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.

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 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 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 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 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 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 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 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 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.