for short, wherein the range of x is that x is more than 1 and less than 1, and M is chosen from K, Rb and Cs. The series of crystal has nosymmetric center, and belongs to a trigonal system, and the space group is R32. The crystal AMBBF has an excellent optical property, the hydrogen bond between the ion NH4<+> and F<-> in the crystal effectively strengthens the interlayer acting force, and the layered growth habit of the crystal is effectively alleviated; in addition, the c axis of the AKBBF, ARBBF and ACBBF is shortened in comparison with the ABBF, RBBF and CBBF, the nonlinear effect of the crystal is strengthened, the birefringence of the crystal is increased, so that the crystal AMBBF has the advantages of both ABBF and MBBF,particularly, the performance of the AKBBF is almost the same with that of the KBBF, and the interlayer acting force is also improved. The crystal AMBBF meets the use requirement of the nonlinear optical crystal from the infrared spectrum to the deep ultraviolet spectrum.

The invention provides an all-optical switch based on a Period-Double photonic crystal, and belongs to the technical field of all-optical communication. The all-optical switch comprises a plurality of first dielectric layers, a plurality of second dielectric layers and two graphene single layers, the first dielectric layers are marked as H, the second dielectric layers are marked as L, and the graphene single layers are marked as G. The layered structure of the all-optical switch is represented as HL1GL2HH1GH1HL2GL1HL, L1GL2 and L2GL1 both represent three-layer structures formed by embedding the graphene single layers into the second dielectric layers, H1GH1 represents a three-layer structure formed by embedding a graphene single layer into the middle part of the first dielectric layer, the thicknesses of the first dielectric layer and the second dielectric layer are respectively 1 / 4 of respective optical wavelengths, and the first dielectric layer and the second dielectric layer are respectively two uniform dielectric sheets with different refractive indexes. The product can be applied to an all-optical switch.

The invention provides an optical logic device based on a PD photonic crystal and graphene composite structure, and belongs to the technical field of all-optical communication. The composite structure is represented as HLGHHGHHGLH, H and L respectively represent a uniform dielectric sheet I and a uniform dielectric sheet II with different refractive indexes, G is a graphene single layer, and the thickness of the uniform dielectric sheet I and the thickness of the uniform dielectric sheet II are respectively 1 / 4 of the respective optical wavelength. The device has the advantages that the threshold value of the optical bistable state can be reduced, and the like.

The invention discloses a device for generating an ultraviolet super-continuum spectrum light source based on a sub-wavelength optical fiber. The device comprises a pump light source, a first optical fiber coupler and the sub-wavelength optical fiber which are sequentially arranged on the same light path, and the sub-wavelength optical fiber outputs an ultraviolet super-continuum spectrum. The invention discloses a method for generating an ultraviolet super-continuum spectrum light source based on a sub-wavelength optical fiber. The method comprises the following steps: emitting a chirp-free hyperbolic secant light pulse with the central wavelength of 400nm, the initial pulse width range of 250-450fs and the pulse peak power of kilowatt level through a pump light source; an optical pulse enters the sub-wavelength optical fiber through the first optical fiber coupler to carry out dispersion and nonlinear effects, and the sub-wavelength optical fiber outputs an ultraviolet super-continuum spectrum. According to the invention, an ultraviolet super-continuum light source can be generated, and the technical problem that the super-continuum spectrum is difficult to expand to a short wave band is solved.

The invention provides a deep ultraviolet transparent sulfate crystal with ferroelectricity and an optical device. The chemical formula of the sulfate crystal is MxM'yM''z(SO4) (x / 2 + y / 2 + z / 2), wherein M is selected from alkali metal, M' is selected from alkali metal or ammonium ions, and M'' is selected from alkali metal or ammonium ions; and x is greater than or equal to 1, y is greater than or equal to 1, and z is greater than or equal to 0. Periodic polarization is performed on the sulfate crystal by using an electric field to obtain the quasi-phase matching optical device.

The invention relates to an SOI (Silicon On Insulator) wafer with an asymmetric silicon nanoparticle array structure and a preparation method. The SOI wafer comprises a silicon substrate layer, a silicon dioxide buried layer and a silicon nanoparticle array, the nano-particle array is formed by periodically arranging an even number of elements; each element comprises two cuboid nano-particles with different sizes, and the two cuboid nano-particles are arranged in parallel or in a straight line; in the parallel or linear arrangement mode, the first cuboid nano-particles are located on one side of the second cuboid nano-particles; taking a connecting line between the central point of the first cuboid nanoparticle and the central point of the second cuboid nanoparticle as a symmetric axis; and the first cuboid nano-particles and the second cuboid nano-particles are respectively arranged in an axial symmetry manner relative to the symmetry axis. The asymmetric structure adopted by the silicon nanoparticle array enhances the local field intensity of optical signals, the nonlinear combination with the silicon material further enhances the nonlinear effect of the silicon nanoparticle array, and the processing technology is simplified.

A layered body comprising: a core region; at least one intermediate layer disposed around the core region; and an outer layer disposed around the at least one intermediate layer, wherein at least one of the at least one intermediate layers comprises a gas, the layered body having at least one dimension, measured across the body and through the core region, of 100 μm or less.

The invention provides an optical memory based on a Rudin-Chaffino photonic crystal, and belongs to the technical field of all-optical communication. The optical memory comprises a plurality of first dielectric layers, a plurality of second dielectric layers and two graphene single layers, the first dielectric layers are marked as H, the second dielectric layers are marked as L, the graphene single layers are marked as G. The layered structure of the optical memory is represented as HHHLH1GL2HHL2GL1HHLHHH, L1GL2 and L2GL1 both represent three-layer structures formed by embedding the graphene single layers into the second dielectric layers, the thicknesses of the first dielectric layer and the second dielectric layer are respectively 1 / 4 of respective optical wavelengths, and the first dielectric layer and the second dielectric layer are respectively two uniform dielectric sheets with different refractive indexes; the optical memory based on the Ludine-Chaffino photonic crystal can realize a low-threshold optical bistable state, and an upper threshold and a lower threshold of the bistable state respectively correspond to a write-in judgment threshold and a read judgment threshold of the optical memory. The product has the advantages of being applicable to optical memories and the like.

The invention relates to a photon crystal all-optical switch and a design method thereof. The design method is as follows: a multilayer film structure is internally mixed with a center defect layer C or two symmetrical defect layers C and two side detect layers D, wherein N cycles of dielectric films are spaced between the side defect layers D and the defect layers C so as to avoid the mutual coupling of the side defect layers D and the defect layers C; then two detect modules are obtained through adjusting the optical thickness of the center detect layer C or adjusting the optical thickness of the two symmetrical defect layers C and the distance between the two symmetrical defect layers C, and then the optical thickness of the side detect layers D is set to obtain two defect modules withthe Q value ratio of about 2-4; the defect module with the low Q value is set to be a pump light channel, and the defect module with the high Q value is set to be a detection light channel. The invention realizes the all-optical switch with high switching efficiency larger than 90 percent through utilizing the bandgap characteristic of a photon crystal and mixing the nonlinear defect layers, and the needed pump light intensity is about 50 times lower than the condition with a single detect layer and same Q value.

The invention provides a non-linear optical device containing boracite crystals. The non-linear optical device contains the boracite crystals, wherein the boracite crystals are periodically poled. According to the non-linear optical device, after at least one incident electromagnetic radiation is made to pass through at least one boracite crystal, at least one output radiation with the frequency different with that of the incident electromagnetic radiation is generated, wherein the wavelength coverage of the incident electromagnetic radiations is from 0.155 micrometer to 4.0 micrometers. The boracite crystals refer to electro-optical information functional crystals with ferroelectricity and deep ultraviolet nonlinearity, the non-linear optical device made from the boracite crystals can output deep ultraviolet electromagnetic radiations through the quasi-phase matching technology referring to that periodic ferroelectric domain inversion is achieved by using a periodic poling method andapplying impulse voltage to the boracite crystals.

The invention discloses an underwater acoustic field weak signal enhancement method. The method includes the following steps that: a parametric model of weak signal enhancement is established through utilizing a nonlinear wave equation; the nonlinear parameters of a medium are measured; the frequency and amplitude of weak signals in an acoustic field are estimated; a pump wave generator located at a position d meters before a receiving point R0 emits two columns of pump wave signals of which the angular frequencies are omega 2 and omega 3 respectively, and the energy of pump waves is converted into the energy of weak signal waves in the transmission process of acoustic waves; the amplitude of the pump wave signals is adjusted according to a transmitting-receiving distance d between the pump wave generator and a receiving hydrophone, so that the maximum gain point position of the receiving hydrophone can be consistent with the maximum gain point position of a weak signal enhancement model, and therefore, maximum enhancement of the weak signals can be realized. The enhancement effects of the enhancement method are not limited by array size, and the method is not sensitive to initial acoustic pressure level of signals, and synchronization conditions can be avoided. The enhancement method has strong stability.

The invention provides a terahertz wave modulator and a method, and belongs to the technical field of optics. The terahertz modulator comprises a nanostructure layer and a two-dimensional material layer, wherein the nanostructure layer is arranged on one side of the two-dimensional material layer; the nanostructure layer and the two-dimensional material layer are stacked to form a heterojunction; the nanostructure layer comprises a plurality of nanostructures which are periodically arranged; the two-dimensional material layer comprises at least one layer of two-dimensional material with nonlinear conductivity. According to the terahertz modulator provided by the embodiment of the invention, the high-order nonlinear effect of the incident terahertz wave is enhanced for multiple times, and the modulation depth of the terahertz wave is enhanced, so that the nonlinear modulation of the terahertz wave is realized.

The present invention provides a nonlinear optical device, the nonlinear optical device comprises a boronite crystal, wherein the boronite crystal is periodically polarized. The nonlinear optical device is a device that passes at least one beam of incident electromagnetic radiation through at least one boborite crystal to generate at least one beam of output radiation with a frequency different from that of the incident electromagnetic radiation. The wavelength range of the incident electromagnetic radiation is 0.155-4.0 μm. Peroborite crystal is a kind of photoelectric information functional crystal with ferroelectricity and deep ultraviolet nonlinearity. The nonlinear optical device made of peroborite crystal adopts quasi-phase matching technology (the quasi-phase matching is to use periodic pole In this way, the periodic inversion of the ferroelectric domain is realized by applying a pulse voltage to the boraxite crystal), and the output of deep ultraviolet electromagnetic radiation can be realized.