Sories photon pump array based on two-dimensional non-Abeth and Leg principle and pumping method thereof

Abstract

The invention discloses a Sories photon pump array based on the two-dimensional non-Abeth and Lo principle and a pumping method of the Sories photon pump array, and belongs to the technical field of laser micro-nano machining, and the Sories photon pump array is formed by stacking a plurality of waveguide unit cells in a close arrangement mode in the vertical propagation direction; wherein the plurality of waveguide unit cells are of a'basket 'structure; the waveguide unit cell comprises a first main waveguide, a second main waveguide, a first auxiliary waveguide, a second auxiliary waveguide, a first straight waveguide and a second straight waveguide; the first main waveguide is located on the bottom face of the vegetable basket structure, the second main waveguide and the first auxiliary waveguide are located on the two side faces of the vegetable basket structure respectively, the second auxiliary waveguide is located on the handle face, symmetrical to the bottom face, of the vegetable basket structure, and the first straight waveguide and the second straight waveguide are located on two parallel side lines of the bottom face of the vegetable basket structure respectively. The direction is the propagation direction. The mode of periodically adjusting the coupling coefficient between the waveguides in the transverse direction and the longitudinal direction is used for conducting three-dimensional integration on the Solis photon pump in the horizontal direction and the vertical direction, and therefore photon control can be conducted in the transverse direction and the longitudinal direction at the same time. According to the invention, the calculation dimension of the Sories photon pump device is further improved, and one-step construction and preparation of the high-order unitary matrix operation module based on the Sories pump are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of laser micro-nano processing, and specifically relates to a Thouless photon pump array based on a two-dimensional non-Abelian principle and a pumping method thereof. Background Art

[0002] With the development of topological photonics in recent years, the control of photon states in a topologically protected manner has received increasing attention. The Thouless photon pump based on the non-Abelian principle has the characteristics of high robustness and global anti-interference, and is one of the ideal photonic devices for realizing non-Abelian optical computing. Compared with the method of preparing the Thouless photon pump using planar processes such as masks, the femtosecond laser direct writing technology can focus high-energy laser pulses into the transparent material through an objective lens, and nonlinear absorption occurs in the focal area, which increases the refractive index of the material, thereby realizing the preparation of arbitrary three-dimensional waveguides. This preparation method has the advantages of true three-dimensional processing, fast tape-out speed, and low preparation cost. However, how to use the large depth processing capability of femtosecond lasers to prepare large-scale three-dimensional Thouless photon pump arrays is the main challenge at present.

[0003] At present, the research groups of various countries have implemented the Thouless photon pump based on the one-dimensional non-Abelian and Le principle in materials such as glass and silicon nitride. Photon manipulation can only be performed in a single pump or a single horizontal direction. Although the waveguide has three-dimensional rotation and other directions in this process, the total depth does not exceed the order of ten microns, and it is impossible to give full play to the advantages of large-depth direct writing of femtosecond lasers. More importantly, the above structure has the problem of insufficient computing dimensions and difficulty in realizing high-order unitary matrix operation modules of photon states, which seriously restricts the scale and complexity of on-chip topological optical computing.

[0004] Therefore, there is an urgent need for a method that can achieve arbitrary directional photon state pumping over a large depth range, so as to further enhance the application capability of the Thouless photon pump in topological optical computing. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a Solis photon pump array based on a two-dimensional non-Abelian and Le principle and a pumping method thereof. Different from the existing Solis photon pump based on a one-dimensional non-Abelian and Le principle, this method utilizes the method of periodically adjusting the coupling coefficients in the horizontal and vertical directions between waveguides to integrate the Solis photon pump in the horizontal and vertical directions, thereby allowing photon manipulation to be performed in both the horizontal and vertical directions at the same time. The present invention further improves the computational dimension of the Solis photon pump device, and realizes the one-step construction and preparation of a high-order unitary matrix operation module based on the Solis pump.

[0006] The principle of the present invention is as follows:

[0007] The Solis photon pump is a pumping structure formed by periodic changes in the Hamiltonian parameter space of the waveguide array. According to the non-Abelian and Le principle, when a pair of coupling coefficients between the three-waveguide system presents symmetrical increases and decreases, the photon state can be pumped from the starting waveguide to the ending waveguide in a highly robust manner protected by the topological properties of the Hilbert space. To design a Solis photon pump based on the two-dimensional non-Abelian and Le principle, first consider the required light evolution direction, calculate the pumping direction and path of the Solis pump, that is, the curve equation of the waveguide during the processing. Focus a high-energy pulse laser that reaches a specific energy threshold inside the transparent material, and then use a high-precision motion control platform to make the sample move continuously in three dimensions relative to the focus position, so that the focus writes a continuous modified area inside the material, thereby realizing the preparation of a Solis photon pump array arranged in parallel in three dimensions. Six waveguides described by designed curve equations form a three-dimensional waveguide unit cell. The cells are stacked according to the required three-dimensional device scale and connected by a Solis pump. Since the coupling coefficient shows periodic changes, when the incident light is input from any degenerate waveguide in the incident surface, the same high-robustness path transmission can be achieved and broadband characteristics can be exhibited.

[0008] The present invention is achieved through the following technical solutions:

[0009] A Solis photon pump array based on a two-dimensional non-Abelian and Le principle, wherein the Solis photon pump array is formed by stacking a plurality of waveguide unit cells in a densely packed manner in a vertical propagation direction; wherein the plurality of waveguide unit cells are all "vegetable basket" structures; the waveguide unit cells include a first main waveguide 1, a second main waveguide 2, a first auxiliary waveguide 3, a second auxiliary waveguide 4, a first straight waveguide 5 and a second straight waveguide 6; the first main waveguide 1 is located on the bottom surface of the "vegetable basket" structure, the second main waveguide 2 and the first auxiliary waveguide 3 are respectively located on two side surfaces of the "vegetable basket" structure, the second auxiliary waveguide 4 is located on a handle surface of the "vegetable basket" structure that is symmetrical to the bottom surface, and the first straight waveguide 5 and the second straight waveguide 6 are respectively located on two mutually parallel side lines of the bottom surface of the "vegetable basket" structure, and their directions are the propagation direction.

[0010] Furthermore, the first main waveguide 1 in the plurality of waveguide unit cells constitutes a first rhombus grid that changes periodically along the oblique direction, and the second main waveguide 2 in the plurality of waveguide unit cells constitutes a second rhombus grid that changes periodically along the oblique direction. When observed along one of the 45-degree oblique lines, the main waveguide 1 layer and the main waveguide 2 layer appear alternately and the waveguides are collinear. The oblique line is defined as the change direction of the cell position number i, and another oblique line perpendicular to it is defined as the change direction of the position number j. Any point in the first rhombus grid is marked as A. ij , any point in the second diamond grid is marked as B ij ; When the test light is from any point A in the first diamond grid ijWhen input, it is transmitted to any point B in the second diamond grid through a finite number of couplings ij Output; conversely, the test light can also be output from any point B in the second diamond grid ij Transmit to any point A in the first diamond grid ij ; Among them, i and j are cell position numbers.

[0011] Furthermore, the lattice spacing of the first diamond grid and the second diamond grid is in the range of 40-160λ, and the interlaced layer spacing of the first diamond grid and the second diamond grid is in the range of 20-80λ; the spacing d between the first straight waveguide 5 and the second straight waveguide 6 is 0 The range is 30-120λ, where λ is the wavelength of the test excitation light of the pump.

[0012] Furthermore, the first main waveguide 1, the second main waveguide 2, the first auxiliary waveguide 3, and the second auxiliary waveguide 4 evolve in a straight line or a curve in their respective planes, and during the evolution process, the spatial distance between the first main waveguide 1, the second main waveguide 2, the first auxiliary waveguide 3, and the second auxiliary waveguide 4 and the first straight waveguide 5 and the second straight waveguide 6 at the edge of the plane is the coupling spacing, wherein the maximum coupling spacing d 1 The selection range is 15-115λ, and the minimum coupling spacing d 2 The selection range is 5-15λ, and d 1 >d 2 Since the first straight waveguide 5 is parallel to the second straight waveguide 6, there exists a relationship d 1 +d 2 =d 0 .

[0013] Furthermore, the overall size of the waveguide unit cell is d 0 ×d 0 × tp , where l tp is the propagation length of the one-step Solis pump, ranging from 10 4 -10 5 λ; the unit cells are stacked in a two-dimensional plane in the vertical propagation direction and directly connected in the propagation direction, and the number of lateral periods of the cells of the composed device is n x , the number of longitudinal periods is n y , the number of pumping steps in the propagation direction is n tp , then the overall size of the device is n x d 0 ×n y d 0 ×n tp l tp .

[0014] On the other hand, the present invention provides a pumping method of a Thouless photon pump array based on a two-dimensional non-Abelian principle, which specifically includes the following contents:

[0015] When the test light is input from the first main waveguide 1 of the waveguide unit cell, it will be pumped to the second main waveguide 2 of the same waveguide unit cell via the first straight waveguide 5; when the test light is input from the second main waveguide 2 of the waveguide unit cell, it will be pumped to the first auxiliary waveguide 3 of the lower right corner cell in turn, and then pumped to the first main waveguide 1 of the cell, thereby realizing energy exchange between the first main waveguide 1 and the second main waveguide 2.

[0016] Compared with the prior art, the advantages of the present invention are as follows:

[0017] (1) Compared with the Thouless pump prepared based on the one-dimensional non-Abelian and Le principle, the present invention can prepare photon state pumping in both horizontal and vertical directions inside the transparent material, and can be expanded to any size according to the device requirements; more importantly, since the increase in the pumping dimension brings about the increase in the computing dimension, the present invention can provide a highly robust solution for more complex on-chip optical computing;

[0018] (2) The present invention introduces the two-dimensional non-Abelian and Le principle into the Solis photon pump array in a unitized and standardized manner, and simply and intuitively demonstrates the description and connection method of the waveguide unit cell, which has the advantage of being able to be arbitrarily connected and integrated with other three-dimensional photonic devices;

[0019] (3) The Thouless photon pump array based on the two-dimensional non-Abelian and Le principle described in the present invention has a topologically protected pumping method and a global non-resonant effect. Therefore, it has the significant advantages of large working bandwidth and immunity to local interference, and can provide a new and valuable solution for large-bandwidth, high-robustness on-chip optical computing devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0021] Figure 1 It is a schematic diagram of the overall structure of the Solis photon array based on the two-dimensional non-Abelian harmony principle of the present invention;

[0022] (a) is a schematic diagram of the three-dimensional structure of the unit cell of the three-step pumping Solis photon pump array device; (b) is a schematic diagram of the cross section of the unit cell;

[0023] Among them, a first main waveguide 1, a second main waveguide 2, a first auxiliary waveguide 3, a second auxiliary waveguide 4, a first straight waveguide 5, and a second straight waveguide 6;

[0024] Figure 2 A schematic diagram of a processing device for preparing a two-dimensional non-Abelian and Le principle-based Solis photon pump array by femtosecond laser direct writing according to the present invention;

[0025] Among them, HWP-half wave plate, GTL-Glan-Taylor prism, L 1 -First concave lens, L 2 - Second convex lens, L 3 - The third convex lens, L 4 - The fourth convex lens, M 1 -First reflector, M 2 - Second reflector, M 3 -The third reflector, OL-objective lens, SLM-spatial light modulator, CCD-camera, LED-illumination source, PC-computer terminal;

[0026] Figure 3 A schematic diagram of a single pump structure and a coupling coefficient variation curve used in the present invention;

[0027] Among them, (a) is a schematic diagram of the structure of three-waveguide pumping, in which the dark waveguide a is the incident waveguide, the light waveguide b is the middle straight waveguide, and the dark waveguide c is the output waveguide; (b) is a curve of the coupling coefficient between the incident waveguides a and b and the middle straight waveguide c, and the line type is a straight line; (c) is a cross-sectional example diagram of two coupling modes in space;

[0028] Figure 4 It is a cross-sectional schematic diagram and a microscope image of the close-packed waveguide unit cells of the present invention;

[0029] Wherein, (a) is a schematic cross-sectional view of a waveguide unit cell, the dark circle represents the first main waveguide 1, the light circle represents the second main waveguide 2, the dark triangle represents the first auxiliary waveguide 3, the light triangle represents the second auxiliary waveguide 4, the square waveguides correspond to the first straight waveguide 5 and the second straight waveguide 6, respectively, and the relative numbering changes of the waveguides are shown in the (i, j) coordinates; (b) is a cross-sectional microscope image of the Solis photon pump described in the present invention;

[0030] Figure 5 The diagram of the variation of the coupling coefficient of the waveguide unit cell and the simulated light intensity pumping curve of the present invention;

[0031] Among them, (a) is the coupling coefficient variation curve of two different three-step pumping devices, where κ 15 , κ 16 are the coupling coefficient curves of the first main waveguide 1 with the first straight waveguide 5 and the second straight waveguide 6 respectively; similarly, κ25 , κ 26 , κ 35 , κ 36 , κ 45 , κ 46 , respectively correspond to the coupling coefficient variation curves of the second main waveguide 2, the first auxiliary waveguide 3, and the second auxiliary waveguide 4 with the straight waveguides on both sides of the plane, and the above curves are all linear; (b) is a simulation curve of light intensity pumping when the test light is input from the first main waveguide 1 and the second main waveguide 2 of the device 1 defined by (a); (c) is a simulation curve of light intensity pumping when the test light is input from the first main waveguide 1 and the second main waveguide 2 of the device 2 defined by (a);

[0032] Figure 6 This is the energy distribution diagram of the output end face of the present invention;

[0033] Among them, after the 808nm vertically polarized test light is introduced, the energy distribution of the output end face is displayed; (a) the first main waveguide 1 and the second main waveguide 2 of device 1 are respectively introduced; (b) the first main waveguide 1 and the second main waveguide 2 of device 2 are respectively introduced; (c) the first main waveguide 1 and the second main waveguide 2 of the cascaded devices 1 and 2 are respectively introduced; (d) the first main waveguide 1 and the second main waveguide 2 of the cascaded devices 2 and 1 are respectively introduced. DETAILED DESCRIPTION

[0034] In order to clearly and completely describe the technical solution and its specific working process of the present invention, the specific implementation methods of the present invention are as follows in conjunction with the accompanying drawings of the specification:

[0035] Example 1

[0036] like Figure 1 As shown in (a), this embodiment provides a Solis photon pump array based on a two-dimensional non-Abelian and Le principle, which is composed of multiple waveguide unit cells stacked in a close-packed manner in the vertical propagation direction; wherein the multiple waveguide unit cells are all "vegetable basket" structures; the waveguide unit cells include a first main waveguide 1, a second main waveguide 2, a first auxiliary waveguide 3, a second auxiliary waveguide 4, a first straight waveguide 5 and a second straight waveguide 6; the first main waveguide 1 is located on the bottom surface of the "vegetable basket" structure, the second main waveguide 2 and the first auxiliary waveguide 3 are respectively located on the two side surfaces of the "vegetable basket" structure, the second auxiliary waveguide 4 is located on the handle surface of the "vegetable basket" structure that is symmetrical to the bottom surface, and the first straight waveguide 5 and the second straight waveguide 6 are respectively located on two mutually parallel side lines of the bottom surface of the "vegetable basket" structure, and their directions are the propagation direction.

[0037] The first main waveguide 1 in the plurality of waveguide unit cells constitutes a first rhombus grid that changes periodically along an oblique direction, and the second main waveguide 2 in the plurality of waveguide unit cells constitutes a second rhombus grid that changes periodically along an oblique direction. When observed along one of the 45-degree oblique lines, the first main waveguide 1 and the second main waveguide 2 appear alternately and the waveguides are collinear. The oblique line is defined as the change direction of the cell position number i, and another oblique line perpendicular to it is defined as the change direction of the position number j; any point in the first rhombus grid is marked as A ij , any point in the second diamond grid is marked as B ij ; When the test light is from any point A in the first diamond grid ij When input, it is transmitted to any point B in the second diamond grid through a finite number of couplings ij Output; conversely, the test light can also be output from any point B in the second diamond grid ij Transmit to any point A in the first diamond grid ij ; Among them, i and j are cell position numbers.

[0038] In this embodiment, the lattice spacing of the first main waveguide 1 in the first diamond grid and the second main waveguide 2 in the second diamond grid are both 48 μm; the interlaced layer spacing of the first diamond grid and the second diamond grid is 24 μm; the spacing between the first straight waveguide 5 and the second straight waveguide 6, that is, the side length d of the "basket" structure 0 is 34μm; the maximum coupling distance d 1 is 17μm, and the corresponding coupling coefficient is 0.0166rad / mm; the minimum coupling spacing d 2 is 5 μm, and the corresponding coupling coefficient is 2.8969 rad / mm; the propagation length of the one-step Solis pump is l tp The overall size of the unit cell is 34μm×34μm×14mm. The unit cells are densely packed in a two-dimensional plane perpendicular to the propagation direction and are simply directly connected in the propagation direction. The number of lateral periods of the device is n. x is 5, the number of longitudinal cycles n y = 3, Solis pumping step number n tp The device size is 3 and the overall size is 170 μm × 102 μm × 42 mm.

[0039] In this embodiment, the Solis pump array is three-step pumping, which is divided into three sections of 0-14mm, 14-28mm, and 28-42mm along the propagation direction; the coupling spacing between the first main waveguide 1 and the first straight waveguide 5 is 17μm in the first section and remains unchanged, decreases from 17μm to 5μm in the second section, rapidly increases to 29μm at the end of the section, and decreases from 29μm to 17μm in the third section; the coupling spacing between the second main waveguide 2 and the first straight waveguide 5 decreases from 17μm to 5μm in the first section, increases from 5μm to 17μm in the second section, and remains unchanged at 17μm in the third section; the coupling spacing between the first auxiliary waveguide 3 and the first straight waveguide 5 increases from 5μm to 17μm in the first section, remains unchanged at 17μm in the second section, and increases from 17μm to 29μm in the third section. Since the first straight waveguide 5 and the second straight waveguide 6 are parallel to each other and the spacing between them is constant at 34 μm, the coupling spacing between the above waveguide and the second straight waveguide 6 can be directly obtained by subtracting the coupling spacing from the first straight waveguide 5 . Figure 5 (a) shows the relationship between the change in coupling coefficient and the change in coupling spacing, and the coupling coefficient changes in a linear manner.

[0040] In this embodiment, the Solis photon pump array is prepared by femtosecond laser direct writing technology, and the specific steps are as follows:

[0041] A1. Fix the clean sample on the sample stage, lower the objective lens OL, make the laser focus close to the sample surface, and observe the focus morphology collected by CCD in real time through the computer; adjust the leveling knob so that the spot image remains unchanged when the sample motion control platform moves along the X-axis and Y-axis respectively, indicating that the sample surface is relatively parallel to the movement direction of the sample stage and perpendicular to the incident direction of the laser, that is, the sample stage has been leveled;

[0042] A2. Move the sample to the processing starting point, lower the objective lens to the appropriate processing depth, adjust the laser power to the appropriate level, load the designed Solis photon pump processing program into the translation stage, and start processing;

[0043] A3. After processing, remove the sample, cut off 1 mm from both ends of the sample with a diamond cutter, polish the incident surface and the output surface for 20 minutes each using corundum powder and a polisher, and after removing excess powder, obtain the Solis photon pump array based on the two-dimensional non-Abelian and Le principle.

[0044] The femtosecond laser wavelength used is 1030nm, the pulse width is 239fs, and the repetition frequency is 1MHz; the processing laser power is 230mW, the scanning speed is 40mm / s, the structure center depth is 190μm below the surface, and the size of the Corning brand glass sample used is 10cm×2.5cm×1.1cm.

[0045] Example 2

[0046] The present embodiment provides a pumping method for a Solis photon pump array based on a two-dimensional non-Abelian and Le principle, specifically comprising: when the test light is input from the first main waveguide 1 of a unit cell (i, j), it will be pumped to the second main waveguide 2 of the same unit cell via the first straight waveguide 5; when the test light is input from the second main waveguide 2 of the unit cell (i, j), it will be pumped to the first auxiliary waveguide 3 of the cell (i, j-1) in turn, and then pumped to the first main waveguide 1 of the cell (i, j-1), thereby realizing energy exchange between the first main waveguide 1 and the second main waveguide 2.

[0047] In this embodiment, the structure and processing parameters of the Solis photon pump involved are the same as those in Embodiment 1. By solving the beam propagation equation using MATLAB, the light propagation process inside the sample can be simulated and calculated. Figure 5 To test the structure, the output light of the 808nm continuous laser is first adjusted to vertical polarization through a polarizer, and then focused on the polished sample end face through a 20x objective lens. The focus position is observed through the CCD, and the laser focus is aligned with the main waveguide 1 or 2 to stimulate the corresponding pumping process; the light intensity distribution morphology of the output surface is collected using a 40x objective lens and projected onto a mode analyzer to obtain the pumping result of the light through the Solis photon pump.

[0048] In this embodiment, Figure 6 As shown in (a), when light is input from the first main waveguide 1, the light intensity almost entirely appears in the second main waveguide 2 at the lower left corner; when light is input from the second main waveguide 2, the light intensity almost entirely appears in the second main waveguide 2 at the lower right corner; the above results are consistent with the design objectives and Figure 5 The endpoint results of the curve described in (b) are consistent.

[0049] Figure 6 In the output end face light intensity distribution diagram shown, the circular dotted line is the first diamond grid and the second diamond grid composed of the first main waveguide 1 or the second main waveguide 2; the triangular dotted line indicates the first auxiliary waveguide 3 or the second auxiliary waveguide 4 involved in the pumping process; the white arrow shows the pumping direction of the light after finite coupling; the "basket"-shaped frame selects the unit cells involved in the pumping process shown in the picture, and has been marked by the position coordinates (i, j).

[0050] Example 3

[0051] This embodiment provides another Solis photon pumping method based on the two-dimensional non-Abelian and Le principle, including: when the test light is input from the first main waveguide 1 of the unit cell (i, j), it will be pumped to the second auxiliary waveguide 4 of the cell (i+1, j) in sequence, and then pumped to the second main waveguide 2 of the cell (i+1, j+1); when the test light is input from the second main waveguide 2 of the unit cell (i, j), it will be pumped to the first main waveguide 1 via the second straight waveguide 6 of the cell (i-1, j), thereby realizing energy exchange between the first main waveguide 1 and the second main waveguide 2.

[0052] In this embodiment, the maximum coupling spacing, the minimum coupling spacing, the number of lateral and longitudinal periods, the number of pumping steps, the propagation length of single-step pumping, and the total size of the device are the same as those in Embodiment 1;

[0053] In this embodiment, the Solis pump is a three-step pump, which is divided into three sections of 0-14mm, 14-28mm, and 28-42mm along the propagation direction; the coupling spacing between the first main waveguide 1 and the second straight waveguide 6 decreases from 17μm to 5μm in the first section, increases from 5μm to 17μm in the second section, and remains unchanged at 17μm in the third section; the coupling spacing between the second main waveguide 2 and the second straight waveguide 6 remains unchanged at 17μm in the first section, decreases from 17μm to 5μm in the second section, rapidly increases to 29μm at the end of the section, and decreases from 29μm to 17μm in the third section; the coupling spacing between the second auxiliary waveguide 4 and the second straight waveguide 6 increases from 5μm to 17μm in the first section, remains unchanged at 17μm in the second section, and increases from 17μm to 29μm in the third section. Since the first straight waveguide 5 and the second straight waveguide 6 are parallel to each other and the spacing between them is constant at 34 μm, the coupling spacing between the above waveguide and the first straight waveguide 5 can be directly obtained by subtracting the coupling spacing between the above waveguide and the second straight waveguide 6 . Figure 5 (a) shows the relationship between the change in coupling coefficient and the change in coupling spacing, and the coupling coefficient changes in a linear manner.

[0054] In this embodiment, the Solis photon pump array is prepared by femtosecond laser direct writing technology, and the femtosecond laser parameters, processing parameters, sample parameters, etc. used are the same as those in Example 1.

[0055] In this embodiment, Figure 6 As shown in (b), when light is input from the first main waveguide 1, the light intensity almost entirely appears in the second main waveguide 2 at the upper left corner; when light is input from the second main waveguide 2, the light intensity almost entirely appears in the second main waveguide 2 at the lower left corner; the above results are consistent with the design objectives and Figure 5 The endpoint results of the curve described in (b) are consistent.

[0056] Example 4

[0057] The present embodiment provides a cascading method for a Thouless photon pump array with non-Abelian characteristics based on a two-dimensional non-Abelian harmony principle, comprising: in a first case, the device 1 described in Example 1 and the device 2 described in Example 2 are cascaded front and back, and when the test light is input from the first main waveguide 1, it will be pumped to the first main waveguide 1 of the lower left corner cell, and when it is input from the second main waveguide 2, it will be pumped to the second main waveguide 2 of the upper right corner cell; in a second case, the device 2 described in Example 2 and the device 1 described in Example 1 are cascaded front and back, and when the test light is input from the first main waveguide 1, it will be pumped to the first main waveguide 1 of the upper right corner cell, and when it is input from the second main waveguide 2, it will be pumped to the second main waveguide 2 of the lower left corner cell.

[0058] In this embodiment, all design and processing parameters of devices 1 and 2 are the same as those of embodiments 1 and 2. Since both cells have a "basket" structure, the devices can be integrated by direct front-to-back connection without excessive modification.

[0059] In this embodiment, the test light is input from the first main waveguide 1 and the second main waveguide 2, and the final pump result light intensity energy distribution is as follows: Figure 6 As shown in (c) and (d). The device completes the above-mentioned pumping process with an efficiency of more than 95%, and there is no stray light in the surrounding waveguide, showing a good transmission effect; the connection order of the devices will affect the final pumping result, which is also confirmed by the experiment, indicating that the Solis photon pump array has a non-commutative characteristic, that is, a non-Abelian characteristic. The non-Abelian characteristic is of great significance to complex topological optical computing, proving that this method paves the way for large-scale three-dimensional integrated high-speed optical computing chips based on femtosecond laser direct writing.

[0060] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0061] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0062] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A Thouless photon pump array based on a two-dimensional non-Abelian principle, characterized in that: The Solis photon pump array is formed by stacking a plurality of waveguide unit cells in a close-packed manner in a vertical propagation direction; wherein the plurality of waveguide unit cells are all "vegetable basket" structures; the waveguide unit cells include a first main waveguide (1), a second main waveguide (2), a first auxiliary waveguide (3), a second auxiliary waveguide (4), a first straight waveguide (5) and a second straight waveguide (6); the first main waveguide (1) is located on the bottom surface of the "vegetable basket" structure, the second main waveguide (2) and the first auxiliary waveguide (3) are respectively located on two side surfaces of the "vegetable basket" structure, the second auxiliary waveguide (4) is located on a handle surface of the "vegetable basket" structure that is symmetrical to the bottom surface, and the first straight waveguide (5) and the second straight waveguide (6) are respectively located on two mutually parallel side lines of the bottom surface of the "vegetable basket" structure, and their directions are the propagation direction.

2. A two-dimensional non-Abelian and Le principle-based Thouless photon pump array as claimed in claim 1, characterized in that: The first main waveguide (1) in the plurality of waveguide unit cells forms a first rhombus grid that changes periodically along an oblique direction, and the second main waveguide (2) in the plurality of waveguide unit cells forms a second rhombus grid that changes periodically along an oblique direction. When observed along one of the 45-degree oblique lines, the first main waveguide (1) and the second main waveguide (2) appear alternately and the waveguides are collinear. The oblique line is defined as the direction of change of the cell position number i, and another oblique line perpendicular to the oblique line is defined as the direction of change of the position number j. Any point in the first rhombus grid is marked as A. ij , any point in the second diamond grid is marked as B ij ; When the test light is from any point A in the first diamond grid ij When input, it is transmitted to any point B in the second diamond grid through a finite number of couplings ij Output; conversely, the test light can also be output from any point B in the second diamond grid ij Transmit to any point A in the first diamond grid ij ; Among them, i and j are cell position numbers.

3. The Thouless photon pump array based on the two-dimensional non-Abelian principle as claimed in claim 1, characterized in that: The lattice spacing range of the first diamond grid and the second diamond grid is 40-160λ, and the interlaced layer spacing range of the first diamond grid and the second diamond grid is 20-80λ; the spacing d0 between the first straight waveguide (5) and the second straight waveguide (6) is 30-120λ; wherein λ is the wavelength of the pump test excitation light.

4. The Thouless photon pump array based on the two-dimensional non-Abelian principle as claimed in claim 1, characterized in that: The first main waveguide (1), the second main waveguide (2), the first auxiliary waveguide (3), and the second auxiliary waveguide (4) evolve in a straight line or a curve in the planes where they are located, and in the evolution process, the spatial distance between the first main waveguide (1), the second main waveguide (2), the first auxiliary waveguide (3), and the second auxiliary waveguide (4) and the first straight waveguide (5) and the second straight waveguide (6) at the edge of the plane where they are located is the coupling spacing, wherein the selection range of the maximum coupling spacing d1 is 15-115λ, the selection range of the minimum coupling spacing d2 is 5-15λ, and d1>d2; since the first straight waveguide (5) and the second straight waveguide (6) are parallel, there exists a relationship d1+d2=d0.

5. The Thouless photon pump array based on the two-dimensional non-Abelian principle as claimed in claim 1, characterized in that: The overall size of the waveguide unit cell is d0×d0×l tp , where l tp is the propagation length of the one-step Solis pump, ranging from 10 4 -10 5 λ; the unit cells are stacked in a two-dimensional plane in the vertical propagation direction and directly connected in the propagation direction, and the number of lateral periods of the cells of the composed device is n x , the number of longitudinal periods is n y , the number of pumping steps in the propagation direction is n tp , then the overall size of the device is n x d0×n y d0×n tp l tp .

6. A pumping method for a two-dimensional non-Abelian and Le principle-based Thouless photon pump array as claimed in claim 1, characterized in that: The specific contents include the following: When the test light is input from the first main waveguide (1) of the waveguide unit cell, it will be pumped to the second main waveguide (2) of the same waveguide unit cell via the first straight waveguide (5); when the test light is input from the second main waveguide (2) of the waveguide unit cell, it will be pumped to the first auxiliary waveguide (3) of the lower right corner cell in sequence, and then pumped to the first main waveguide (1) of the cell, thereby realizing energy exchange between the first main waveguide (1) and the second main waveguide (2).

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