Non-uniform power divider based on photonic crystal pseudo magnetic field
Through a non-uniform power distributor based on the pseudomagnetic field of the photonic crystal, asymmetric light field distribution is achieved using a honeycomb lattice photonic crystal structure, which solves the problems of large size and high power consumption of traditional power distributors, and realizes efficient non-uniform power distribution, which is suitable for high-density photonic integration and low-latency communication.
Patent Information
- Application Number
- CN202510767987.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-10
- Publication Date
- 2025-08-08
AI Technical Summary
Traditional power dividers are large in size, high in power consumption, slow response speed and poor integration compatibility, making it difficult to meet the needs of high-density photonic integration and low-latency communication.
A non-uniform power distributor based on the pseudomagnetic field of a photonic crystal is designed. By constructing a photonic crystal with a honeycomb lattice structure, a non-uniform light field is formed using the asymmetric distribution of the equilateral triangle hole array, and the power distribution of 1:2 and 1:3 is achieved, with a loss less than 2dB.
Inhomogeneous power distribution is achieved in the wavelength range of 1530-1580nm, and the photonic crystal region length is less than 100μm, meeting the needs of high-density photonic integration and low-latency communication, and low loss.
Smart Images
Figure CN120447139A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a technology in the field of optical communications, in particular to a non-uniform power divider based on photonic crystal pseudomagnetic field. Background Art
[0002] Power dividers, core passive components in optical networks and photonic integrated circuits (PICs), distribute input optical signals to multiple output ports in a specific ratio. Traditional power dividers (such as Y-splitters and multimode interference couplers) are typically based on fixed structures. Non-uniform solutions often suffer from large size, high power consumption, slow response, and poor integration compatibility, making them difficult to meet the demands of high-density photonic integration and low-latency communication scenarios. Summary of the Invention
[0003] To address the inability of existing technologies to achieve non-uniform power distribution, the present invention proposes a non-uniform power divider based on photonic crystal pseudomagnetic field. In the case of fundamental mode input, 1:2 and 1:3 non-uniform power distribution is achieved by constructing the lattice size. Within the wavelength range of 1530-1580nm, the outputs of both ports meet specific ratios, the loss is less than 2dB, and the photonic crystal region length is less than 100μm.
[0004] The present invention is achieved through the following technical solutions:
[0005] The present invention relates to a non-uniform power divider based on a pseudomagnetic field of a photonic crystal, comprising: a buried oxide layer, a silicon layer and an upper cladding layer arranged in sequence from bottom to top, wherein: the silicon layer is a front-end straight waveguide obtained by etching, a photonic crystal with a honeycomb lattice structure and two output-end straight waveguides. Under the action of the pseudomagnetic field, incident light passes through the photonic crystal to achieve non-uniform power distribution at the two output ends.
[0006] The honeycomb lattice structure refers to: an array of two equilateral triangular holes with different side lengths etched on a photonic crystal. After the incident light is input into the photonic crystal, a light field propagation path including a straight waveguide region and a curved waveguide region is formed therefrom. Among them, the different triangular hole sizes of the incident light in the straight waveguide region form an asymmetric light field, and the incident light is split into output lights of unequal power in the curved waveguide region.
[0007] The two equilateral triangular hole arrays include: a first equilateral triangular array with its vertex angle facing the input end and a second equilateral triangular array with its vertex angle facing the output end, which are staggered in the vertical direction. The first and second equilateral triangular arrays have the same area on the symmetry axis of the photonic crystal from the input end to the output end, forming a non-disturbance layer. The side lengths of the equilateral triangular holes along the non-disturbance layer on both sides of the photonic crystal change accordingly as the distance from the symmetry axis increases.
[0008] The side length of the equilateral triangle hole changes accordingly with the increase of the distance from the symmetry axis, specifically referring to: the change in the side length of the triangle in the first equilateral triangle array in any vertical direction The change in the length of the triangle side in the corresponding second equilateral triangle array Match.
[0009] For example: Take the intersection of the input end and the symmetry axis as the origin, and the symmetry axis is 0, ,in: is the gradient of the triangle hole size change, is the photonic crystal lattice constant, is the ordinate of the center of the triangular hole, is the ordinate of the center of the triangular hole in the undisturbed layer, is the rate of change, is the undisturbed layer index, that is, the ratio of the side length of the equal-sided triangular hole in the undisturbed layer to the lattice constant of the photonic crystal.
[0010] The undisturbed layer index is preferably 0.5.
[0011] The vertical coordinates of the center of the triangular hole in the non-perturbed layer include: the parametric equation in the area I on one side of the symmetry axis , the parametric equation in region II on the other side of the symmetry axis is , where: the horizontal axis , is the number of horizontal periods, K is the shape parameter used to adjust the inclination of the curve, is the photonic crystal lattice constant.
[0012] The lattice constant of the honeycomb lattice structure It is 0.46μm.
[0013] The honeycomb lattice structure has a change rate on both sides of the symmetry axis for controlling the port output power ratio. Specifically, when the change rate of the triangular hole size on one side of the symmetry axis, i.e., in region I, is Equal to the other side of the symmetry axis, that is, the rate of change of the triangular hole size in region II is When , the light field energy is evenly distributed in the two regions; when When the light field energy is mainly concentrated in region II, When , the light field energy is mainly concentrated in region I.
[0014] Technical Effects
[0015] This invention achieves non-uniform power distribution on a silicon-based photonic platform using a photonic crystal with a honeycomb lattice as its unit cell. The linear variation of the triangular apertures in the honeycomb lattice generates a pseudomagnetic field, which provides topological protection for light transmission within the lattice. Furthermore, the non-uniform distribution of the light field is controlled by designing the variation rate of the triangular apertures in regions I and II. Compared to existing technologies, this invention can achieve different power distribution ratios on a silicon-based photonic platform, such as 1:2 or 1:3. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of the structure of the present invention;
[0017] In the figure: buried oxide layer 1, silicon layer 2, upper cladding layer 3, front end straight waveguide 4, photonic crystal 5, output end straight waveguide 6, straight waveguide region 501 and curved waveguide region 502 of the optical field path;
[0018] Figure 2 is a SEM image of a photonic crystal;
[0019] In the figure: (b) (c) (d) are respectively partial enlarged schematic diagrams of (a), and the purple shaded area is the light field path;
[0020] Figure 3 (a) Magnetic field distribution during fundamental mode transmission simulation of a power divider with a power ratio of 1:2. Figure 3 (b) Schematic diagram of port transmittance during fundamental mode transmission in simulation and experimental tests of a power divider with a power ratio of 1:2;
[0021] Figure 4 (a) Magnetic field distribution during fundamental mode transmission simulation of a power divider with a power ratio of 1:3. Figure 4 (b) Schematic diagram of port transmittance during fundamental mode transmission in simulation and experimental test of a power divider with a power ratio of 1:3. DETAILED DESCRIPTION
[0022] like Figure 1 As shown, this embodiment relates to a non-uniform power divider based on a photonic crystal pseudomagnetic field, comprising: a buried oxide layer 1, a silicon layer 2 and an upper cladding layer 3 arranged in sequence from bottom to top, wherein: the silicon layer 2 is a front end straight waveguide 4 obtained by etching, a photonic crystal 5 and two output end straight waveguides 6.
[0023] The buried oxide layer 1 is silicon dioxide, and its thickness is 3 μm.
[0024] The thickness of the silicon layer 2 is 220 nm.
[0025] The upper cladding layer 3 is made of silicon dioxide and has a thickness of 1 μm.
[0026] As shown in FIG2 , the photonic crystal 5 is based on a honeycomb lattice and includes region I and region II. The triangular holes in the two regions have different change rates to form an asymmetric light field. Light is input along the straight waveguide of the photonic crystal and output from the curved waveguide of the photonic crystal.
[0027] The width of the front-end straight waveguide 4 and the output-end straight waveguide 6 is 3.2 μm. Under this width, the mode field size in the waveguide can match the mode field size in the photonic crystal, reducing energy leakage and improving transmittance.
[0028] The transverse period of the photonic crystal 5 is 125, and the longitudinal period is 33.
[0029] The path of the non-perturbation layer in the curved waveguide 502 of the photonic crystal 5 is determined by the parameter K. By adjusting the value of K, the degree of curvature of the curve can be controlled.
[0030] The change rates of the triangular holes in the honeycomb lattice in the region I and region II are and ,when When , the light field energy is evenly distributed in the two regions. When the light field energy is mainly concentrated in region II, When , the light field energy is mainly concentrated in region I.
[0031] After specific experiments, the FDTD (3D finite difference time domain method) tool based on Lumerical software was used. Figure 1 The simulation model of the structure shown in the figure is built, and the simulation area is meshed. The main optimization parameters include the photonic crystal bending waveguide parameter K and the change rate of the triangular hole size in area I and area II. K=10 is designed. Under this parameter, the photonic crystal loss is small. , When the values are 0.0365 and 0.04 respectively, a 1:2 power divider can be realized in the wavelength range of 1530-1580nm. The results are as follows Figure 3 As shown by the dotted line; when , When the values are 0.0343 and 0.04 respectively, a 1:3 power divider can be realized in the wavelength range of 1530-1580nm. The results are as follows Figure 4 The simulation results of the two power dividers show that the loss is less than 2.2dB.
[0032] Based on the above simulation, the specific preparation of the non-uniform power divider was carried out, including: after the cleaned SOI wafer (the upper silicon layer thickness of the SOI wafer is 220 nm and the buried oxide layer thickness is 3 μm), the designed photonic crystal pattern and input and output straight waveguide patterns are transferred to the SOI wafer by electron beam lithography. After development, 220nm is etched using a deep silicon etcher to prepare the photonic crystal area, input and output straight waveguides. After cleaning again, the wafer is coated and baked, and the grating pattern is transferred to the SOI wafer by electron beam lithography. After development, 70nm is etched to prepare the grating. Then, 1μm of silicon dioxide is deposited on the upper surface to complete the sample preparation.
[0033] The non-uniform power divider prepared above was tested and the following results were obtained: Figure 3 The power distribution curve shown by the solid line in the middle shows that the power difference between the two output ports is 3dB; the 1:3 power divider obtained by the test is as follows Figure 4 As shown by the solid line, the output difference between the two ports is 4.7dB, which is consistent with the simulation results.
[0034] Compared with the existing technology, the present invention controls the asymmetric distribution of the light field by designing the change rate of the triangular holes in area I and area II, thereby realizing asymmetric transmission of optical power. The power dividers with power ratios of 1:2 and 1:3 were simulated and experimentally tested, and the results were consistent, with the loss less than 2.2dB.
[0035] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principles and purpose of the present invention. The scope of protection of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. All implementation schemes within its scope shall be subject to the constraints of the present invention.
Claims
1. A non-uniform power divider based on photonic crystal pseudomagnetic field, characterized in that: include: The buried oxide layer, silicon layer and upper cladding layer are arranged in sequence from bottom to top. Among them, the silicon layer is etched to form a front straight waveguide, a photonic crystal with a honeycomb lattice structure, and two output straight waveguides. After the incident light passes through the photonic crystal to form a pseudomagnetic field, non-uniform power distribution is achieved at the two output ends. The honeycomb lattice structure refers to: an array of two equilateral triangular holes with different side lengths etched on a photonic crystal. After the incident light is input into the photonic crystal, a light field propagation path including a straight waveguide region and a curved waveguide region is formed therefrom. Among them, the different triangular hole sizes of the incident light in the straight waveguide region form an asymmetric light field, and the incident light is split into output lights of unequal power in the curved waveguide region.
2. The non-uniform power divider based on photonic crystal pseudomagnetic field according to claim 1, characterized in that: The two equilateral triangular hole arrays include: a first equilateral triangular array with its vertex angle facing the input end and a second equilateral triangular array with its vertex angle facing the output end, which are staggered in the vertical direction. The first and second equilateral triangular arrays have the same area on the symmetry axis of the photonic crystal from the input end to the output end, forming a non-disturbance layer. The side lengths of the equilateral triangular holes along the non-disturbance layer on both sides of the photonic crystal change accordingly as the distance from the symmetry axis increases.
3. The non-uniform power divider based on photonic crystal pseudomagnetic field according to claim 1 or 2, characterized in that: The side length of the equilateral triangle hole changes accordingly with the increase of the distance from the symmetry axis, specifically referring to: the change in the side length of the triangle in the first equilateral triangle array in any vertical direction The change in the length of the triangle side in the corresponding second equilateral triangle array Match.
4. The non-uniform power divider based on photonic crystal pseudomagnetic field according to claim 3, characterized in that: The intersection of the input end and the symmetry axis is the origin, and the symmetry axis is 0, ,in: is the gradient of the triangle hole size change, is the photonic crystal lattice constant, is the ordinate of the center of the triangular hole, is the ordinate of the center of the triangular hole in the undisturbed layer, is the rate of change, is the undisturbed layer index.
5. The non-uniform power divider based on photonic crystal pseudomagnetic field according to claim 2, 3 or 4, characterized in that: The vertical coordinates of the center of the triangular hole in the non-perturbation layer include: the parametric equation in the area I on one side of the symmetry axis , the parametric equation in region II on the other side of the symmetry axis is , where: the horizontal axis , is the number of horizontal periods, K is the shape parameter used to adjust the inclination of the curve, is the photonic crystal lattice constant.
6. The non-uniform power divider based on photonic crystal pseudomagnetic field according to claim 2, 3 or 4, characterized in that: The honeycomb lattice structure has a change rate on both sides of the symmetry axis for controlling the port output power ratio. Specifically, when the change rate of the triangular hole size on one side of the symmetry axis, i.e., in region I, is Equal to the other side of the symmetry axis, that is, the rate of change of the triangular hole size in region II is When , the light field energy is evenly distributed in the two regions; when When the light field energy is mainly concentrated in region II, When , the light field energy is mainly concentrated in region I.