CN116859510B - Waveguide array structure and optical field regulating and controlling method thereof - Google Patents
Waveguide array structure and optical field regulating and controlling method thereof Download PDFInfo
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- 230000033228 biological regulation Effects 0.000 claims abstract description 48
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Classifications
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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
- G02B6/122—Basic optical elements, e.g. light-guiding paths
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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
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29331—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by evanescent wave coupling
- G02B6/29335—Evanescent coupling to a resonator cavity, i.e. between a waveguide mode and a resonant mode of the cavity
- G02B6/29338—Loop resonators
- G02B6/2934—Fibre ring resonators, e.g. fibre coils
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- 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
- G02F1/01—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 for the control of the intensity, phase, polarisation or colour
- G02F1/011—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 for the control of the intensity, phase, polarisation or colour in optical waveguides, not otherwise provided for in this subclass
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- 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
- G02F1/01—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 for the control of the intensity, phase, polarisation or colour
- G02F1/21—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 for the control of the intensity, phase, polarisation or colour by interference
- G02F1/212—Mach-Zehnder type
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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
- G02B2006/12133—Functions
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Abstract
The application provides a waveguide array structure and an optical field regulation method thereof. The waveguide array structure is used for on-chip optical wavefront shaping. The waveguide array structure comprises at least one stage of waveguide array, the waveguide array comprises a substrate layer, a buffer layer, a waveguide layer and a covering layer which are sequentially stacked from bottom to top, and the waveguide layer comprises a plurality of waveguides which are arranged at intervals. The regulation and control parameters of the effective refractive index of the optical mode in the waveguide array along the light transmission direction meet the effective refractive index distribution function, the center-to-center distance parameters of two adjacent waveguides meet the center-to-center distance distribution function, and the optical wave front of the light is shaped after the light passes through at least one waveguide array. The on-chip optical wavefront shaping function is realized, and the on-chip optical wavefront shaping method has important application value for on-chip optical signal processing, especially for application scenes of high integration density and multiple optical channels, and can realize functions of on-chip optical field focusing, diffraction-free transmission, optical field regulation and control and the like.
Description
Technical Field
The application relates to the technical field of integrated photoelectrons, in particular to a waveguide array structure and a light field regulation method thereof.
Background
At present, the optical wavefront shaping has important application value in the fields of basic physical research, information processing, optical imaging, laser radar and the like, the on-chip optical wavefront shaping technology can enrich the application scene of an integrated optical system, and the development of the related technology has important significance in the application of integrated photon information processing and the like. In order to realize wavefront regulation of an optical field transmitted on a chip, two main solutions at present are respectively based on a metamaterial system with a sub-wavelength scale and a waveguide system with a non-uniform thickness, and the two solutions have the problems of large process implementation difficulty and low tolerance and are not easy to be compatible with an integrated photon device based on an optical waveguide structure. In contrast, waveguide systems compatible with micro-nano fabrication processes are a more ideal option for modulating on-chip optical wavefronts. The optical waveguide is the most basic and universal structure of the integrated photon platform, and the related design, preparation and sealing technology are very mature and can be well compatible with various integrated photon devices. However, there are difficulties in achieving wavefront shaping in the relevant waveguide systems.
Disclosure of Invention
The application provides a waveguide array structure for realizing an on-chip optical wavefront shaping function and a light field regulating and controlling method thereof.
The application provides a waveguide array structure which is used for on-chip optical wavefront shaping and comprises at least one stage of waveguide array, wherein the waveguide array comprises a substrate layer, a buffer layer, a waveguide layer and a covering layer which are sequentially stacked from bottom to top, and the waveguide layer comprises a plurality of waveguides which are arranged at intervals; the regulation and control parameters of the effective refractive index of the optical mode in the waveguide array along the light transmission direction meet the effective refractive index distribution function, and the center-to-center distance parameters of two adjacent waveguides meet the center-to-center distance distribution function; the optical wavefront of the light is shaped after it passes through at least one of the waveguide arrays.
Optionally, the regulation parameters include materials of the buffer layer, the waveguide layer and the cover layer; the width of the waveguide; the thickness of the waveguide layer; the etching depth of the waveguide layer; the waveguide layer transmits the wavelength of light; the polarization state of the optical field transmission of the waveguide layer and the mode of the optical field transmission of the waveguide layer.
Optionally, the effective refractive index distribution function includes a hyperbolic secant distribution function or a quadratic distribution function.
Optionally, the inter-center distance distribution function includes a hyperbolic secant distribution function or a quadratic distribution function.
Optionally, the waveguide array structure further comprises an optical modulator; the waveguide array structure further comprises an input waveguide arranged at the input end of the waveguide array and an output waveguide arranged at the output end of the waveguide array, and the optical modulator is arranged at the input waveguide.
Optionally, the optical modulator includes at least one of a waveguide phase shifter, a mach-zehnder interferometer, a ring resonator.
Optionally, the number of the optical modulators is set to at least one.
Optionally, the number of the optical modulators is one, and the input waveguide of the waveguide array structure is one of the waveguide phase shifter, the mach-zehnder interferometer, and the ring resonator.
Optionally, the number of the optical modulators is two, and the input waveguide of the waveguide array structure is provided with two of the waveguide phase shifter, the mach-zehnder interferometer and the ring resonator.
Optionally, the number of the optical modulators is three, and the input waveguide of the waveguide array structure is provided with the waveguide phase shifter, the mach-zehnder interferometer and the ring resonator.
Optionally, the waveguide array structure includes a multistage waveguide array, in the optical transmission direction of the waveguide array, the waveguide array at the previous stage is cascade-connected with the waveguide array at the next stage through the output waveguide connected to the output end of the waveguide array and the input waveguide connected to the input end of the waveguide array at the next stage; the optical wavefront of the light passing through the multi-stage waveguide array is shaped in multiple stages.
Optionally, the number of the optical modulators is set to at least one; at least one of the optical modulators is disposed in the cascade-connected multistage waveguide array in the input waveguide connected to the input end of at least one of the waveguide arrays.
The application also provides a light field regulation and control method of the waveguide array structure, wherein the waveguide array structure is used for on-chip optical wavefront shaping; the waveguide array structure comprises a waveguide array, wherein the waveguide array comprises a plurality of waveguides; the optical field regulation and control method of the waveguide array structure comprises the following steps:
setting a regulation parameter of an effective refractive index of an optical mode in the waveguide array along the light transmission direction of the optical mode, so that the effective refractive index meets the effective refractive index distribution function;
Setting center-to-center distance parameters of two adjacent waveguides to enable the center-to-center distance parameters to meet the center-to-center distance distribution function;
determining a diffraction coefficient of the waveguide array along the light transmission direction according to the regulation and control parameters of the effective refractive index and the center-to-center distance parameters of two adjacent waveguides; and
And regulating and controlling the optical field of the optical mode in the waveguide array along the light transmission direction according to the diffraction coefficient.
Optionally, the determining the diffraction coefficient of the waveguide array along the light transmission direction of the waveguide array according to the regulation parameter of the effective refractive index and the center-to-center distance parameter of two adjacent waveguides includes:
when the diffraction coefficient is determined to be positive and/or negative along the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is diffraction; or (b)
When the diffraction coefficient is determined to be zero along the light transmission direction of the waveguide array, the incident optical wavefront is not diffracted in the waveguide array.
Optionally, when determining that the diffraction coefficient is positive and/or negative along the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is diffraction, including:
When the diffraction coefficient is determined to be positive in the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is abnormal diffraction; or (b)
When the diffraction coefficient is determined to be negative in the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is normal diffraction.
Optionally, when determining that the diffraction coefficient is positive and/or negative along the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is diffraction, including:
when it is determined that the diffraction coefficient has positive and negative values along the light transmission direction of the waveguide array, and the integral of the diffraction coefficient along the light transmission direction of the waveguide array is zero, the transmission form of the incident optical wavefront in the waveguide array is self-focusing; or (b)
When it is determined that the diffraction coefficient has positive and negative values along the light transmission direction of the waveguide array, the integral of the diffraction coefficient along the light transmission direction of the waveguide array is zero, and the effective refractive index of the optical mode in the waveguide array satisfies the effective refractive index distribution function, the transmission form of the incident optical wavefront in the waveguide array is a transmission form through a lens.
Optionally, the waveguide array includes a substrate layer, a buffer layer, a waveguide layer and a cover layer that are sequentially stacked from bottom to top, where the waveguide layer includes a plurality of waveguides that are disposed at intervals; the regulation parameters comprise materials of the buffer layer, the waveguide layer and the cover layer; the width of the waveguide; the thickness of the waveguide layer; the etching depth of the waveguide layer; the waveguide layer transmits the wavelength of light; the polarization state of the optical field transmission of the waveguide layer and the mode of the optical field transmission of the waveguide layer.
Optionally, the effective refractive index distribution function includes a hyperbolic secant distribution function or a quadratic distribution function.
Optionally, the inter-center distance distribution function includes a hyperbolic secant distribution function or a quadratic distribution function.
The waveguide array structure and the optical field regulation and control method thereof are provided. The waveguide array structure is used for on-chip optical wavefront shaping. The waveguide array structure comprises at least one stage of waveguide array, the waveguide array comprises a substrate layer, a buffer layer, a waveguide layer and a covering layer which are sequentially stacked from bottom to top, and the waveguide layer comprises a plurality of waveguides which are arranged at intervals. The regulation and control parameters of the effective refractive index of the optical mode in the waveguide array along the light transmission direction meet the effective refractive index distribution function, the center-to-center distance parameters of two adjacent waveguides meet the center-to-center distance distribution function, and the optical wave front of the light is shaped after the light passes through at least one waveguide array. The on-chip optical wavefront shaping function is realized, and the on-chip optical wavefront shaping method has important application value for on-chip optical signal processing, especially for application scenes of high integration density and multiple optical channels, and can realize functions of on-chip optical field focusing, diffraction-free transmission, optical field regulation and control and the like.
Drawings
Fig. 1 is a schematic diagram of a waveguide array structure according to an embodiment of the present application.
Fig. 2 is a schematic cross-sectional view of the waveguide array structure of fig. 1 taken along line A-A.
Fig. 3 is a schematic structural view of another embodiment of the waveguide array structure 1 of the present application.
Fig. 4 is a schematic diagram of another embodiment of the waveguide array structure shown in fig. 3.
Fig. 5 is a schematic diagram illustrating another embodiment of the waveguide array structure shown in fig. 3.
Fig. 6 is a schematic diagram of another embodiment of a waveguide array structure of the present application.
FIG. 7 is a flow chart of one embodiment of a method for optical field modulation of a waveguide array structure of the present application.
FIG. 8 is a functional graph of one embodiment of a method of optical field manipulation for a waveguide array structure of the present application.
Fig. 9 is a schematic structural diagram of a waveguide array according to an embodiment of the present application formed by using an optical field modulation method of a waveguide array structure.
Fig. 10 is a schematic structural diagram of a waveguide array according to another embodiment of the present application formed by using the optical field modulation method of the waveguide array structure.
Fig. 11 is a schematic structural diagram of a waveguide array according to another embodiment of the present application formed by using an optical field modulation method of a waveguide array structure.
Detailed Description
Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the accompanying claims.
The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. "plurality" or "several" means at least two. Unless otherwise indicated, the terms "front," "rear," "lower," and/or "upper" and the like are merely for convenience of description and are not limited to one location or one spatial orientation. The word "comprising" or "comprises", and the like, means that elements or items appearing before "comprising" or "comprising" are encompassed by the element or item recited after "comprising" or "comprising" and equivalents thereof, and that other elements or items are not excluded. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.
As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.
The embodiment of the application provides a waveguide array structure and an optical field regulation and control method thereof. The waveguide array structure is used for shaping an on-chip optical wavefront and comprises at least one stage of waveguide array, wherein the waveguide array comprises a substrate layer, a buffer layer, a waveguide layer and a covering layer which are sequentially stacked from bottom to top, and the waveguide layer comprises a plurality of waveguides which are arranged at intervals; the regulation and control parameters of the effective refractive index of the optical mode in the waveguide array along the light transmission direction meet the effective refractive index distribution function, and the center-to-center distance parameters of two adjacent waveguides meet the center-to-center distance distribution function; the optical wavefront of the light is shaped after it passes through the at least one waveguide array.
The waveguide array structure and the optical field regulation and control method thereof are provided. The waveguide array structure is used for on-chip optical wavefront shaping. The waveguide array structure comprises at least one stage of waveguide array, the waveguide array comprises a substrate layer, a buffer layer, a waveguide layer and a covering layer which are sequentially stacked from bottom to top, and the waveguide layer comprises a plurality of waveguides which are arranged at intervals. The regulation and control parameters of the effective refractive index of the optical mode in the waveguide array along the light transmission direction meet the effective refractive index distribution function, the center-to-center distance parameters of two adjacent waveguides meet the center-to-center distance distribution function, and the optical wave front of the light is shaped after the light passes through at least one waveguide array. The on-chip optical wavefront shaping function is realized, and the on-chip optical wavefront shaping method has important application value for on-chip optical signal processing, especially for application scenes of high integration density and multiple optical channels, and can realize functions of on-chip optical field focusing, diffraction-free transmission, optical field regulation and control and the like.
Fig. 1 is a schematic diagram showing the structure of an embodiment of a waveguide array structure 1 of the present application. Fig. 2 is a schematic cross-sectional view of the waveguide array structure 1 of fig. 1 at line A-A. As shown in fig. 1 and 2, the waveguide array structure 1 is used for on-chip optical wavefront shaping. The waveguide array structure 1 comprises at least one stage of waveguide array 11. In the embodiment shown in fig. 1, the waveguide array 11 includes a waveguide array body 111 and an input connection region 112 provided at an input end of the waveguide array body 111 and an output connection region 113 provided at an output end of the waveguide array body 111. In the embodiment shown in fig. 2, the waveguide array 11 includes a substrate layer 114, a buffer layer 115, a waveguide layer 116, and a cover layer 117, which are sequentially stacked from bottom to top. In this embodiment, the waveguide array body 111 includes a substrate layer 114, a buffer layer 115, a waveguide layer 116, and a cover layer 117. Buffer layer 115 is located above substrate layer 114, waveguide layer 116 is located above buffer layer 115, and cladding layer 117 is located above waveguide layer 116. Waveguide layer 116 includes a plurality of spaced apart waveguides 118. The material of waveguide 118 includes, but is not limited to, silicon nitride, lithium niobate, group III-V, polymers, and the like. The effective refractive index of the optical mode in the waveguide array 11 along its optical transmission direction is regulated by a parameter that satisfies an effective refractive index distribution function, and the center-to-center distance of two adjacent waveguides 118 is parameter that satisfies a center-to-center distance distribution function. The optical wavefront of the light is shaped after it passes through the at least one waveguide array 11. The device realizes the on-chip optical wavefront shaping function, has important application value for on-chip optical signal processing, especially for application scenes of high integration density and multiple optical channels, and can realize the functions of on-chip optical field focusing, diffraction-free transmission, optical field regulation and the like.
In the embodiment shown in fig. 2, the tuning parameters include the materials of buffer layer 115, waveguide layer 116, and cladding layer 117; the width of waveguide 118; the thickness of waveguide layer 116; the etch depth of waveguide layer 116; the waveguide layer 116 transmits the wavelength of light; the polarization state of light field transmission by waveguide layer 116 and the mode of light field transmission by waveguide layer 116. In the embodiment shown in fig. 2, by configuring the materials of the buffer layer 115, the waveguide layer 116, and the cladding layer 117; the width L1 of the waveguide 118; the thickness H1 of the waveguide layer 116; the etch depth H2 of waveguide layer 116; the waveguide layer 116 transmits the wavelength of light; the polarization state of the optical field transmission of the waveguide layer 116 and the mode of the optical field transmission of the waveguide layer 116 are such that the effective refractive index distribution function is satisfied, thereby realizing the on-chip optical wavefront shaping function. In this embodiment, the effective refractive index distribution function includes a hyperbolic secant distribution function or a quadratic distribution function or other similar distribution functions, which are not limited in this application. In the embodiment shown in fig. 2, the on-chip optical wavefront shaping function is implemented by configuring the center-to-center spacing L2 of two adjacent waveguides 118 such that the center-to-center spacing distribution function is satisfied. In this embodiment, the center-to-center distance distribution function includes a hyperbolic secant distribution function or a quadratic distribution function or other similar distribution functions, which are not limited in this application.
Fig. 3 is a schematic structural view of another embodiment of the waveguide array structure 1 of the present application. As shown in fig. 3, the waveguide array structure 1 further includes an input waveguide 12 provided at an input end of the waveguide array 11 and an output waveguide 13 provided at an output end of the waveguide array 11. The input waveguide 12 is connected to an input connection region 112 of the waveguide array 11. The number of input waveguides 12 corresponds to the number of waveguide arrays 11. The length, width of each of the input waveguides 12 may be set to a specific value for adjusting the phase distribution of the optical field of the input waveguide 12. The output waveguide 13 is connected to an output connection region 113 of the waveguide array 11. The number of output waveguides 13 corresponds to the number of waveguide arrays 11. The input connection region 112 and the output connection region 113 realize connection of the input/output waveguide region to the waveguide array 11 by bending the waveguide and adiabatic the waveguide.
The optical wavefront is coupled into the waveguide array main body 111 through the input waveguide 12 at the input end of the waveguide array 11 and through the input connection region 112, and then is coupled out through the output waveguide 13 after passing through the waveguide array main body 111 and then through the input connection region 112 at the output end of the waveguide array 11, so as to realize the on-chip optical wavefront shaping function.
In the embodiment shown in fig. 3, the waveguide array structure 1 further comprises an optical modulator 14. An optical modulator 14 is provided in the input waveguide 12. The number of optical modulators 14 is set to at least one. The optical modulator 14 is used to achieve an adjustment of the intensity and/or phase and/or frequency of the optical field at the input of the waveguide array 11. In some embodiments, the optical modulator 14 includes at least one of a waveguide phase shifter, a Mach-Zehnder interferometer, a ring resonator. The waveguide phase shifter may adjust the phase of the optical field at the input of the waveguide array 11. The mach-zehnder interferometer may adjust the intensity of the optical field at the input of the waveguide array 11. The ring resonator may adjust the frequency of the optical field at the input of the waveguide array 11.
In the embodiment shown in fig. 3, the number of optical modulators 14 is set to one. The input waveguide 12 of the waveguide array structure 1 is provided with an optical modulator 14. In this embodiment, the input waveguide 12 of the waveguide array structure 1 may be provided with one of a waveguide phase shifter, a mach-zehnder interferometer, and a ring resonator. In this way, an adjustment of the intensity or phase or frequency of the optical field at the input of the waveguide array 11 can be achieved.
Fig. 4 is a schematic diagram showing a structure of a further embodiment of the waveguide array structure 1 shown in fig. 3. In the embodiment shown in fig. 4, the number of optical modulators 14 is two. The input waveguide 12 of the waveguide array structure 1 is provided with two optical modulators 14. In this embodiment, the input waveguide 12 of the waveguide array structure 1 may be provided with two of a waveguide phase shifter, a mach-zehnder interferometer, and a ring resonator. This allows adjustment of two of the intensity, phase, frequency of the optical field at the input of the waveguide array 11.
Fig. 5 is a schematic diagram showing the structure of another embodiment of the waveguide array structure 1 shown in fig. 3. In the embodiment shown in fig. 5, the number of optical modulators 14 is three. The input waveguide 12 of the waveguide array structure 1 is provided with three optical modulators 14. In the present embodiment, the input waveguide 12 of the waveguide array structure 1 may be provided with a waveguide phase shifter, a mach-zehnder interferometer, a ring resonator. In this way, the adjustment of the intensity, phase and frequency of the optical field at the input of the waveguide array 11 can be achieved.
In the embodiments shown in fig. 3-5, the optical modulator 14 may be configured as desired to obtain a desired output optical wavefront, for a wide range of applications.
Fig. 6 is a schematic structural view of a further embodiment of the waveguide array structure 1 of the present application. As shown in fig. 6, the waveguide array structure 1 includes a multistage waveguide array 11, in which the waveguide array 11 at the previous stage is cascade-connected with the waveguide array 11 at the subsequent stage through an output waveguide 13 connected to an output end thereof and an input waveguide 12 connected to an input end thereof in an optical transmission direction of the waveguide array 11. The optical wavefront of the light passing through the multi-stage waveguide array 11 is multi-stage shaped. In the embodiment shown in fig. 6, the waveguide array structure 1 includes a two-stage waveguide array 11, for example, including a first waveguide array 11a and a second waveguide array 11b, but is not limited thereto.
In the embodiment shown in fig. 6, the first waveguide array 11a includes a waveguide array body 111a and an input connection region 112a provided at an input end of the waveguide array body 111a and an output connection region 113a provided at an output end of the waveguide array body 111 a. The input connection region 112a of the waveguide array 11a is connected to the input waveguide 12a. The output connection region 113a of the waveguide array 11a is connected to the output waveguide 13a. The second waveguide array 11b includes a waveguide array body 111b, and an input connection region 112b provided at an input end of the waveguide array body 111b and an output connection region 113b provided at an output end of the waveguide array body 111 b. The input connection region 112b of the waveguide array 11b is connected to the input waveguide 12b. The output connection region 113b of the waveguide array 11b is connected to the output waveguide 13b. The second waveguide array 11b is located at a later stage of the first waveguide array 11 a. The input end of the second waveguide array 11b is connected to the output waveguide 13a of the first waveguide array 11a via the input waveguide 12b. The optical wavefront of the light passing through the two-stage waveguide array 11 is shaped in multiple stages. The optical wavefront is coupled into the waveguide array body 111a through the input waveguide 12a at the input end of the waveguide array 11a of the first waveguide array 11a, passes through the input connection region 112a at the output end of the waveguide array 11a after passing through the waveguide array body 111a, is coupled out through the output waveguide 13a, then passes through the input waveguide 12b at the input end of the waveguide array 11b of the second waveguide array 11b, is coupled into the waveguide array body 111b through the input connection region 112b, passes through the input connection region 112b at the output end of the waveguide array 11b after passing through the waveguide array body 111b, and is coupled out through the output waveguide 13b, thereby realizing the on-chip optical wavefront shaping function.
In the embodiment shown in fig. 6, the number of optical modulators 14 is set to at least one. In some embodiments, the number of optical modulators 14 may be set to one or more. In some embodiments, at least one optical modulator 14 is provided in the cascade-connected multi-stage waveguide array 11 with an input waveguide 12 connected to an input of the at least one waveguide array 11. The optical modulator 14 may be provided in the cascade-connected multi-stage waveguide array 11 with the input waveguide 12 connected to the input end of one or more waveguide arrays 11. And optical modulator 14 may be provided with one or more.
In the embodiment shown in fig. 6, the number of optical modulators 14 is set to one, and the optical modulator 14 may be one of a waveguide phase shifter, a mach-zehnder interferometer, and a ring resonator. The one optical modulator 14 may be provided at the input waveguide 12a of the input end of the waveguide array 11a of the first waveguide array 11a and/or at the input waveguide 12b of the input end of the waveguide array 11b of the second waveguide array 11b, so that an adjustment of the intensity or phase or frequency of the optical field at the input end of the waveguide array 11 may be achieved. The number of optical modulators 14 is scalable, and the two optical modulators 14 may be two of waveguide phase shifters, mach-zehnder interferometers, and ring resonators. The two optical modulators 14 may be arranged at the input waveguide 12a of the input end of the waveguide array 11a of the first waveguide array 11a and/or at the input waveguide 12b of the input end of the waveguide array 11b of the second waveguide array 11b, so that an adjustment of two of the intensity, phase, frequency of the optical field at the input end of the waveguide array 11 may be achieved. Similarly, the number of optical modulators 14 is three, and the three optical modulators 14 may be waveguide phase shifters, mach-Zehnder interferometers, ring resonators. The three optical modulators 14 may be disposed on the input waveguide 12a of the input end of the waveguide array 11a of the first waveguide array 11a and/or the input waveguide 12b of the input end of the waveguide array 11b of the second waveguide array 11b, so that the intensity, phase and frequency of the optical field of the input end of the waveguide array 11 may be adjusted. The waveguide phase shifter, the mach-zehnder interferometer, and the ring resonator may be disposed on the input waveguides 12 of the input ends of the different waveguide arrays 11, which are not described herein. By such arrangement, the number and position of the optical modulators 14 can be flexibly set according to actual requirements, so as to adjust the intensity, phase and frequency of the optical field at the input end of the waveguide array 11.
Fig. 7 is a flowchart of an embodiment of an optical field modulation method of the waveguide array structure 1 of the present application. The optical field regulation method of the waveguide array structure 1 is applied to the waveguide array structure 1 shown in the embodiments of fig. 1 to 7, and on-chip optical wavefront shaping is realized based on the discrete diffraction property regulation of the dielectric waveguide array 11. As shown in fig. 7, the optical field adjusting method of the waveguide array structure 1 includes steps S1 to S4.
Step S1, setting regulation parameters of effective refractive indexes of optical modes in the waveguide array 11 along the light transmission direction of the optical modes, so that the effective refractive indexes meet an effective refractive index distribution function. In this embodiment, the effective refractive index distribution function includes a hyperbolic secant distribution function or a quadratic distribution function or the like.
And S2, setting center-to-center distance parameters of two adjacent waveguides to enable the center-to-center distance parameters to meet a center-to-center distance distribution function. In this embodiment, the inter-center distance distribution function includes a hyperbolic secant distribution function or a quadratic distribution function.
And S3, determining the diffraction coefficient of the waveguide array 11 along the light transmission direction according to the regulation and control parameters of the effective refractive index and the center-to-center distance parameters of the adjacent two waveguides. In this embodiment, by selecting a suitable effective refractive index regulation parameter and a suitable center-to-center distance parameter between two adjacent waveguides, and combining an adaptive distribution function, the expression form of the diffraction coefficient can be obtained.
And S4, regulating and controlling the optical field of the optical mode in the waveguide array 11 along the light transmission direction according to the diffraction coefficient. In this embodiment, after determining the diffraction coefficient, the method may be used to implement the adjustment and control of the light transmission direction wave vector of the light field in the waveguide array 11.
In the embodiment shown in fig. 7, the optical field modulation method of the waveguide array structure 1 implements on-chip optical wavefront shaping based on discrete diffractive property modulation of the dielectric waveguide array 11. Specifically, the designed regulation parameters of the effective refractive index of the parameters and the center-to-center distance parameters of two adjacent waveguides are required. Under the combined action of the effective refractive index regulation parameter and the central distance parameter of two adjacent waveguides, specific corresponding discrete diffraction characteristics are realized inside the waveguide array 11.
In the present embodiment, based on the coupling mode equation of the basic waveguide array 11, it is expressed by expression (1):
；（1）
wherein,
is the +.>An electric field of the root waveguide;
is a transmission wave vector in the waveguide;
is the coupling coefficient of adjacent waveguides.
Wave vector of waveguide array 11 along its transmission directionAnd->Is represented by expression (2):
；（2）
wherein,
a wave vector function for the light transmission direction of the waveguide array 11, which varies along the transmission direction;
As a function of the waveguide spacing of the waveguide array 11 as it varies along its propagation direction.
Further, the diffraction coefficient of the discrete waveguide array 11 can be obtained, expressed by expression (3):
；（3）
wherein,
；
；
and->Are a function of the variation of the waveguide array 11 along its propagation direction;
as a function of the effective refractive index of the waveguide mode along the direction of propagation of the waveguide array 11;
and->、/>And->Fitting parameters for a hyperbolic secant function.
In this embodiment, the optical field adjusting method of the waveguide array structure 1 is used to determine the diffraction coefficient of the discrete waveguide array 11. Wherein (1)>And->And meanwhile, the hyperbolic secant function distribution is satisfied.
In the embodiment shown in fig. 1-7, waveguide array 11 includes a plurality of waveguides 118 having a width distributionSetting according to the function requirement. The size of the light field transmission wave vector in each waveguide 118 in the waveguide array 11 can be adjusted by changing the thickness H1 of the waveguide layer 116 and the etching depth H2 of the waveguide layer 116, and the alignment of +_ can be assisted>Is provided. The center-to-center spacing L2 of the two waveguides 118 can be used to achieve p +>And->Adjustment of the distribution form. By selecting the proper thickness H1 of the waveguide layer 116, the etching depth H2 of the waveguide layer 116 and the center-to-center distance L2 of the two waveguides 118, the proper +. >And->Distribution, desired diffraction coefficient +.>In the form of an expression of (a).
In this embodiment, the adjustment parameters of the effective refractive index and the center-to-center distance parameters of two adjacent waveguides are both adapted to fit parameters of a suitable hyperbolic secant function, so as to obtain the expected discrete diffraction coefficient of the waveguide array 11Is a distribution of (a). So arranged, the discrete diffraction has abnormal diffraction phenomenon which is not existed in continuous space and can be used forThe regulation and control of the light field wave vector in the light transmission direction are realized.
In the embodiment shown in fig. 7, in step S3, when it is determined that the diffraction coefficient is positive and/or negative in the light transmission direction of the waveguide array 11, the transmission form of the incident optical wavefront in the waveguide array 11 is diffraction. In the embodiment shown in fig. 7, when it is determined that the diffraction coefficient is positive in the light transmission direction of the waveguide array 11, the transmission form of the incident optical wavefront in the waveguide array 11 is anomalous diffraction. When the selected regulation parameter of the effective refractive index and the central distance parameter of two adjacent waveguides enable the light field of the diffraction coefficient along the light transmission direction to be positive value all the time, the transmission process of the incident optical wavefront in the waveguide array 11 is represented as diffraction.
In the embodiment shown in fig. 7, when it is determined that the diffraction coefficient is negative in the light transmission direction of the waveguide array 11 in step S3, the transmission form of the incident optical wavefront in the waveguide array 11 is normal diffraction. When the selected regulation parameters of the effective refractive index and the central distance parameters of two adjacent waveguides enable the light field of the diffraction coefficient along the light transmission direction to be always negative, the transmission process of the incident optical wavefront in the waveguide array 11 is expressed as normal diffraction.
In the embodiment shown in fig. 7, in step S3, when it is determined that the diffraction coefficient is zero in the light transmission direction of the waveguide array 11, the incident optical wavefront is not diffracted in the waveguide array 11. When the selected regulation and control parameters of the effective refractive index and the central distance parameters of two adjacent waveguides enable the optical field of the diffraction coefficient along the optical transmission direction to be zero, the transmission process of the incident optical wavefront in the waveguide array 11 is expressed as diffraction-free transmission.
Fig. 8 is a functional diagram showing an embodiment of the optical field modulation method of the waveguide array structure 1 of the present application. FIG. 8 shows the diffraction coefficients of waveguide array 11Is a typical distribution of the same. In the embodiment shown in fig. 8, the abscissa is its light transmission direction position, that is, the position of the waveguide array 11 along its light transmission direction; ordinate is. Due to the introduction of the gradient waveguide width distribution, the diffraction coefficient +.>Both positive and negative values may be present in the distribution along its light transmission direction. When the diffraction coefficient->When the sign of (2) is negative, the diffraction coefficient corresponds to the normal diffraction process>And the sign of (c) is positive, corresponding to an anomalous diffraction process. Due to->Coupling coefficient->Andall positive values, diffraction coefficient->The sign at is by- >And (3) uniquely determining. When (when)When the diffraction is positive, the diffraction process is normal; when->When the diffraction is negative, the diffraction process is abnormal; when->Zero corresponds to no diffraction process. Different types of diffraction processes correspond to different wave vector movements in the light transmission direction, and different shaping effects on the input optical wave front can be achieved.
FIG. 9 showsA schematic structure diagram of a waveguide array 11 according to an embodiment of the present application formed by using the optical field modulation method of the waveguide array structure 1 is shown. In the embodiments shown in fig. 7 and 9, the diffraction coefficient of the region through which the light field is transmittedThe sign of (a) is only negative (or only positive), i.e. there is only a normal diffraction process (or an anomalous diffraction process). Since there is only a single type of diffraction process, the transmission of the optical field appears to diverge when light is input to the central waveguide in this waveguide array 11.
Fig. 10 is a schematic diagram of a waveguide array 11 according to another embodiment of the present application formed by using the optical field modulation method of the waveguide array structure 1. In the embodiments shown in fig. 7 and 10, the diffraction coefficient of the region through which the light field is transmittedThe sign of (c) is zero, corresponding to a non-diffracting process. When light is input in this region, the transmission of the light field appears as diffraction-free transmission.
In the embodiment shown in fig. 7, in step S3, when it is determined that the diffraction coefficient has a positive value and a negative value in the light transmission direction of the waveguide array 11, and the integral of the diffraction coefficient in the light transmission direction of the waveguide array 11 is zero, the transmission form of the incident optical wavefront in the waveguide array 11 is self-focusing. When the selected regulation parameters of the effective refractive index and the center-to-center distance parameters of two adjacent waveguides enable the light field of the diffraction coefficient along the light transmission direction to simultaneously generate positive values and negative values, and the integral of the light field of the diffraction coefficient along the light transmission direction is close to 0, the transmission process of the incident optical wavefront in the waveguide array 11 is shown to be self-focusing.
In the embodiment shown in fig. 7, in step S3, when it is determined that the diffraction coefficient has a positive value and a negative value in the light transmission direction of the waveguide array 11, the integral of the diffraction coefficient in the light transmission direction of the waveguide array 11 is zero, and the effective refractive index of the optical mode in the waveguide array 11 satisfies the effective refractive index distribution function, the transmission form of the incident optical wavefront in the waveguide array 11 is the transmission form through the lens. When the selected regulation and control parameters of the effective refractive index and the center-to-center distance parameters of two adjacent waveguides enable the light field of the diffraction coefficient along the light transmission direction to simultaneously generate positive values and negative values, the integral of the light field of the diffraction coefficient along the light transmission direction is close to zero, and meanwhile, the mode effective refractive index distribution in the waveguide array 11 meets the approximate quadratic function distribution, the waveguide array 11 can be approximately equivalent to a lens, and the operation and control of the incident optical wave front can be realized.
Fig. 11 is a schematic structural diagram of a waveguide array 11 according to another embodiment of the present application formed by using the optical field modulation method of the waveguide array structure 1. In the embodiments shown in fig. 7 and 11, the diffraction coefficient of the region through which the light field is transmittedThe sign of (2) has both negative and positive values in different regions along its light transmission direction and the diffraction coefficient +.>The integral along its light transmission direction is approximately equal to zero. In the waveguide array 11, after light is inputted from a certain waveguide, the transmission of the optical field first appears divergent, and the diffraction coefficient at that time is +.>The value is negative (or positive) when the optical field diverges into the waveguide array 11 by the diffraction coefficient +.>After the positive (or negative) area, diffraction of the light transmission direction is counteracted, the light field is gradually focused, and after a certain transmission distance, the light field energy is completely focused into the initial input waveguide 12, namely, a self-imaging phenomenon. In particular, if the distribution of the effective refractive index of the waveguide mode in the waveguide array 11 of this type along the light transmission direction thereof satisfies the approximate quadratic function distribution, the modulation of the optical field by the waveguide array 11 of this type can be equivalent to a paraxial fourier lens.
For the case where the waveguide array 11 is equivalent to a lens, the effective refractive index of the mode of the optical field transmitted in the waveguide array 11 is made to satisfy by selecting appropriate waveguide array 11 parameters:
；
The effective refractive index of the mode has equivalent mathematical form with that of the space Fourier lens, and can realize the phase modulation function of the optical wavefront. Thus, the transmission manipulation of the optical field can be achieved by varying the phase distribution of the incident optical wavefront.
The waveguide array structure 1 shown in fig. 1 to 6 is formed based on the optical field regulation method of the waveguide array structure 1. The present embodiment provides two methods of changing the phase distribution of an incident optical wavefront, by a passive optical modulator 14 (optical phase shifter) and an active optical modulator 14 (optical phase shifter), respectively. The passive optical modulator 14 (optical phase shifter) modulates the phase by changing the length or width of the incident end waveguide, and the active optical modulator 14 (optical phase shifter) modulates the phase of the incident end waveguide by an electro-optic effect or a thermo-optic effect from an external electrode. When an incident optical wavefront passes through this type of waveguide array 11, the transmission behavior is equivalent to the optical wavefront passing through a fourier lens in space. When a plurality of waveguide arrays 11 of this type are cascaded, their function is equivalent to a lens group in space.
Referring back to fig. 3, in the embodiment, the optical field adjusting method based on the waveguide array structure 1 has the diffraction coefficient of the waveguide array 11 Has both negative and positive values in different regions along its light transmission direction, and diffraction coefficientThe integral along its light transmission direction is approximately equal to zero. Meanwhile, the distribution of the effective refractive index of the waveguide mode in the waveguide array 11 along the light transmission direction thereof satisfies the approximate quadratic function distribution, so that the regulation and control of the waveguide array 11 on the light field can be equivalent to a paraxial Fourier lens. The intensity and phase distribution of the incident light is distributed by the input waveThe guiding region is arranged such that as the light field propagates through the waveguide array 11, the light field distribution is equivalent to passing through a fourier lens, the waveguide array 11 phase-modulates and images the input light field. The optical field distribution after lens modulation can be obtained through the output of the output waveguide.
In some embodiments, optical modulator 14 is provided as an active phase shifter. The phase distribution of the incident light is controlled in real time by the active phase shifter, and as the light field is transmitted through the waveguide array 11, the light field distribution is equivalent to passing through a fourier lens, and the waveguide array 11 performs phase modulation and imaging on the input light field. The optical field distribution after lens modulation can be obtained through the output of the output waveguide. According to the actually required optical wavefront, the phase adjustment distribution of the corresponding active phase shifter can be set, and the real-time incident optical wavefront phase adjustment is carried out by combining the feedback signal of the output optical field, so that the required output optical wavefront is obtained.
In other embodiments, the optical modulator 14 is configured as a Mach-Zehnder interferometer. The optical field incident on the waveguide array 11 is modulated by the mach-zehnder interferometer in the input region, and its intensity distribution can be modulated on-chip in real time. When the light field is transmitted through the waveguide array 11, the light field distribution is equivalent to passing through a fourier lens, and the waveguide array 11 intensity modulates and images the input light field. The light field is output through the waveguide of the output area, and the light field distribution after lens modulation can be obtained. According to the actually required optical wavefront, the output intensity distribution of the corresponding Mach-Zehnder interferometer can be set, and the real-time incident optical wavefront intensity adjustment is carried out by combining the feedback signal of the output light field, so that the required output optical wavefront is obtained.
Referring back to the embodiment shown in fig. 4, the optical modulator 14 is configured as an active phase shifter and a mach-zehnder interferometer. The intensity of the incident optical field is adjusted by the mach-zehnder interferometer of the input region, which is then phase-adjusted by the active phase shifter. The waveguide array structure 1 intensity modulates, phase modulates and images the input light field as it passes through the waveguide array 11, the light field distribution being equivalent to passing through a fourier lens. According to the actually required optical wave front, corresponding Mach-Zehnder interferometer output intensity distribution and active phase shifter phase adjustment distribution can be set, and the real-time incident optical wave front phase adjustment is carried out by combining the feedback signal of the output light field, so that the required output optical wave front is obtained.
Referring back to the embodiment shown in fig. 6, the waveguide array structure 1 comprises a multi-level waveguide array 11 with diffraction coefficientsThe sign of (2) has both negative and positive values in different regions along its light transmission direction and the diffraction coefficient +.>The integral along its light transmission direction is approximately equal to zero. Meanwhile, the distribution of the effective refractive index of the waveguide mode of each waveguide array 11 in the waveguide array structure 1 along the light transmission direction thereof satisfies the approximate quadratic function distribution, so that the modulation and control of the waveguide array structure 1 to the light field can be equivalent to a fourier lens group including a plurality of lenses.
In some embodiments, optical modulator 14 is provided as an active phase shifter. The phase distribution of the incident light is controlled in real time by the active phase shifters, as the light field passes through each waveguide array 11, the light field distribution is equivalent to passing through one fourier lens, and as the light field passes through the entire waveguide array structure 1, is equivalent to passing through one fourier lens group. The set of waveguide arrays 11 phase modulates and images the input optical field. The optical field distribution after lens modulation can be obtained through the output of the output waveguide. According to the actually required optical wavefront, the phase adjustment distribution of the active phase shifter in front of each layer of waveguide array 11 in the structure can be set, and the real-time incident optical wavefront phase adjustment is performed by combining the feedback signal of the output light field, so as to obtain the required output optical wavefront.
In other embodiments, the optical modulator 14 is configured as a Mach-Zehnder interferometer. The intensity distribution of the incident light is controlled in real time by means of a mach-zehnder interferometer, the light field distribution being equivalent to passing through one fourier lens when the light field is transmitted through each waveguide array 11, and equivalent to passing through one fourier lens group when the light field is transmitted through the entire waveguide array structure 1. The set of waveguide arrays 11 phase modulate and image the input optical field. The optical field distribution after lens modulation can be obtained through the output of the output waveguide. According to the actually required optical wavefront, the output intensity distribution of the Mach-Zehnder interferometer in front of each layer of waveguide array 11 in the structure can be set, and the real-time incident optical wavefront intensity adjustment can be performed by combining the feedback signal of the output light field, so as to obtain the required output optical wavefront.
The optical modulator 14 is arranged as an active phase shifter and a mach-zehnder interferometer. The intensity distribution of the incident light is controlled in real time by a Mach-Zehnder interferometer, the phase distribution is controlled in real time by an active phase shifter, each layer of waveguide array 11 can carry out independent intensity and phase modulation once, after the light field is output from the output area, the intensity and phase adjustment of the incident optical wave front in the waveguide array 11 group is carried out by combining the feedback signal of the output light field, and the required output optical wave front is obtained.
The optical field regulation and control method of the waveguide array structure 1 can guide the wave front shaping design of the waveguide array structure 1 in different material platforms, and can realize the functions of on-chip optical field focusing, diffraction-free transmission, optical field regulation and control and the like through the parameter design of the waveguide array structure 1. And can realize high-density and expandable on-chip optical signal processing and interconnection, and can realize artificial regulation and control of optical wave front in a waveguide system. The waveguide array 11 is an important structure in a waveguide system, and is composed of a plurality of waveguides arranged according to a predetermined rule. The waveguide array 11 has high integration density, and is one of important structural systems for large-scale photon integration. The present embodiment realizes the on-chip optical wavefront shaping function in the waveguide array 11, and has important application value for on-chip optical signal processing, especially for application scenarios of high integration density and multiple optical channels.
The foregoing description of the preferred embodiments of the present invention is not intended to limit the invention to the precise form disclosed, and any modifications, equivalents, improvements and alternatives falling within the spirit and principles of the present invention are intended to be included within the scope of the present invention.
Claims (12)
1. The waveguide array structure is characterized by comprising at least one stage of waveguide array, wherein the waveguide array comprises a substrate layer, a buffer layer, a waveguide layer and a covering layer which are sequentially laminated from bottom to top, and the waveguide layer comprises a plurality of waveguides which are arranged at intervals; the regulation and control parameters of the effective refractive index of the optical mode in the waveguide array along the light transmission direction meet the effective refractive index distribution function, and the center-to-center distance parameters of two adjacent waveguides meet the center-to-center distance distribution function; the optical wavefront of the light passing through at least one of said arrays of waveguides is shaped;
And determining a diffraction coefficient of the waveguide array along the light transmission direction according to the regulation and control parameters of the effective refractive index and the center-to-center distance parameters of two adjacent waveguides, wherein when the diffraction coefficient is determined to be positive and/or negative along the light transmission direction of the waveguide array, the integral of the diffraction coefficient along the light transmission direction of the waveguide array is zero, and when the effective refractive index of an optical mode in the waveguide array meets the effective refractive index distribution function, the transmission form of an incident optical wavefront in the waveguide array is the transmission form of a lens.
2. The waveguide array structure according to claim 1, wherein the tuning parameters include materials of the buffer layer, the waveguide layer, and the cover layer; the width of the waveguide; the thickness of the waveguide layer; the etching depth of the waveguide layer; the waveguide layer transmits the wavelength of light; the polarization state of the optical field transmission of the waveguide layer and the mode of the optical field transmission of the waveguide layer; and/or
The effective refractive index distribution function comprises a hyperbolic secant distribution function or a quadratic distribution function; and/or
The inter-center distance distribution function comprises a hyperbolic secant distribution function or a quadratic distribution function.
3. The waveguide array structure of claim 1, further comprising an optical modulator; the waveguide array structure further comprises an input waveguide arranged at the input end of the waveguide array and an output waveguide arranged at the output end of the waveguide array, and the optical modulator is arranged at the input waveguide.
4. The waveguide array structure according to claim 3, wherein the optical modulator comprises at least one of a waveguide phase shifter, a mach-zehnder interferometer, and a ring resonator.
5. The waveguide array structure according to claim 4, wherein the number of the optical modulators is set to at least one;
the number of the optical modulators is one, and the input waveguide of the waveguide array structure is provided with one of the waveguide phase shifter, the Mach-Zehnder interferometer and the ring resonator; or (b)
The number of the optical modulators is two, and the input waveguide of the waveguide array structure is provided with two of the waveguide phase shifter, the Mach-Zehnder interferometer and the ring resonator; or (b)
The number of the optical modulators is three, and the input waveguide of the waveguide array structure is provided with the waveguide phase shifter, the Mach-Zehnder interferometer and the ring resonator.
6. The waveguide array structure according to claim 3 or 4, characterized in that the waveguide array structure comprises a multistage waveguide array in which the waveguide array at a preceding stage is cascade-connected with the waveguide array at a subsequent stage through the output waveguide connected to its output terminal and the input waveguide connected to its input terminal in the light transmission direction of the waveguide array; the optical wavefront of the light passing through the multi-stage waveguide array is shaped in multiple stages.
7. The waveguide array structure according to claim 6, wherein the number of the optical modulators is set to at least one; at least one of the optical modulators is disposed in the cascade-connected multistage waveguide array in the input waveguide connected to the input end of at least one of the waveguide arrays.
8. The optical field regulation and control method of the waveguide array structure is characterized in that the waveguide array structure is used for on-chip optical wavefront shaping; the waveguide array structure comprises a waveguide array, wherein the waveguide array comprises a plurality of waveguides; the optical field regulation and control method of the waveguide array structure comprises the following steps:
setting a regulation parameter of an effective refractive index of an optical mode in the waveguide array along the light transmission direction of the optical mode, so that the effective refractive index meets an effective refractive index distribution function;
Setting center-to-center distance parameters of two adjacent waveguides to enable the center-to-center distance parameters to meet a center-to-center distance distribution function;
determining a diffraction coefficient of the waveguide array along the light transmission direction according to the regulation and control parameters of the effective refractive index and the center-to-center distance parameters of two adjacent waveguides; and
According to the diffraction coefficient, regulating and controlling the optical field of an optical mode in the waveguide array along the light transmission direction of the optical mode;
wherein determining the diffraction coefficient of the waveguide array along the light transmission direction according to the regulation parameter of the effective refractive index and the center-to-center distance parameter of two adjacent waveguides comprises:
when the diffraction coefficient is determined to be positive and/or negative along the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is diffraction;
wherein when the diffraction coefficient is determined to be positive and/or negative along the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is diffraction, including:
when it is determined that the diffraction coefficient has positive and negative values along the light transmission direction of the waveguide array, the integral of the diffraction coefficient along the light transmission direction of the waveguide array is zero, and the effective refractive index of the optical mode in the waveguide array satisfies the effective refractive index distribution function, the transmission form of the incident optical wavefront in the waveguide array is a transmission form through a lens.
9. The light field manipulation method of claim 8 wherein an incident optical wavefront is not diffracted in said waveguide array when said diffraction coefficient is determined to be zero along a light transmission direction of said waveguide array.
10. The method according to claim 9, wherein when determining that the diffraction coefficient is positive and/or negative in the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is diffraction, comprising:
when the diffraction coefficient is determined to be positive in the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is abnormal diffraction; or (b)
When the diffraction coefficient is determined to be negative in the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is normal diffraction.
11. The method according to claim 9, wherein when determining that the diffraction coefficient is positive and/or negative in the light transmission direction of the waveguide array, the transmission form of the incident optical wavefront in the waveguide array is diffraction, comprising:
when it is determined that the diffraction coefficient has positive and negative values along the light transmission direction of the waveguide array, and the integral of the diffraction coefficient along the light transmission direction of the waveguide array is zero, the transmission form of the incident optical wavefront in the waveguide array is self-focusing.
12. The light field modulation method according to claim 8, wherein the waveguide array comprises a substrate layer, a buffer layer, a waveguide layer and a cover layer which are sequentially stacked from bottom to top, and the waveguide layer comprises a plurality of waveguides which are arranged at intervals; the regulation parameters comprise materials of the buffer layer, the waveguide layer and the cover layer; the width of the waveguide; the thickness of the waveguide layer; the etching depth of the waveguide layer; the waveguide layer transmits the wavelength of light; the polarization state of the optical field transmission of the waveguide layer and the mode of the optical field transmission of the waveguide layer; and/or
The effective refractive index distribution function comprises a hyperbolic secant distribution function or a quadratic distribution function; and/or
The inter-center distance distribution function comprises a hyperbolic secant distribution function or a quadratic distribution function.
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