CN116430515A - Waveguide device based on sulfide and lithium niobate - Google Patents
Waveguide device based on sulfide and lithium niobate Download PDFInfo
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- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 title claims abstract description 147
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 title claims abstract description 70
- 239000010410 layer Substances 0.000 claims abstract description 99
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- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 6
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/353—Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/365—Non-linear optics in an optical waveguide structure
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12035—Materials
- G02B2006/1204—Lithium niobate (LiNbO3)
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B2006/12083—Constructional arrangements
- G02B2006/12097—Ridge, rib or the like
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
The embodiment of the application provides a waveguide device based on sulfide and lithium niobate, and relates to the technical field of integrated optical devices. The waveguide device based on sulfide and lithium niobate comprises a sulfide waveguide loading layer, a thin film lithium niobate layer, a transition layer and a substrate; the thin film lithium niobate layer, the transition layer and the substrate are sequentially laminated along a preset direction, and the thin film lithium niobate layer, the transition layer and the substrate are prepared based on a preset thin film lithium niobate wafer; the sulfide waveguide loading layer is obtained by depositing a preset sulfur material on the surface of the thin film lithium niobate layer, and the sulfide waveguide loading layer and the thin film lithium niobate layer form a core layer of the ridge waveguide, wherein the thin film lithium niobate layer forms a slab layer of the ridge waveguide, and the sulfide waveguide loading layer forms a rib structure of the ridge waveguide. The waveguide device based on sulfide and lithium niobate can achieve the technical effects of reducing transmission loss and improving nonlinear conversion efficiency.
Description
Technical Field
The present application relates to the technical field of integrated optical devices, and in particular, to a waveguide device based on sulfide and lithium niobate.
Background
At present, nonlinear frequency conversion technology utilizing optical second-order nonlinear processes is widely applied in the fields of optical communication, quantum information, physical chemistry, biomedicine and the like. The lithium niobate is an important optical material for nonlinear frequency conversion, and has the advantages of high second-order nonlinear coefficient, wide transparent window, stable chemical property and the like. The traditional nonlinear frequency conversion utilizes lithium niobate crystal to generate new laser frequency, but has the defects of low conversion efficiency, high power consumption, large volume, low integration level and the like. Compared with lithium niobate crystal, the film lithium niobate waveguide has stronger mode field constraint capability, and can effectively improve nonlinear frequency conversion efficiency, reduce device size and reduce energy consumption.
Efficient nonlinear frequency conversion needs to meet phase matching. In a thin film lithium niobate waveguide, the common phase matching modes include quasi-phase matching and mode phase matching, the former needs additional external high-voltage pulse to realize periodic inversion of ferroelectric domain direction of the crystal so as to achieve the phase matching condition, and the latter realizes phase matching by regulating waveguide mode dispersion. The thin film lithium niobate waveguide based on mode phase matching does not need additional periodic polarization processing, and the preparation flow is relatively simple. At present, mode phase matching thin film lithium niobate waveguides are mainly divided into pure lithium niobate waveguides and semi-nonlinear lithium niobate waveguides. The nonlinear frequency conversion efficiency of the pure lithium niobate waveguide is low due to the small mode field overlapping factor, and the nonlinear conversion efficiency of the half nonlinear lithium niobate waveguide is improved by replacing the upper half part of the waveguide core layer with a material without second-order nonlinearity.
In the prior art, lithium niobate is a material with very stable chemical properties, and has great etching difficulty. In the prior research report, although the mode phase matching film lithium niobate waveguide can realize higher length normalization conversion efficiency (the unit is% W - 1 cm -2 ) There are still problems of high transmission loss and low nonlinear conversion efficiency (in%/W). Because the lithium niobate thin film is required to be etched for manufacturing the waveguide, the waveguide loss is generally large, the waveguide length is limited, and the nonlinear conversion efficiency is limited.
Disclosure of Invention
An object of the embodiments of the present application is to provide a waveguide device based on sulfide and lithium niobate, which can achieve the technical effects of reducing transmission loss and improving nonlinear conversion efficiency.
The embodiment of the application provides a waveguide device based on sulfide and lithium niobate, which comprises a sulfide waveguide loading layer, a thin film lithium niobate layer, a transition layer and a substrate;
the thin film lithium niobate layer, the transition layer and the substrate are sequentially stacked along a preset direction, and the thin film lithium niobate layer, the transition layer and the substrate are prepared based on a preset thin film lithium niobate wafer;
the sulfide waveguide loading layer is obtained by depositing a preset sulfur material on the surface of the thin film lithium niobate layer, and the sulfide waveguide loading layer and the thin film lithium niobate layer form a core layer of the ridge waveguide, wherein the thin film lithium niobate layer forms a slab layer of the ridge waveguide, and the sulfide waveguide loading layer forms a rib structure of the ridge waveguide.
In the implementation process, the sulfide and lithium niobate-based waveguide device is characterized in that a preset sulfur material is deposited on the surface of a thin film lithium niobate layer to obtain a sulfide waveguide loading layer, and the sulfide waveguide loading layer and the thin film lithium niobate layer form a ridge waveguide core layer; therefore, the waveguide device based on sulfide and lithium niobate can realize the constraint and phase matching of the optical field in the nonlinear frequency conversion process without etching a lithium niobate wafer, is beneficial to realizing the reduction of waveguide transmission loss and the improvement of nonlinear frequency conversion efficiency, has a simple integration method, and can realize the technical effects of reducing the transmission loss and improving the nonlinear conversion efficiency.
Further, the refractive index of the material of the sulfide waveguide loading layer is higher than that of the material of the thin film lithium niobate layer.
In the implementation process, the refractive index of the material of the sulfide waveguide loading layer is higher than that of the material of the thin film lithium niobate layer, so that the waveguide core layer is beneficial to forming a large refractive index contrast in the whole waveguide, the waveguide forms a small mode field area and has strong mode field constraint capacity, and the nonlinear conversion efficiency is improved.
Further, the predetermined chalcogenide material of the chalcogenide waveguide loading layer does not have second order nonlinearity.
In the implementation process, the preset chalcogenide material of the sulfide waveguide loading layer does not have second-order nonlinearity, so that a semi-nonlinear waveguide is easily formed by the chalcogenide material and lithium niobate having strong second-order nonlinearity.
Further, the sulfide waveguide loading layer is processed into a strip waveguide loading layer through etching.
Further, the waveguide device satisfies type-0 polarization configuration, so that the second-order nonlinear polarization coefficient utilized in the frequency multiplication process of the waveguide device based on the optical second-order nonlinear effect is maximized, and the normalized conversion efficiency of the frequency multiplication process based on the mode phase matching satisfies a preset formula:
wherein, the liquid crystal display device comprises a liquid crystal display device,d 33 is the maximum second-order nonlinear polarizability coefficient of lithium niobate, pi represents the circumference ratio,ωthe frequency is represented by a frequency value,A mode，ω is at the frequency ofωThe effective area of the waveguide mode at the location,A mode，2ω is at frequency 2ωThe effective area of the waveguide mode at the location,ζrepresenting the mode field spatial overlap factor of three waveguide modes in the nonlinear interaction, the three waveguide modes being transverse electric mode, transverse magnetic mode and transverse electric/transverse magnetic mode respectively,A eff represented as a nonlinear effective area of action,cindicating the speed of light in a vacuum,ε 0 indicating the dielectric constant in vacuum,n ω expressed in frequencyωThe effective refractive index of the mode is at,n 2ω expressed at frequency 2ωThe effective refractive index of the mode is at,λ ω expressed in frequencyωAt the wavelength of the light at which the light is emitted,Lrepresenting waveguide length, deltakIndicating the amount of phase mismatch during the frequency doubling process.
Further, the preset formula satisfiesΔk=k 2ω -k ω = 4π/λ(n 2ω -n ω ) =0, i.en 2ω =n ω Wherein, the method comprises the steps of, wherein,k 2ω expressed in frequencyωThe wave number at which the wave number is calculated,k ω expressed in frequencyωThe wave number at which the wave number is calculated,λindicating the wavelength of the preset light wave.
In the implementation process, the efficient SHG is realized in the waveguide based on the mode phase matching mechanism, and the phase mismatch quantity is required to meet the requirementΔk=k 2ω -k ω = 4π/λ(n 2ω -n ω ) =0, i.en 2ω =n ω 。
Further, the waveguide mode of the waveguide device selects a TEM in a communication band 00,tele Mode and visible band TEM 01,vis Mode to achieve mode phase matching, where TEM 00,tele Mode represents TE 00,tele Mode or TM 00,tele Mode, TEM 01,vis Mode represents TE 01,vis Mode or TM 01,vis A mode; where TE represents a transverse electric mode, TM represents a transverse magnetic mode, subscript 00 represents a fundamental mode, subscript 01 represents a first order mode, subscript vis represents a visible light band, and subscript tele represents a communication band.
Further, if the preset thin film lithium niobate wafer is an x-cut or y-cut lithium niobate wafer, the waveguide device configures TE 00,tele Mode and TE 01,vis A mode;
if the preset thin film lithium niobate wafer is a z-cut lithium niobate wafer, the waveguide device is configured with TM 00,tele Mode and TM 01,vis A mode;
wherein, the x-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the x-axis of the crystal, the y-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the y-axis of the crystal, and the z-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the z-axis of the crystal.
Further, the surface of the sulfide waveguide is spin-coated with a polymer cladding.
Further, the surface of the sulfide waveguide is spin-coated with a silicon oxide cladding.
Additional features and advantages of the disclosure will be set forth in the description which follows, or in part will be obvious from the description, or may be learned by practice of the techniques disclosed herein.
In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a waveguide device based on sulfide and lithium niobate according to an embodiment of the present application;
FIG. 2 is a schematic diagram of another waveguide device based on sulfide and lithium niobate according to an embodiment of the present application;
fig. 3 is a schematic diagram showing changes of effective refractive indexes of two modes corresponding to a simulation structure according to an embodiment of the present application along with wavelength changes.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, are intended to be within the scope of the present application.
In the present application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate an azimuth or a positional relationship based on that shown in the drawings. These terms are used primarily to better describe the present application and its embodiments and are not intended to limit the indicated device, element or component to a particular orientation or to be constructed and operated in a particular orientation.
Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in this application will be understood by those of ordinary skill in the art as appropriate.
Furthermore, the terms "mounted," "configured," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or a point connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.
Furthermore, the terms "first," "second," and the like, are used primarily to distinguish between different devices, elements, or components (the particular species and configurations may be the same or different), and are not used to indicate or imply the relative importance and number of devices, elements, or components indicated. Unless otherwise indicated, the meaning of "a plurality" is two or more.
The embodiment of the application provides a waveguide device based on sulfide and lithium niobate, which can be applied to a waveguide of nonlinear frequency conversion, is a novel sulfide-lithium niobate heterogeneous integrated waveguide, and can realize lithium niobate etching-free and low transmission loss and high-efficiency nonlinear frequency conversion; according to the sulfide and lithium niobate-based waveguide device, a preset sulfur material is deposited on the surface of a thin film lithium niobate layer to obtain a sulfide waveguide loading layer, and a ridge waveguide core layer is formed by the sulfide waveguide loading layer and the thin film lithium niobate layer; therefore, the waveguide device based on sulfide and lithium niobate can realize the constraint and phase matching of the optical field in the nonlinear frequency conversion process without etching a lithium niobate wafer, is beneficial to realizing the reduction of waveguide transmission loss and the improvement of nonlinear frequency conversion efficiency, has a simple integration method, and can realize the technical effects of reducing the transmission loss and improving the nonlinear conversion efficiency.
It should be noted that, a waveguide cross-sectional view of a waveguide device based on sulfide and lithium niobate is shown in fig. 2, taking an x-cut commercial lithium niobate wafer as an example, a chalcogenide material is selected from GeSbS, and a waveguide cladding layer is selected from polymer PDMS (Polydimethylsiloxane) to isolate air, so as to prolong the service life of the device. The embodiments illustrate the efficient frequency doubling process (SHG) performance of a lithium niobate wafer-etch-free semi-nonlinear thin film lithium niobate waveguide, but it should be clear that the present application is not limited to waveguide structure designs in this configuration.
Illustratively, when laser light is applied to a second-order nonlinear material, in addition to light (linear portion) having the same frequency as the incident frequency, frequency-doubled light having a frequency of 2 times and an electrostatic field (nonlinear portion) having a frequency of 0 are generated. The resulting multiplied light is referred to as the second order harmonic generation (second-harmonic generation) effect or SHG effect, which is generally used to represent the performance of second order nonlinear materials.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a waveguide device based on sulfide and lithium niobate according to an embodiment of the present application, and fig. 2 is a schematic structural diagram of another waveguide device based on sulfide and lithium niobate according to an embodiment of the present application; the sulfide and lithium niobate based waveguide device includes a sulfide waveguide loading layer 100, a thin film lithium niobate layer 200, a transition layer 300, and a substrate.
Illustratively, the thin film lithium niobate layer 200, the transition layer 300, and the substrate are sequentially stacked in a predetermined direction, and the thin film lithium niobate layer 200, the transition layer 300, and the substrate are prepared based on a predetermined thin film lithium niobate wafer.
By way of example, the pre-set thin film lithium niobate wafer may be a commercial thin film lithium niobate wafer, by way of example only and not limitation.
By optimizing the linear material of the semi-nonlinear waveguide into the chalcogenide material on the basis of the semi-nonlinear waveguide structure system, the waveguide device provided by the embodiment of the application ensures the advantage of high-efficiency nonlinear frequency conversion; secondly, the deposition process of the sulfur-based material is mature and simple, a loading layer which is tightly attached to the lithium niobate wafer is easy to form on the surface of the lithium niobate wafer, and the thickness is uniform and the compactness is excellent; and thirdly, the characteristics of lithium niobate-free etching, easy etching of a chalcogenide material, smooth etching side wall, good verticality, low transmission loss waveguide preparation and the like are combined, so that the heterogeneous integrated waveguide has the advantage of low transmission loss.
Illustratively, the sulfide waveguide loading layer 100 is obtained by depositing a preset sulfide material on the surface of the thin film lithium niobate layer 200, and the sulfide waveguide loading layer 100 and the thin film lithium niobate layer 200 form a core layer of the ridge waveguide, wherein the thin film lithium niobate layer 200 forms a slab layer of the ridge waveguide, and the sulfide waveguide loading layer 100 forms a rib structure of the ridge waveguide; wherein Rib-loaded waveguide: typically, a ridge waveguide is formed of two materials, one of which is a ridge waveguide slab layer and the other of which is a ridge waveguide rib layer.
Illustratively, the sulfide-and lithium niobate-based waveguide device is formed by depositing a preset sulfur material on the surface of the thin film lithium niobate layer 200 to obtain a sulfide waveguide loading layer 100, and forming a ridge waveguide core layer by the sulfide waveguide loading layer 100 and the thin film lithium niobate layer 200; therefore, the waveguide device based on sulfide and lithium niobate can realize the constraint and phase matching of the optical field in the nonlinear frequency conversion process without etching a lithium niobate wafer, is beneficial to realizing the reduction of waveguide transmission loss and the improvement of nonlinear frequency conversion efficiency, has a simple integration method, and can realize the technical effects of reducing the transmission loss and improving the nonlinear conversion efficiency.
Illustratively, the refractive index of the material of the sulfide waveguide loading layer is higher than the refractive index of the material of the thin film lithium niobate layer.
Illustratively, the refractive index of the material of the sulfide waveguide loading layer is higher than that of the material of the thin film lithium niobate layer, so that the waveguide core layer forms large refractive index contrast in the whole waveguide, the waveguide forms a small mode field area and has strong mode field constraint capability, and the nonlinear conversion efficiency is improved.
Illustratively, the predetermined chalcogenide material of the chalcogenide waveguide loading layer does not possess a second order nonlinearity.
Illustratively, the predetermined chalcogenide material of the chalcogenide waveguide loading layer does not possess a second order nonlinearity, and thus readily constitutes a semi-nonlinear waveguide with lithium niobate possessing a strong second order nonlinearity.
In some implementations, the chalcogenide material selected for the sulfide-and lithium niobate-based waveguide device is Ge 25 Sb 10 S 65 (GeSbS)、As 2 S 3 And the like, but are not limited to these two materials, as long as the following conditions are satisfied: the refractive index of the material is higher than that of the lithium niobate material, so that the waveguide core layer is favorable for forming large refractive index contrast in the whole waveguide, so that the waveguide forms a small mode field area and has strong mode field constraint capability, and the nonlinear conversion efficiency is improved; secondly, the selected material does not have second-order nonlinearity, and is easy to form a semi-nonlinear waveguide with lithium niobate having strong second-order nonlinearity; thirdly, the selected material has the advantages of simple deposition and low etching difficulty, and the waveguide device with low transmission loss is conveniently prepared.
Illustratively, the sulfide waveguide loading layer is fabricated into a strip waveguide loading layer by etching.
Illustratively, for ease of discussion of nonlinear frequency conversion efficiency, the present embodiments are described with the aid of a frequency doubling process (SHG) based on optical second order nonlinear effects, but it is noted that the waveguide design is equally applicable to other nonlinear frequency conversion processes based on optical second order nonlinear effects, such as sum and difference frequencies.
In a thin film lithium niobate waveguide, to maximize the second order nonlinear polarization coefficient utilized by its SHG, a mode with extraordinary light (e-light) as the main polarization needs to be selected, i.e., a type-0 polarization configuration is satisfied.
Illustratively, the waveguide device satisfies a type-0 polarization configuration, so that a second-order nonlinear polarization coefficient utilized in a frequency multiplication process of the waveguide device based on an optical second-order nonlinear effect takes a maximum value, and a normalized conversion efficiency of the frequency multiplication process based on mode phase matching satisfies a preset formula:
wherein, the liquid crystal display device comprises a liquid crystal display device,d 33 is the maximum second-order nonlinear polarizability coefficient of lithium niobate, pi represents the circumference ratio,ωthe frequency is represented by a frequency value,A mode，ω is at the frequency ofωThe effective area of the waveguide mode at the location,A mode，2ω is at frequency 2ωThe effective area of the waveguide mode at the location,ζthe mode field spatial overlap factor representing three waveguide modes in the nonlinear interaction, transverse electric mode (TE), transverse magnetic mode (TM) and transverse electric/transverse magnetic mode (TEM), respectively,A eff represented as a nonlinear effective area of action,cindicating the speed of light in a vacuum,ε 0 indicating the dielectric constant in vacuum,n ω expressed in frequencyωThe effective refractive index of the mode is at,n 2ω expressed at frequency 2ωThe effective refractive index of the mode is at,λ ω expressed in frequencyωAt the wavelength of the light at which the light is emitted,Lrepresenting waveguide length, deltakIndicating the amount of phase mismatch during the frequency doubling process.
Illustratively, efficient SHG conversion efficiency requires a nonlinear effective area of actionA eff As small as possible, smallerA eff It is required that the overlap factor of the two modes is as large as possible.
Illustratively, the preset formula satisfiesΔk=k 2ω -k ω = 4π/λ(n 2ω -n ω ) =0, i.en 2ω =n ω Wherein, the method comprises the steps of, wherein,k 2ω expressed in frequencyωThe wave number at which the wave number is calculated,k ω expressed in frequencyωThe wave number at which the wave number is calculated,λindicating the wavelength of the preset light wave.
Illustratively, implementing efficient SHG in a waveguide based on a mode phase matching mechanism requires that its amount of phase mismatch be satisfiedΔk=k 2ω -k ω = 4π/λ(n 2ω -n ω ) =0, i.en 2ω =n ω 。
Illustratively, the waveguide mode of the waveguide device selects a TEM in the communications band 00,tele Mode and visible band TEM 01,vis Mode to achieve mode phase matching, where TEM 00,tele Mode represents TE 00,tele Mode or TM 00,tele Mode, TEM 01,vis Mode represents TE 01,vis Mode or TM 01,vis A mode; where TE represents a transverse electric mode, TM represents a transverse magnetic mode, subscript 00 represents a fundamental mode, subscript 01 represents a first order mode, subscript vis represents a visible light band, and subscript tele represents a communication band.
Exemplary, phase matching conditions in a mode phase matching mechanism in combination with a semi-nonlinear waveguide structure distributed up and down in FIG. 1n 2ω =n ω It will be appreciated that the waveguide modes mentioned should be selected from TEMs in the communications band 00,tele Mode and visible band TEM 01,vis Pattern to achieve pattern phase matching: the adjacent order modes of different wave bands have the condition of realizing equal effective refractive indexes, and the mode field space overlapping factors of the adjacent order modes
The maximum is possible.
Exemplary, if the predetermined thin film lithium niobate wafer is an x-cut or y-cut lithium niobate wafer, the waveguide device configures TE 00,tele Mode and TE 01,vis A mode;
if the preset thin film lithium niobate wafer is a z-cut lithium niobate wafer, the waveguide device is configured with TM 00,tele Mode and TM 01,vis A mode;
wherein, the x-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the x-axis of the crystal, the y-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the y-axis of the crystal, and the z-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the z-axis of the crystal.
Illustratively, the crystal structure of lithium niobate belongs to a trigonal system, so that the thin film lithium niobate wafer can be processed into three crystal orientation cutting modes of x-cut, y-cut and z-cut, wherein x, y and z respectively represent vertical cutting along corresponding coordinate axes of the crystal.
Illustratively, since lithium niobate is a birefringent trigonal system, the manner in which thin film lithium niobate wafers are cut is divided into x-cut, y-cut and z-cut thin film lithium niobate wafers by an angle with the principal optical axis of the crystal;
for the x-cut/y-cut lithium niobate wafer, TE should be selected 00,tele Mode and TE 01,vis A mode; for a z-cut lithium niobate wafer, TM should be selected 00,tele Mode and TM 01,vis A mode.
Illustratively, the surface of the sulfide waveguide is spin coated with a polymer cladding 400.
Illustratively, the surface of the sulfide waveguide is spin-on deposited with a silica cladding.
Illustratively, it may be determined whether to choose spin-on polymer cladding 400 or deposit a silicon oxide cladding according to practical conditions (e.g., difficulty in process implementation, adjustment of phase matching wavelength).
In some embodiments, as shown in fig. 2, the processing pretreatment before depositing GeSbS is performed on the lithium niobate wafer with the thickness of 400 nm, which mainly plays roles of cleaning the surface of the wafer and improving the close fit with the subsequent deposition of the loading layer material; then, depositing a compact and high-purity GeSbS film with different thicknesses of 150-200 nm on the surface of the wafer by a vacuum thermal evaporation method, wherein the different thicknesses only affect the phase matching wavelength in the waveguide SHG, and etching the GeSbS film layer into a GeSbS strip waveguide; and finally spin-coating PDMS polymer with the thickness of 3-5 um as a waveguide cladding.
Referring to fig. 3, fig. 3 is a schematic diagram showing that effective refractive indexes of two modes corresponding to the simulation structure provided in the embodiment of the present application change with wavelength.
Illustratively, two modes TE in a waveguide device are utilized with the waveguide structure shown in fig. 2 00,tele And TE (TE) 01,vis The process of achieving the phase matching condition is shown in fig. 3. Based on the phase matching wavelength, SHG normalized conversion efficiency calculation is carried out on the waveguide structure to obtain nonlinear effective acting areaA eff = 7.4 um 2 Mode field spatial overlap factor
=0.5, normalized conversion efficiency 1400% W -1 cm -2 A level.
In some embodiments, the normalized conversion efficiency of the waveguide structure as shown in FIG. 2 stays at more than 1400% W -1 cm -2 A level; if TE is utilized 01,vis Mode is hybridized with linear material layer, and the mode light field is destroyed to distribute the linear material layer and the nonlinear material layer, namely TE 01,vis The light field of the half-mode is mainly confined to the thin film lithium niobate layer, thereby increasing the mode field overlap factor, e.g. the overlap factor in this embodiment
The conversion efficiency can reach the improvement of multiple stages by increasing the conversion rate to 0.9.
By way of example, the waveguide device based on sulfide and lithium niobate provided by the embodiment of the application realizes excellent performances such as lithium niobate-free wafer etching, low transmission loss, high-efficiency nonlinear wavelength conversion efficiency and the like on the premise of keeping the advantages of miniaturization, easiness in integration and the like of a semi-nonlinear thin film lithium niobate waveguide; the nonlinear conversion efficiency can be compared with a semi-nonlinear waveguide scheme which needs a high-quality lithium niobate etching structure, and meanwhile, the thin film lithium niobate device with the centimeter-level length advantage can be prepared by utilizing the low-loss characteristic.
In all embodiments of the present application, "large" and "small" are relative terms, "more" and "less" are relative terms, "upper" and "lower" are relative terms, and the description of such relative terms is not repeated herein.
It should be appreciated that reference throughout this specification to "in this embodiment," "in an embodiment of the application," or "as an alternative" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. Thus, the appearances of the phrases "in this embodiment," "in this application embodiment," or "as an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Those skilled in the art will also appreciate that the embodiments described in the specification are all alternative embodiments and that the acts and modules referred to are not necessarily required in the present application.
In various embodiments of the present application, it should be understood that the size of the sequence numbers of the above processes does not mean that the execution sequence of the processes is necessarily sequential, and the execution sequence of the processes should be determined by the functions and internal logic thereof, and should not constitute any limitation on the implementation process of the embodiments of the present application.
The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (10)
1. A waveguide device based on sulfide and lithium niobate, which is characterized by comprising a sulfide waveguide loading layer, a thin film lithium niobate layer, a transition layer and a substrate;
the thin film lithium niobate layer, the transition layer and the substrate are sequentially stacked along a preset direction, and the thin film lithium niobate layer, the transition layer and the substrate are prepared based on a preset thin film lithium niobate wafer;
the sulfide waveguide loading layer is obtained by depositing a preset sulfur material on the surface of the thin film lithium niobate layer, and the sulfide waveguide loading layer and the thin film lithium niobate layer form a core layer of the ridge waveguide, wherein the thin film lithium niobate layer forms a slab layer of the ridge waveguide, and the sulfide waveguide loading layer forms a rib structure of the ridge waveguide.
2. The sulfide and lithium niobate based waveguide device of claim 1, wherein the refractive index of the material of the sulfide waveguide loading layer is higher than the refractive index of the material of the thin film lithium niobate layer.
3. The sulfide and lithium niobate based waveguide device of claim 1 or 2, wherein the pre-set chalcogenide material of the sulfide waveguide loading layer is free of second order nonlinearity.
4. The sulfide and lithium niobate based waveguide device of claim 1, wherein the sulfide waveguide loading layer is processed into a strip waveguide loading layer by etching.
5. The sulfide and lithium niobate based waveguide device of claim 1, wherein the waveguide device satisfies a type-0 polarization configuration such that a second order nonlinear polarization coefficient utilized in a frequency multiplication process of the waveguide device based on an optical second order nonlinear effect takes a maximum value, and a frequency multiplication process normalization conversion efficiency based on mode phase matching satisfies a preset formula:
wherein, the liquid crystal display device comprises a liquid crystal display device,d 33 is the maximum second-order nonlinear polarizability coefficient of lithium niobate, pi represents the circumference ratio,ωthe frequency is represented by a frequency value,A mode，ω is at the frequency ofωThe effective area of the waveguide mode at the location,A mode，2ω is at frequency 2ωThe effective area of the waveguide mode at the location,ζmode field spatial overlap factor representing three waveguide modes in nonlinear interaction, namely transverse electric mode, transverse magnetic mode and transverse electric/transverse magnetic mode respectivelyThe method comprises the steps of,A eff represented as a nonlinear effective area of action,cindicating the speed of light in a vacuum,ε 0 indicating the dielectric constant in vacuum,n ω expressed in frequencyωThe effective refractive index of the mode is at,n 2ω expressed at frequency 2ωThe effective refractive index of the mode is at,λ ω expressed in frequencyωAt the wavelength of the light at which the light is emitted,Lrepresenting waveguide length, deltakIndicating the amount of phase mismatch during the frequency doubling process.
6. The sulfide and lithium niobate based waveguide device of claim 5, wherein the predetermined formula satisfiesΔk = k 2ω -k ω = 4π/λ(n 2ω -n ω ) =0, i.en 2ω = n ω Wherein, the method comprises the steps of, wherein,k 2ω expressed in frequencyωThe wave number at which the wave number is calculated,k ω expressed in frequencyωThe wave number at which the wave number is calculated,λindicating the wavelength of the preset light wave.
7. The sulfide and lithium niobate based waveguide device of claim 6, wherein the waveguide mode of the waveguide device selects a TEM in the communication band 00,tele Mode and visible band TEM 01,vis Mode to achieve mode phase matching, where TEM 00,tele Mode represents TE 00,tele Mode or TM 00,tele Mode, TEM 01,vis Mode represents TE 01,vis Mode or TM 01,vis A mode; where TE represents a transverse electric mode, TM represents a transverse magnetic mode, subscript 00 represents a fundamental mode, subscript 01 represents a first order mode, subscript vis represents a visible light band, and subscript tele represents a communication band.
8. The sulfide and lithium niobate based waveguide device of claim 7, wherein if the pre-set thin film lithium niobate wafer is a lithium niobate wafer of x-cut or y-cut, the waveguide device configures TE 00,tele Mode and TE 01,vis A mode;
if the preset thin film lithium niobate wafer is a z-cut lithium niobate wafer, the waveguide device is configured with TM 00,tele Mode and TM 01,vis A mode;
wherein, the x-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the x-axis of the crystal, the y-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the y-axis of the crystal, and the z-cut lithium niobate wafer is represented as a thin film lithium niobate wafer vertically cut along the z-axis of the crystal.
9. The sulfide and lithium niobate based waveguide device of claim 1, wherein the surface of the sulfide waveguide is spin coated with a polymer cladding.
10. The sulfide and lithium niobate based waveguide device of claim 1, wherein the surface of the sulfide waveguide is spin-on deposited with a silica cladding.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0764034A (en) * | 1993-08-23 | 1995-03-10 | Ibiden Co Ltd | Travelling wave type optical modulator |
| CN1564036A (en) * | 2004-03-18 | 2005-01-12 | 上海理工大学 | Arsenium sulfide-lightium niobate compounded waveguide coupler |
| CN108919420A (en) * | 2018-07-17 | 2018-11-30 | 宁波大学 | A kind of sulphur system waveguiding structure applied to middle infrared band |
| CN109975926A (en) * | 2019-03-20 | 2019-07-05 | 山东大学 | A kind of silica load strip waveguide and preparation method thereof |
| CN110133802A (en) * | 2019-06-13 | 2019-08-16 | 天津领芯科技发展有限公司 | A kind of novel lithium niobate optical waveguide wafer and preparation method thereof |
| CN113204134A (en) * | 2021-05-13 | 2021-08-03 | 暨南大学 | Novel high-efficiency on-chip mid-infrared acousto-optic modulator and preparation method thereof |
| CN113311636A (en) * | 2021-05-08 | 2021-08-27 | 南京邮电大学 | Method for generating second harmonic in lithium niobate waveguide structure |
| CN114325939A (en) * | 2020-09-30 | 2022-04-12 | 住友大阪水泥股份有限公司 | Optical waveguide element, and optical modulation device and optical transmission device using the same |
| CN115951449A (en) * | 2023-03-13 | 2023-04-11 | 中科鑫通微电子技术(北京)有限公司 | Low-loss lithium niobate waveguide and preparation method thereof |
-
2023
- 2023-04-17 CN CN202310404222.9A patent/CN116430515B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0764034A (en) * | 1993-08-23 | 1995-03-10 | Ibiden Co Ltd | Travelling wave type optical modulator |
| CN1564036A (en) * | 2004-03-18 | 2005-01-12 | 上海理工大学 | Arsenium sulfide-lightium niobate compounded waveguide coupler |
| CN108919420A (en) * | 2018-07-17 | 2018-11-30 | 宁波大学 | A kind of sulphur system waveguiding structure applied to middle infrared band |
| CN109975926A (en) * | 2019-03-20 | 2019-07-05 | 山东大学 | A kind of silica load strip waveguide and preparation method thereof |
| CN110133802A (en) * | 2019-06-13 | 2019-08-16 | 天津领芯科技发展有限公司 | A kind of novel lithium niobate optical waveguide wafer and preparation method thereof |
| CN114325939A (en) * | 2020-09-30 | 2022-04-12 | 住友大阪水泥股份有限公司 | Optical waveguide element, and optical modulation device and optical transmission device using the same |
| CN113311636A (en) * | 2021-05-08 | 2021-08-27 | 南京邮电大学 | Method for generating second harmonic in lithium niobate waveguide structure |
| CN113204134A (en) * | 2021-05-13 | 2021-08-03 | 暨南大学 | Novel high-efficiency on-chip mid-infrared acousto-optic modulator and preparation method thereof |
| CN115951449A (en) * | 2023-03-13 | 2023-04-11 | 中科鑫通微电子技术(北京)有限公司 | Low-loss lithium niobate waveguide and preparation method thereof |
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