Beam splitter, optical module, optical chip and electronic equipment

Abstract

The embodiment of the invention provides a beam splitter, an optical module, an optical chip and electronic equipment, which are applied to the technical field of optical communication. The beam splitter comprises a combining end, a tapered waveguide structure and a plurality of splitting ends. The tapered waveguide structure comprises at least two trapezoidal waveguide structures and at least one rectangular waveguide structure. Wherein the at least two trapezoidal waveguide structures are cascaded, and for two adjacent trapezoidal waveguide structures in the at least two trapezoidal waveguide structures, the two adjacent trapezoidal waveguide structures are coupled based on one rectangular waveguide structure in the at least one rectangular waveguide structure. The combining end is coupled with the first-stage trapezoidal waveguide structure in the at least two cascaded trapezoidal waveguide structures, and the plurality of branching ends are coupled with the last-stage trapezoidal waveguide structure in the at least two cascaded trapezoidal waveguide structures. The gradual change waveguide structure is optimized in the mode, so that the process preparation difficulty of the gradual change waveguide structure is reduced, and the algorithm search space is improved.

Description

Technical Field

[0001] This application relates to the field of optical communication technologies, and in particular, to a beam splitter, an optical module, an optical chip, and an electronic device. Background Art

[0002] An optical waveguide is a dielectric structure that guides light waves to propagate therein, also known as a dielectric optical waveguide. Dividing and optimizing the optical waveguide structure is one of the important means to improve the performance of optical waveguide devices. However, due to limitations in the manufacturing process, it is difficult to implement the sharp corner structures generated in the design of related optical waveguide structures during the manufacturing process, and the dimensions of the optical waveguide structure are single, which is not conducive to the search of algorithms, and thus it is difficult to meet the design requirements for the performance of optical waveguides. Summary of the Invention

[0003] Embodiments of this application provide a beam splitter, an optical module, an optical chip, and an electronic device. By optimizing the optical waveguide structure, the manufacturing difficulty of the optical waveguide is reduced, and the algorithm search space is improved.

[0004] To achieve the above object, the embodiments of this application adopt the following technical solutions:

[0005] In a first aspect, a beam splitter is provided, including a multiplexing end, a tapered waveguide structure, and a plurality of demultiplexing ends. The tapered waveguide structure includes at least two trapezoidal waveguide structures and at least one rectangular waveguide structure. Among them: at least two trapezoidal waveguide structures are cascaded, and for two adjacent trapezoidal waveguide structures among the at least two trapezoidal waveguide structures, coupling between the two adjacent trapezoidal waveguide structures is achieved based on one rectangular waveguide structure among the at least one rectangular waveguide structure. The multiplexing end is coupled to the first-stage trapezoidal waveguide structure among the at least two cascaded trapezoidal waveguide structures, and the plurality of demultiplexing ends are coupled to the last-stage trapezoidal waveguide structure among the at least two cascaded trapezoidal waveguide structures.

[0006] In the embodiments of this application, for two adjacent trapezoidal waveguide structures among the at least two trapezoidal waveguide structures in the beam splitter, by inserting a section of rectangular waveguide structure between the two adjacent trapezoidal waveguide structures, coupling between the two adjacent trapezoidal waveguide structures is achieved. The introduction of the rectangular waveguide structure avoids the sharp corner structures that may be generated in the method of directly coupling two adjacent trapezoidal waveguide structures, optimizes the difficulty in the division method of the tapered waveguide structure, and improves the process tolerance of the prepared tapered waveguide structure. At the same time, the introduction of the rectangular waveguide structure also increases the variable dimension, thereby improving the algorithm search space, better exerting the global search ability of the optimization algorithm, and further improving the performance of the beam splitter.

[0007] In a possible implementation, for two adjacent cascaded trapezoidal waveguide structures, any of the following coupling methods is satisfied: the upper base of the front-stage trapezoidal waveguide structure is coupled to the lower base of the rear-stage trapezoidal waveguide structure through a rectangular waveguide structure. Or, the upper base of the front-stage trapezoidal waveguide structure is coupled to the upper base of the rear-stage trapezoidal waveguide structure through a rectangular waveguide structure. Or, the lower base of the front-stage trapezoidal waveguide structure is coupled to the upper base of the rear-stage trapezoidal waveguide structure through a rectangular waveguide structure. Or, the lower base of the front-stage trapezoidal waveguide structure is coupled to the lower base of the rear-stage trapezoidal waveguide structure through a rectangular waveguide structure. In the embodiments of the present application, by providing various cascading methods for two adjacent trapezoidal waveguide structures, the flexibility and diversity of the beam splitter design are increased.

[0008] In a possible implementation, iterative calculations are performed on the structural parameters of the beam splitter, and the calculation results of the iterative calculations are verified based on verification conditions to determine the structural parameters from the calculation results. The structural parameters include at least one of the following: the upper base length of the trapezoidal waveguide structure, the lower base length of the trapezoidal waveguide structure, the height of the trapezoidal waveguide structure, the length of the rectangular waveguide structure, the width of the rectangular waveguide structure, the height of the rectangular waveguide structure, and the number of splitting ends. In the embodiments of the present application, through iterative calculations on the structural parameters of the beam splitter and verification of the calculation results of the iterative calculations based on verification conditions to determine the structural parameters from the calculation results, a simulation reverse design method is used to exert the advantage of high flexibility in reverse design. At the same time, by introducing more structural parameters, the search dimension of the optimization algorithm is increased, making the operation process have a faster convergence speed and a better convergence effect.

[0009] In a possible implementation, iterative calculations are performed on the structural parameters of the beam splitter, including: performing iterative calculations on the structural parameters of the beam splitter based on the particle swarm optimization algorithm. In the embodiments of the present application, by using the particle swarm optimization algorithm to perform iterative calculations on the structural parameters of the beam splitter, the rapid convergence of the structural parameters to be optimized is achieved.

[0010] In a possible implementation, performing iterative calculations on the structural parameters of the beam splitter based on the particle swarm optimization algorithm includes: constructing the initial position variable and the initial velocity variable of the particles in the particle swarm optimization algorithm according to the structural parameters of the beam splitter. According to the initial position variable, the initial velocity variable, and the iterative update relationship of the particle swarm optimization algorithm, the updated position variable and the updated velocity variable are obtained. According to the position variable and the velocity variable, the output result of the beam splitter is obtained. The position variable includes the initial position variable and the updated position variable, and the velocity variable includes the initial velocity variable and the updated velocity variable.

[0011] In a possible implementation, the expression of the initial position variable is:

[0012] X i= [x1, x2, x3, …, x n

[0013] The expression for the initial velocity variable is:

[0014]

[0015] The expression for the updated position variable is:

[0016]

[0017] The expression for the updated velocity variable is:

[0018]

[0019] Where, X i represents the initial position variable of the i-th particle, and i represents the particle sequence number. x n represents the structural parameter, n = 1, 2, …, N, N represents the number of independent variables, and n represents the independent variable sequence number. V i represents the initial velocity variable of the i-th particle. v n represents the velocity of change of x n d = 1, 2, 3, …, K, K represents the number of iterations, and d represents the iteration sequence number. V i d represents the velocity variable of the i-th particle after the d-th iteration update. represents the position variable of the i-th particle after the d-th iteration update. w, c1, r1, c2, and r2 represent coefficients. represents the historical optimal position searched by the i-th particle after the d-th iteration. g best d represents the historical optimal position of the population in the d-th iteration.

[0020] In a possible implementation manner, the trapezoidal waveguide structure is an isosceles trapezoidal waveguide structure.

[0021] In a possible implementation manner, the verification condition is: verifying the calculation result of the iterative calculation based on the following first verification formula, and taking the calculation result that satisfies the first verification formula as the determined structural parameter. The expression of the first verification formula is as follows:

[0022]

[0023] Where, FOM1 represents the first verification formula, M represents the number of shunt ports, T represents the number of optical wave wavelengths, P m (λ t ) is the actual output power of the m-th shunt port at the t-th wavelength, and P m represents the target output power of the m-th shunt port.​

[0024] In a possible implementation, the beam splitter is a multi-way equal-splitting optical power splitter, and P m = 1 / M.

[0025] In a possible implementation, the trapezoidal waveguide structure is a non-isosceles trapezoidal waveguide structure.

[0026] In a possible implementation, the verification condition is: verifying the calculation result of the iterative calculation based on the following second verification formula, and taking the calculation result that satisfies the second verification formula as the determined structural parameter. The expression of the second verification formula is as follows:

[0027]

[0028] where FOM2 represents the second verification formula, M represents the number of splitting ends, T represents the number of optical wave wavelengths, and P m (λ t ) is the actual output power of the m-th splitting end at the t-th wavelength, and P m represents the target output power of the m-th splitting end.

[0029] In a possible implementation, the rectangular waveguide structure is a sub-wavelength structure. In the embodiments of the present application, by adopting the sub-wavelength structure, the process preparation difficulty of the tapered waveguide structure is reduced, and the process tolerance of the prepared tapered waveguide structure is improved. At the same time, by increasing the variable dimension, the algorithm search space is increased, and the global search ability of the optimization algorithm is better exerted, thereby improving the performance of the beam splitter.

[0030] In a possible implementation, the beam splitter is a wavelength division multiplexer.

[0031] In a second aspect, an optical module is provided, including a mounting substrate and a beam splitter. The beam splitter is disposed on the mounting substrate. The beam splitter includes a combining end, a tapered waveguide structure, and a plurality of splitting ends. The tapered waveguide structure includes at least two trapezoidal waveguide structures and at least one rectangular waveguide structure. Among them: at least two trapezoidal waveguide structures are cascaded, and for two adjacent trapezoidal waveguide structures among the at least two trapezoidal waveguide structures, coupling is achieved between the two adjacent trapezoidal waveguide structures based on one rectangular waveguide structure among the at least one rectangular waveguide structure. The combining end is coupled to the first-stage trapezoidal waveguide structure among the at least two cascaded trapezoidal waveguide structures, and the plurality of splitting ends are coupled to the last-stage trapezoidal waveguide structure among the at least two cascaded trapezoidal waveguide structures.

[0032] In a third aspect, an optical chip is provided, including a mounting substrate and any beam splitter as in the first aspect. The beam splitter is disposed on the mounting substrate.

[0033] In a fourth aspect, an electronic device is provided, comprising: a controller and the optical module according to the second aspect, the controller being coupled to the optical module, or the controller and the optical chip according to the third aspect, the controller being coupled to the optical chip.

[0034] Regarding the technical principles and beneficial effects of the second, third and fourth aspects mentioned above, please refer to the relevant description of the first aspect mentioned above, and no further details will be given here. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The structure of an optical power splitter provided in the embodiment of the present application Figure One ;

[0036] Figure 2 Another optical power splitter structure provided in the embodiment of the present application Figure Two ;

[0037] Figure 3 An optical waveguide topology structure provided in the embodiment of the present application Figure One ;

[0038] Figure 4 Another structure of an optical power splitter provided in the embodiment of the present application Figure Three ;

[0039] Figure 5 Another structure of an optical power splitter provided in the embodiment of the present application Figure Four ;

[0040] Figure 6 The structure of a beam splitter provided in an embodiment of the present application Figure One ;

[0041] Figure 7 Another optical waveguide topology provided in the embodiment of the present application Figure Two ;

[0042] Figure 8 Another optical waveguide topology structure provided in the embodiment of the present application Figure Three ;

[0043] Figure 9 Another beam splitter structure provided in the embodiment of the present application Figure Two ;

[0044] Figure 10 A flowchart of an optimization method provided in an embodiment of the present application;

[0045] Figure 11 Another optical waveguide topology structure provided in the embodiment of the present application Figure Four ;

[0046] Figure 12Another structure of the beam splitter provided by the embodiments of the present application Figure Three ;

[0047] Figure 13 Another optical waveguide topological structure provided by the embodiments of the present application Figure Five

[0048] Figure 14 Another structure of the beam splitter provided by the embodiments of the present application Figure Four ;

[0049] Figure 15 Another structure of the beam splitter provided by the embodiments of the present application Figure Five ;

[0050] Figure 16 Another structure of the beam splitter provided by the embodiments of the present application Figure Six ;

[0051] Figure 17 A comparison chart of different optimization methods of an optical waveguide provided by the embodiments of the present application;

[0052] Figure 18 A structural diagram of an optical module provided by the embodiments of the present application;

[0053] Figure 19 A structural diagram of an optical chip provided by the embodiments of the present application;

[0054] Figure 20 A structure of an electronic device provided by the embodiments of the present application Figure One ;

[0055] Figure 21 Another structure of an electronic device provided by the embodiments of the present application Figure Two ;

[0056] Figure 22 Another structure of an electronic device provided by the embodiments of the present application Figure Three . Detailed implementation manners

[0057] It should be noted that the terms "first", "second", etc. involved in the embodiments of the present application are only used for the purpose of distinguishing the same type of features, and cannot be understood as indicating relative importance, quantity, order, etc.

[0058] The terms "exemplary" or "for example" etc. involved in the embodiments of the present application are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, the use of the terms "exemplary" or "for example" etc. is intended to present the relevant concepts in a specific manner.

[0059] The terms "coupling" and "connection" involved in the embodiments of this application should be understood in a broad sense. For example, it can refer to a direct physical connection or an indirect connection implemented through electronic devices, such as a connection achieved through resistors, inductors, capacitors, or other electronic devices.

[0060] First, some basic concepts involved in the embodiments of this application are explained:

[0061] Adiabatic evolution theory: The adiabatic evolution of a mode means that in an optical waveguide that changes slowly with an extremely small step, the input mode also changes its mode field with an extremely small step and finally matches the output mode, completing a mode conversion without energy loss.

[0062] Inverse design: It is a product design method, corresponding to forward design. This inverse design method relies on intelligent algorithms and inputs the device parameters expected to be achieved, and inversely solves the structural composition of the device.

[0063] Optic power splitter (OPS): It is a device that divides one optical power equally or unequally into two or more optical powers on the optical path.

[0064] Mode division multiplexing (MDM): It refers to a technology in which multiple orthogonal modes with different paths and mode field distributions and carrying different information propagate together in the same multimode optical waveguide.

[0065] Polarization division multiplexing (PDM): Utilizing the polarization dimension of light, in the same wavelength channel, two independent data information are simultaneously transmitted through two mutually orthogonal polarization states of light to achieve the purpose of doubling the total system capacity and spectral utilization rate.

[0066] Optical phased arrays (OPA): It realizes the regulation of the propagation direction of the output light beam by controlling the phases of the light beams in each channel.

[0067] Silicon-on-insulator (SOI): That is, silicon on an insulating substrate. This technology introduces a buried oxide layer between the top silicon and the back substrate.

[0068] Particle swarm optimization (PSO): It is an evolutionary computing technology, originating from the study of the foraging behavior of bird flocks. The basic idea of the particle swarm optimization algorithm is to find the optimal solution through the cooperation and information sharing among individuals in the group.

[0069] Transverse electric (TE): It refers to an electromagnetic wave in which the electric field is perpendicular to the propagation direction and the magnetic field is along the propagation direction. Since the electric field and the magnetic field are perpendicular to each other on any cross-section perpendicular to the propagation direction, that is to say, their propagation path is perpendicular to the vibration direction.

[0070] Transverse magnetic (TM): It refers to an electromagnetic wave in which the magnetic field is perpendicular to the propagation direction and the electric field is along the propagation direction. Because on any cross-section perpendicular to the propagation direction, the electric field and the magnetic field are also perpendicular to each other.

[0071] Beam splitter: It refers to a device that splits a small number of optical signals (such as one beam) into multiple optical signals, or combines multiple optical signals into fewer optical signals. Among them, the beam splitter can be an optical power splitter or an optical demultiplexer, etc.

[0072] Optical power splitters play an important role in optical interconnection networks. They can control the transmission direction of optical signals between optical devices, the optical coupling between optical devices, and the distribution of optical power. Optical power splitters are applied in some small systems such as mode division multiplexing and polarization multiplexing. At the same time, in a complete optical interconnection network, a large number of optical power splitters are needed to maintain the normal operation of the optical network. In addition, in many practical application scenarios, such as optical phased arrays, the light source often needs to be divided into N parts (N>2).

[0073] To divide the light source into N parts (N>2), as Figure 1 shown, an embodiment of the present application provides a first type of power splitter. The first type of power splitter is based on a multimode interference (MMI) coupler. The basic principle of the MMI coupler is based on the self-imaging effect in a multimode waveguide. When a certain mode is input into the input waveguide, in the multimode waveguide, one or more replicated images of the input mode will be generated at periodic intervals along the propagation direction, which is the self-imaging of the multimode waveguide. This embodiment optimizes and designs a 1×2 type MMI, introduces a taper to reduce the transition loss between the MMI coupling region and the bus waveguide, and improves the device manufacturing tolerance, and cascades it on a silicon-on-insulator platform to obtain a 1×8 power splitter. However, this cascaded structure will increase the size of the device, and the loss and non-uniformity of the 1×2 power splitter will also be amplified with cascading, resulting in a very large loss and non-uniformity between channels for this cascaded structure. In terms of performance, the experimental results also show that the loss of the first type of power splitter is 6.7 dB and the non-uniformity is 1 dB at a wavelength of 1550 nm. In terms of integration, the length of the first type of power splitter is 2000 μm, and the integration is low.

[0074] In order to improve as Figure 1The integration and performance of the first type of power divider shown, in some possible implementation manners, such as shown, an embodiment of the present application provides a second type of power divider. Taking the second type of power divider as a 1×4 power divider as an example. First, through the guidance of the forward design formula, the coupling region size of a 1×4 type MMI is confirmed, and then the input and output waveguides of the MMI are optimized by using relevant segmentation and optimization methods in the simulated reverse design, and a four-way power divider is realized on the SOI platform. In terms of performance, the experimental results show that the loss of this device is lower than 0.62 dB in the wavelength band of 1520 - 1624 nm, and the non-uniformity is 0.89 dB. In terms of integration, the device length is 36 μm. However, the main body of the second type of power divider provided in this embodiment still belongs to the forward design guided by the formula, and it cannot give full play to the advantages of high flexibility and compact size of the reverse design. Secondly, the adopted segmentation and optimization method has a poor convergence effect, and if there is a topological structure satisfying w i > w i+1 < w i+2 in the optimized structural parameters, then on the SOI platform, a sharp corner structure (also called an acute angle structure) as shown in Figure 2 will be generated. This sharp corner structure is difficult to realize in the manufacturing process, and there will be a large manufacturing error, which is difficult to meet the design requirements for the performance of the optical waveguide.

[0075] In some possible implementation manners, such as Figure 3 shown, an embodiment of the present application provides a third type of power divider. Taking the third type of power divider as a 1×4 power divider as an example. The third type of power divider realizes a four-way power divider on the SOI platform by using the adiabatic evolution theory. The working principle of this third type of power divider is based on the mode evolution between the fundamental mode of the input waveguide and the supermodes of the four output waveguides. As the width of the input waveguide decreases, most of the light is compressed into the waveguide cladding. By designing the positions and directions of the four tapered waveguides, the energy in the cladding will gradually leak out due to the gradual narrowing of the input waveguide width, and the leaked waveguide is controlled to be converted into the output waveguide. In terms of performance, the experimental results show that the loss of this device is lower than 0.4 dB in the wavelength band of 1480 - 1580 nm, and the non-uniformity is 0.68 dB. In terms of integration, the device length is 12.5 μm. However, the platform of this scheme is based on a 340 nm SOI platform, which belongs to an unconventional process platform, so the process is relatively complex.

[0076] In some possible implementation manners, such as Figure 4As shown in the figure, an embodiment of the present application provides a fourth type of power splitter. The fourth type of power splitter uses an analog reverse design method to design a two-way power splitter. The area to be optimized is divided into several trapezoidal waveguide structures with equal height h, and the upper and lower bases w of the trapezoids in the trapezoidal waveguide structures are used as variables to be optimized by the particle swarm algorithm. In terms of performance, the experimental results show that the loss of the device is lower than 0.3 dB in the 1500 - 1580 nm band. In terms of integration, the device length is 2 μm. However, this method is only applicable to the production of two-way power splitters. When the number of channels is greater than two, not only the loss needs to be considered, but also the consistency between channels needs to be considered, and the effect of the adopted segmentation and optimization method is poor. Moreover, the platform of this solution is based on a 248 nm SOI platform, which is an unconventional process platform, so the process is relatively complex.

[0077] In summary, as Figure 5 shown, the first type of power splitter has low integration, large loss, and poor uniformity between channels. Although as Figure 1 shown, the second type of power splitter, as Figure 2 shown, the third type of power splitter, and as Figure 4 shown, the fourth type of power splitter have improved and enhanced in terms of performance and integration compared to the first type of power splitter as Figure 5 shown, the required preparation process is complex, which increases the difficulty of process preparation, and the single dimension of the optical waveguide structure is not conducive to the search of the algorithm.

[0078] In order to reduce the difficulty of process preparation of the optical waveguide, improve the process tolerance of the optical waveguide and the algorithm search space. As Figure 1 shown, an embodiment of the present application provides a beam splitter 1000. The beam splitter 1000 can be an optical power splitter or a wavelength division multiplexer. The beam splitter 1000 includes a multiplexing end 100, a tapered waveguide structure 200, and a plurality of demultiplexing ends 300. The tapered waveguide structure 200 includes at least two trapezoidal waveguide structures A and at least one rectangular waveguide structure B. Among them: at least two trapezoidal waveguide structures A are cascaded, and for two adjacent trapezoidal waveguide structures A among the at least two trapezoidal waveguide structures A, coupling between the two adjacent trapezoidal waveguide structures A is achieved based on one rectangular waveguide structure B among the at least one rectangular waveguide structure B. The multiplexing end 100 is coupled to the first trapezoidal waveguide structure A in the cascaded at least two trapezoidal waveguide structures A, and the plurality of demultiplexing ends 300 are coupled to the last trapezoidal waveguide structure A in the cascaded at least two trapezoidal waveguide structures A.

[0079] In the embodiments of the present application, for two adjacent trapezoidal waveguide structures among at least two trapezoidal waveguide structures in the beam splitter, by inserting a section of rectangular waveguide structure between the two adjacent trapezoidal waveguide structures, the coupling of the two adjacent trapezoidal waveguide structures is realized. The introduction of the rectangular waveguide structure avoids the sharp corner structure that may be generated in the method of directly coupling two adjacent trapezoidal waveguide structures, optimizes the difficulty in the segmentation method of the tapered waveguide structure, and improves the process tolerance of the prepared tapered waveguide structure. At the same time, the introduction of the rectangular waveguide structure also increases the variable dimension, thereby expanding the algorithm search space, better exerting the global search ability of the optimization algorithm, and further improving the performance of the beam splitter.

[0080] To keep the concepts involved in the listed embodiments consistent, the following definitions are made: Both the trapezoidal waveguide structure A and the rectangular waveguide structure B are three-dimensional structures. The trapezoid in the trapezoidal waveguide structure A includes an upper base and a lower base, and the size of the upper base of the trapezoid is smaller than the size of the lower base of the trapezoid. The height of the trapezoidal waveguide structure A refers to the distance between the upper base and the lower base of the trapezoid. The length of the rectangular waveguide structure B refers to the size of the edge along the light beam transmission direction.

[0081] In one example, for two adjacent cascaded trapezoidal waveguide structures A, as Figure 6 shown in (a), the upper base of the front-stage trapezoidal waveguide structure A is coupled to the lower base of the rear-stage trapezoidal waveguide structure A through the rectangular waveguide structure B.

[0082] In one example, for two adjacent cascaded trapezoidal waveguide structures A, as Figure 7 shown in (b), the upper base of the front-stage trapezoidal waveguide structure A is coupled to the upper base of the rear-stage trapezoidal waveguide structure A through the rectangular waveguide structure B.

[0083] In one example, for two adjacent cascaded trapezoidal waveguide structures A, as Figure 7 shown in (c), the lower base of the front-stage trapezoidal waveguide structure A is coupled to the upper base of the rear-stage trapezoidal waveguide structure A through the rectangular waveguide structure B.

[0084] In one example, for two adjacent cascaded trapezoidal waveguide structures A, as Figure 7 shown in (d), the lower base of the front-stage trapezoidal waveguide structure A is coupled to the lower base of the rear-stage trapezoidal waveguide structure A through the rectangular waveguide structure B.

[0085] In some possible implementation manners, the beam splitter 1000 is configured to divide the optical wave input from the multiplexing end 100 into multiple paths and output them respectively from the corresponding multiple demultiplexing ends 300. Or the beam splitter 1000 is configured to couple multiple optical waves input from the multiple demultiplexing ends 300 into one path and output it from the multiplexing end 100.

[0086] In some possible embodiments, the number of trapezoidal waveguide structures A in the tapered waveguide structure 200 is 1 more than the number of rectangular waveguide structures B. For example, trapezoidal waveguide structures A are provided at both ends of the tapered waveguide structure 200, and are coupled to the combining end 100 and the splitting end 300 based on the trapezoidal waveguide structures A. Alternatively, the number of rectangular waveguide structures B is 1 more than the number of trapezoidal waveguide structures A in the tapered waveguide structure 200. For example, rectangular waveguide structures B are provided at both ends of the tapered waveguide structure 200, and are coupled to the combining end 100 and the splitting end 300 based on the rectangular waveguide structures B.

[0087] In some possible embodiments, the rectangular waveguide structure B in the tapered waveguide structure 200 is a sub-wavelength structure. Such as a rectangular sub-wavelength transition waveguide. The sharp corner structures that may be generated in the process preparation of the rectangular waveguide structure B greatly reduce the process preparation difficulty.

[0088] In some possible embodiments, the trapezoidal waveguide structure A can be an ordinary trapezoidal (non-isosceles trapezoidal and non-right trapezoidal) waveguide structure or an isosceles trapezoidal waveguide structure A or a right trapezoidal waveguide structure A.

[0089] In some examples, when the trapezoidal waveguide structure A is an ordinary trapezoidal waveguide structure A. Such as Figure 7 As shown, the tapered waveguide structure 200 includes n ordinary trapezoidal waveguide structures A and n - 1 rectangular waveguide structures B. From the congruent properties of the ordinary trapezoid, it can be known that after determining the sizes of the upper and lower bases of the ordinary trapezoid in the ordinary trapezoidal waveguide structure A in this embodiment, the ordinary trapezoidal waveguide structure A cannot be uniquely determined, and thus the tapered waveguide structure 200 cannot be uniquely determined either. Therefore, in order to uniquely determine the shape structure of the tapered waveguide structure 200 in this embodiment, the base of the ordinary trapezoidal waveguide structure A is divided into two parts for separate determination. As Figure 8 shown by the black dashed line in, the upper and lower bases of the ordinary trapezoidal waveguide structure A are respectively divided into two parts, and by optimizing the two parts of the same base respectively, the ordinary trapezoidal waveguide structure A is uniquely determined, thereby determining the tapered waveguide structure 200. So as Figure 8 shown, the n ordinary trapezoidal waveguide structures A include width variables such as w1, w2, w3,..., w 2n and height variables such as h1, h2, h3,..., h n The n - 1 rectangular waveguide structures B include length variables such as l1, l2, l3,..., l n-1 and the length of the rectangular waveguide structure B is greater than 0.

[0090] Exemplarily, for two adjacent trapezoidal waveguide structures A in cascade, the width of the base of the front-stage trapezoidal waveguide structure A coupled to the rectangular waveguide structure B is equal to the width of the rectangular waveguide structure B, and the width of the base of the rear-stage trapezoidal waveguide structure A coupled to the rectangular waveguide structure B is equal to the width of the rectangular waveguide structure B.

[0091] Exemplarily, as Figure 8 shown, a beam splitter 1000 includes a multiplexing end 100, a tapered waveguide structure 200 as Figure 9 shown, and M splitting ends 300. The spacing variables between two adjacent splitting ends 300 among the M splitting ends 300 include y1, y2, …, y M-1 .

[0092] In some examples, this embodiment provides an optimization algorithm (such as a genetic algorithm, a particle swarm optimization algorithm, etc.) for iteratively calculating the structural parameters of the beam splitter 1000. Then, based on the verification conditions, the calculation results of the iterative calculation are verified to determine the structural parameters to be optimized in the beam splitter 1000 from the calculation results. The structural parameters include at least one of the following: the upper base length of the trapezoidal waveguide structure A, the lower base length of the trapezoidal waveguide structure A, the height of the trapezoidal waveguide structure A, the length of the rectangular waveguide structure B, the width of the rectangular waveguide structure B, the height of the rectangular waveguide structure B, and the number of splitting ends 300.

[0093] Exemplarily, as Figure 8 shown, taking the particle swarm optimization algorithm as an example, the structural parameters to be optimized in the beam splitter 1000 are optimized. Specifically, it includes steps S100 - S500:

[0094] S100. Determine the range of variables to be optimized and generate a preset number of particles according to the range of variables to be optimized.

[0095] Specifically, in this embodiment, the variables to be optimized include the width variable w and height variable h of the ordinary trapezoidal waveguide structure A, the length variable l of the rectangular waveguide structure B, and the spacing variable y between two adjacent splitting ends 300. The range of the variables to be optimized can be determined according to the actual design requirements and is not limited here. For example, if the rectangular waveguide structure B adopts a sub - wavelength structure, the range of the length variable l of the rectangular waveguide structure B needs to be less than the wavelength of the light beam to be split.

[0096] Specifically, a preset number of particles are randomly generated within the range of variables to be optimized. For example, 90 particles (i.e., 90 different initial values of variables) are generated. The specific number of generated particles can be determined according to the actual design requirements and is not limited here.

[0097] S200. Construct the initial position variables and initial velocity variables of the particles.

[0098] Specifically:

[0099] The expression of the initial position variables is:

[0100] X i =[x1,x2,x3,…,x n ​

[0101] The expression of the initial velocity variable is:

[0102] V i = [v1, v2, v3, …, v n

[0103] where X i represents the initial position variable of the i-th particle, and i represents the particle sequence number. x n represents the structural parameter. n = 1, 2, …, N, where N represents the number of independent variables and n represents the independent variable sequence number. V i represents the initial velocity variable of the i-th particle. v n represents the velocity of the change of x n .

[0104] Specifically, taking the beam splitter 1000 shown in Figure 10 as an example, then:

[0105] The expression of the initial position variable is:

[0106] X i = [w1, w2, …, w 2n , h1, h2, …, h n , l1, l2, …, l n-1 , y1, y2, …, y M-1

[0107] The expression of the initial velocity variable is:

[0108]

[0109] where X i represents the initial position variable of the i-th particle, and i represents the particle sequence number. w1, w2, …, w 2n represent the ordinary trapezoidal waveguide width variables. h1, h2, …, h n represent the ordinary trapezoidal waveguide height variables. l1, l2, …, l n-1 represent the rectangular waveguide structure B length variables. y1, y2, …, y M-1 represent the spacing variables between two adjacent splitting ends 300. V i represents the initial velocity variable of the i-th particle. represents the initial velocity variable corresponding to the ordinary trapezoidal waveguide width variable. represents the initial velocity variable corresponding to the ordinary trapezoidal waveguide height variable. represents the initial velocity variable corresponding to the rectangular waveguide structure B length variable. ​​Represents the initial velocity variable corresponding to the spacing variable between two adjacent splitting ends 300. By setting the width w and height h of the trapezoidal waveguide structure A, the length l of the rectangular waveguide structure B, and the spacing y between two adjacent splitting ends 300 as optimization variables, the particle swarm algorithm is used for optimization, the search area and search dimension of the algorithm are increased, a better convergence effect is obtained, the designed device has a better effect and a more compact size.

[0110] S300. According to the initial position variable, the initial velocity variable, and the iterative update relation formula of the particle swarm optimization algorithm, the updated position variable and the updated velocity variable are obtained.

[0111] Specifically:

[0112] The expression of the updated position variable is:

[0113]

[0114] The expression of the updated velocity variable is:

[0115]

[0116] where d = 1, 2, 3, …, K, K represents the number of iterations, and d represents the iteration number. V i d Represents the velocity variable of the i-th particle after the d-th iterative update. Represents the position variable of the i-th particle after the d-th iterative update. w, c1, r1, c2, and r2 represent coefficients. Represents the historical optimal position searched by the i-th particle after the d-th iteration (i.e., the optimal solution verified by the i-th particle in the current iteration round). g best d represents the historical optimal position of the population in the d-th iteration (i.e., the optimal solution verified among all particles in the current iteration round).

[0117] Furthermore, r1 and r2 can be set to the default value 2, w can take the system default value 0.9, c1 and c2 can be random numbers uniformly distributed between 0 and 1, K is the number of iterations, and K = 150 can be taken.

[0118] S400. According to the position variable and the velocity variable, the output result of the beam splitter is obtained.

[0119] S500. Based on the verification condition, the output result is verified to determine the structural parameters of the beam splitter from the output result.

[0120] Specifically, the calculation results of the iterative calculation are verified based on the following verification formula, and particles with a better FOM are continuously searched until the iteration ends (i.e., after K rounds of iteration), and the structural parameters corresponding to the globally optimal particle in the calculation results that satisfy the verification formula are used as the determined structural parameters, that is, the structural parameters of the beam splitter are determined, thereby obtaining the final optimization result. The expression of the verification formula is as follows:

[0121]

[0122] where FOM represents the verification formula, M represents the number of splitting ends 300, T represents the number of optical wave wavelengths, and P m (λ t ) is the actual output power of the m-th splitting end 300 at the t-th wavelength. P m represents the target output power of the m-th splitting end 300.

[0123] Furthermore, the calculation results of the beam splitter 1000 can be normalized, that is:

[0124]

[0125] Furthermore, the total number of channels (i.e., the number of splitting ends 300) is M, T wavelengths are evenly taken in the target wavelength band, the spacing between adjacent wavelengths is equal, the power of each port at each wavelength is measured, and the waveguide widths of the input end and the output end are fixed at 0.5 μm. The variable y is used to control the gap between adjacent splitting ends 300. In addition, the height of the waveguide (not limited to the 220 nm SOI process platform) and the refractive index of the core-cladding layer (not limited to the SOI platform) can both be used as variables to be added to the algorithm for optimization. Among them, the material platform is not limited to the SOI platform, and can also be silica, polymer, etc., to increase the flexibility and expandability of the design. P m (λ t ) has a target value of P m , so the smaller the FOM value is, the better in subsequent optimization. The width variable w and height variable h of the trapezoidal waveguide structure A, the length variable l of the rectangular waveguide structure B, and the spacing variable y between two adjacent splitting ends 300 are used as variables to reduce the FOM through the particle swarm algorithm, thereby optimizing the beam splitter. Through the method provided in this embodiment, a beam splitter with a large bandwidth and good performance can be optimized to achieve the function of splitting the input light and outputting it from the splitting end 300, but only supports the TE fundamental mode.

[0126] To enable the beam splitter 1000 to achieve the function of multiplexing splitting for different modes and different polarizations. In some possible implementation manners, such as Figure 9Take the beam splitter 1000 shown as an example. To enable the beam splitter 1000 to support the function of splitting two different modes / polarizations simultaneously, the modes (polarizations) at its input end and the corresponding FOM are shown in Table 1. This embodiment can achieve the function of splitting the input light and outputting it from the splitting end 300, and supports TE and TM modes of any order. By editing the FOM, a beam splitter 1000 with any mode, any polarization, and any number of channels can be realized, increasing the flexibility and expandability of the design of the beam splitter 1000.

[0127] Table 1

[0128]

[0129] In some examples, when the trapezoidal waveguide structure A is an isosceles trapezoidal waveguide structure A. As Figure 9 shown, the tapered waveguide structure 200 includes n isosceles trapezoidal waveguide structures A and n - 1 rectangular waveguide structures B. From the congruent properties of the isosceles trapezoid, it can be known that after determining the sizes of the upper and lower bases of the isosceles trapezoid in the isosceles trapezoidal waveguide structure A in this embodiment, the isosceles trapezoidal waveguide structure A is also uniquely determined, and thus the tapered waveguide structure 200 can also be uniquely determined. So as Figure 11 shown, the n isosceles trapezoidal waveguide structures A include width variables such as w1, w2, w3, …, w n and height variables such as h1, h2, h3, …, h n The n - 1 rectangular waveguide structures B include length variables such as l1, l2, l3, …, l n-1 For two adjacent cascaded trapezoidal waveguide structures A, the width of the bottom of the previous trapezoidal waveguide structure A coupled to the rectangular waveguide structure B is equal to the width of the rectangular waveguide structure B, and the width of the bottom of the subsequent trapezoidal waveguide structure A coupled to the rectangular waveguide structure B is equal to the width of the rectangular waveguide structure B.

[0130] In some examples, as Figure 11 shown, a beam splitter 1000 includes a multiplexing end 100, a tapered waveguide structure 200 as Figure 12 shown, and M splitting ends 300. The spacing variables between two adjacent splitting ends 300 among the M splitting ends 300 include y1, y2, …, y M-1 .

[0131] In some examples, this embodiment provides an optimization algorithm (such as a genetic algorithm, a particle swarm optimization algorithm, etc.) for iteratively calculating the structural parameters of the beam splitter 1000, and verifying the calculation results of the iterative calculation based on a verification condition, so as to determine the structural parameters to be optimized in the beam splitter 1000 from the calculation results. The structural parameters include at least one of the following: the upper base length of the trapezoidal waveguide structure A, the lower base length of the trapezoidal waveguide structure A, the height of the trapezoidal waveguide structure A, the length of the rectangular waveguide structure B, the width of the rectangular waveguide structure B, the height of the rectangular waveguide structure B, and the number of splitting ends 300.

[0132] Exemplarily, taking the particle swarm optimization algorithm as an example, the structural parameters to be optimized in the beam splitter 1000 are optimized. The optimization process in this embodiment is similar to Figure 11 the steps S100 - S500 shown. Due to the difference in the trapezoidal waveguide structure A, the specific optimization process is different in steps S200 and S500. As follows:

[0133] S100. Determine the range of variables to be optimized and generate a preset number of particles according to the range of variables to be optimized.

[0134] Specifically, in this embodiment, the variables to be optimized include the width variable w and height variable h of the ordinary trapezoidal waveguide structure A, the length variable l of the rectangular waveguide structure B, and the spacing variable y between two adjacent splitting ends 300. The range of variables to be optimized can be determined according to actual design requirements and is not limited here. For example, if the rectangular waveguide structure B adopts a sub - wavelength structure, the range of the length variable l of the rectangular waveguide structure B needs to be less than the wavelength of the light beam to be split.

[0135] Specifically, randomly generate a preset number of particles within the range of variables to be optimized. For example, generate 90 particles (i.e., 90 different initial values of variables). The specific number of generated particles can be determined according to actual design requirements and is not limited here.

[0136] S200. Construct the initial position variables and initial velocity variables of the particles.

[0137] Specifically:

[0138] The expression of the initial position variables is:

[0139] X i =[x1,x2,x3,…,x n

[0140] The expression of the initial velocity variables is:

[0141] V i =[v1,v2,v3,…,v n

[0142] ​​Among them, X i represents the initial position variable of the i-th particle, and i represents the particle serial number. x n represents the structural parameter. n = 1, 2, …, N, where N represents the number of independent variables and n represents the independent variable serial number. V i represents the initial velocity variable of the i-th particle. v n represents the velocity of the change of x n

[0143] Specifically, taking the beam splitter 1000 shown in Figure 10 as an example, then:

[0144] The expression of the initial position variable is:

[0145] X i = [w1, w2, …, w n , h1, h2, …, h n , l1, l2, …, l n-1 , y1, y2, …, y M-1

[0146] The expression of the initial velocity variable is:

[0147]

[0148] Among them, X i represents the initial position variable of the i-th particle, and i represents the particle serial number. w1, w2, …, w n represent the isosceles trapezoidal waveguide width variables. h1, h2, …, h n represent the isosceles trapezoidal waveguide height variables. l1, l2, …, l n-1 represent the rectangular waveguide structure B length variables. y1, y2, …, y M-1 represent the spacing variables between two adjacent splitting ends 300. V i represents the initial velocity variable of the i-th particle. represents the initial velocity variable corresponding to the isosceles trapezoidal waveguide width variable. represents the initial velocity variable corresponding to the isosceles trapezoidal waveguide height variable. represents the initial velocity variable corresponding to the rectangular waveguide structure B length variable. represents the initial velocity variable corresponding to the spacing variable between two adjacent splitting ends 300.

[0149] S300. According to the iterative update relationship of the initial position variable, the initial velocity variable and the particle swarm optimization algorithm, the updated position variable and the updated velocity variable are obtained.

[0150] Specifically:

[0151] ​​The expression for the updated position variable is:

[0152]

[0153] The expression for the updated velocity variable is:

[0154]

[0155] where d = 1, 2, 3, …, K, K represents the number of iterations, and d represents the iteration sequence number. V i d represents the velocity variable of the i-th particle after the d-th iteration update. represents the position variable of the i-th particle after the d-th iteration update. w, c1, r1, c2, and r2 represent coefficients. represents the historical optimal position searched by the i-th particle after the d-th iteration (i.e., the optimal solution verified by the i-th particle in the current iteration round). g best d represents the historical optimal position of the population in the d-th iteration (i.e., the optimal solution verified by all particles in the current iteration round).

[0156] Furthermore, r1 and r2 can be set to the default value 2, w can take the system default value 0.9, c1 and c2 can be random numbers uniformly distributed between 0 and 1, K is the number of iterations, and K can take K = 150.

[0157] S400. Obtain the output result of the beam splitter according to the position variable and the velocity variable.

[0158] S500. Verify the output result based on the verification condition to determine the structural parameters of the beam splitter from the output result.

[0159] Specifically, verify the calculation result of the iterative calculation based on the following verification formula, continuously search for particles with a better FOM until the iteration ends (i.e., after completing K rounds of iteration), and use the structural parameters corresponding to the global optimal particle in the calculation result that satisfies the verification formula as the determined structural parameters, that is, the structural parameters of the beam splitter are determined, thereby obtaining the final optimization result. The expression of the verification formula is as follows:

[0160]

[0161] where FOM represents the verification formula, M represents the number of splitting ends 300, T represents the number of optical wave wavelengths, P m (λ t ) is the actual output power of the m-th splitting end 300 at the t-th wavelength. P m represents the target output power of the m-th splitting end 300.

[0162] Furthermore, the calculation result of the beam splitter 1000 can be normalized, i.e.:

[0163]

[0164] Furthermore, the beam splitter 1000 can be an M-way equal-power splitter. Then:

[0165]

[0166] Furthermore, the total number of channels (i.e., the number of splitting ends 300) is M. T wavelengths are evenly taken in the target wavelength band, and the spacing between adjacent wavelengths is equal. The power of each port at each wavelength is measured, and the waveguide widths of the input end and the output end are fixed at 0.5 μm. Due to the symmetry of the tapered waveguide structure 200 in the beam splitter 1000, only the transmittance of the upper half M / 2 splitting ends 300 needs to be considered during calculation. The variable y is used to control the gap between adjacent splitting ends 300. In addition, the height of the waveguide (not limited to the 220 nm SOI process platform) and the refractive index of the core-cladding layer (not limited to the SOI platform) can both be used as variables to be added to the algorithm for optimization. P m (λ t ) has a target value of P m , so the smaller the FOM value is during subsequent optimization, the better. The width variable w and height variable h of the trapezoidal waveguide structure A, the length variable l of the rectangular waveguide structure B, and the spacing variable y between two adjacent splitting ends 300 are used as variables to reduce the FOM through the particle swarm algorithm, thereby optimizing the beam splitter 1000. This embodiment can achieve the function of splitting the input light and outputting it from the splitting ends 300, but only supports the transverse electric fundamental mode.

[0167] To enable the beam splitter 1000 to achieve the function of multi-way beam splitting supporting different modes and different polarizations. In some possible implementation manners, taking the beam splitter 1000 as shown in Figure 12 as an example. To enable this beam splitter 1000 to support the function of splitting two different modes / polarizations simultaneously, the mode (polarization) at its input end and the corresponding FOM are shown in Table 2. This embodiment can achieve the function of splitting the input light and outputting it from the splitting ends 300, and supports any-order TE and TM modes.

[0168] Table 2

[0169]

[0170] In some possible implementation manners, taking the beam splitter 1000 as shown in Figure 12 as an M-way equal-power splitter as an example. To enable this beam splitter 1000 to support the function of splitting two different modes / polarizations simultaneously, the mode (polarization) at its input end and the corresponding FOM are shown in Table 3.

[0171] Table 3

[0172]

[0173] In some examples, when the trapezoidal waveguide structure A is a right-angled trapezoidal waveguide structure A. As Figure 12 shown, the tapered waveguide structure 200 includes n right-angled trapezoidal waveguide structures A and n - 1 rectangular waveguide structures B. From the congruence property of right-angled trapezoids, after determining the sizes of the upper and lower bases of the right-angled trapezoid in the right-angled trapezoidal waveguide structure A in this embodiment, the right-angled trapezoidal waveguide structure A is also uniquely determined, and thus the tapered waveguide structure 200 can also be uniquely determined. So as Figure 13 shown, the n right-angled trapezoidal waveguide structures A include width variables such as w1, w2, w3,..., w n and height variables such as h1, h2, h3,..., h n The n - 1 rectangular waveguide structures B include length variables such as l1, l2, l3,..., l n-1

[0174] Exemplarily, as Figure 13 shown, a beam splitter 1000 includes a combiner end 100, multiple tapered waveguide structures 200 as Figure 14 shown, and M splitter ends 300. The beam splitter 1000 couples M - 1 tapered waveguide structures 200 to be optimized on a main single-mode waveguide, where the tapered waveguide structure 200 is a branch single-mode output waveguide. Optimize the M - 1 branch single-mode waveguides so that the energy in each branch output waveguide is controlled to the target power P m , and an M-way single-mode arbitrary ratio power divider can be realized. To ensure that the distance between the single-mode waveguide to be optimized and the main single-mode waveguide is equal, during optimization, the tapered waveguide structure 200 is divided into several segments of right-angled trapezoidal waveguide structures A, and a section of rectangular waveguide structure B (such as a rectangular sub-wavelength transition waveguide) is inserted between every two right-angled trapezoidal waveguide structures A. Fix the width W of the input single-mode waveguide and the distance d between the input and output waveguides. Regard the width variable w and height variable h of the right-angled trapezoidal waveguide structure A and the length variable l of the rectangular waveguide structure B as variables for optimization. Monitor the energy in the required wavelength band at the output end of the branch single-mode waveguide Define the verification formula expression as follows:

[0175]

[0176] P m is the target output power of each waveguide to be optimized, based on as Figure 13 ​Optimization algorithms similar to the optimized process shown (such as the particle swarm optimization algorithm) are used to optimize the single-mode waveguides of M - 1 branches, and design a single-mode waveguide for the branch with the actual output power being the target output power. Thus, the optimized design of the beam splitter 1000 of this structure can be achieved. This embodiment can achieve the function of splitting the input optical power into M beams in any ratio and outputting from M output waveguides, and only supports the TE0 mode.

[0177] Specifically, when M = 4, that is, when the beam splitter 1000 couples three gradually changing waveguide structures 200 with different structures to be optimized (such as Figure 10 coupler 1, coupler 2, and coupler 3 in Figure 15 on a main single-mode waveguide). As shown in the beam splitter in

[0178] P m is the target output power of each waveguide to be optimized. Based on an optimization algorithm similar to the optimization process shown in Figure 15 such as the particle swarm optimization algorithm, the three single-mode waveguides of the branches are optimized to design three single-mode waveguides (also called couplers) with output powers of P1, P2, and P3 respectively. Thus, the optimized design of the beam splitter 1000 of this structure can be achieved. This embodiment can achieve the function of splitting the input optical power into 4 beams in any ratio and outputting from 4 output waveguides, and only supports TE0.

[0179] Exemplarily, when the beam splitter 1000 couples M - 1 gradually changing waveguide structures 200 with the same structure to be optimized on a main single-mode waveguide, the verification formula expression is defined as follows:

[0180]

[0181] Furthermore, when M = 4, that is, when the beam splitter 1000 couples three gradually changing waveguide structures 200 with the same structure to be optimized on a main single-mode waveguide. As shown in the beam splitter 1000 in Figure 10 is a four-way equal-power beam splitter of the directional coupler type designed based on the particle swarm optimization algorithm. This structure serially connects three single-mode output waveguides with the same structure to be optimized on a main single-mode waveguide. By optimizing three completely identical single-mode waveguides of the branches to control the energy in each branch output waveguide to be 1 / 4 of the input energy, a four-way single-mode beam splitter can be achieved. The verification formula expression is defined as follows:

[0182]

[0183] Since The normalized value of the target output power is 1 / 4. Therefore, the smaller the FOM, the better during optimization. This embodiment can achieve the function of equally dividing the input optical power into four parts and outputting from four output waveguides, and only supports TE0.

[0184] In some possible implementation manners, such as Figure 16 shown, it is a relationship curve graph of the FOM value and the number of iterations provided by this embodiment. Among them, the solid curve represents the relationship curve graph of the FOM value and the number of iterations obtained by using the optical waveguide optimization method (improved method) provided by this application embodiment. The dashed curve represents the relationship curve graph of the FOM value and the number of iterations obtained by using the related optical waveguide structure optimization method (traditional method). From Figure 17 it can be seen that the optical waveguide optimization method provided by this application has better convergence ability.

[0185] In some possible implementation manners, based on the optimization design method of the beam splitter 1000 in this embodiment, the design of optical devices such as power splitters, directional couplers, and asymmetric Y-branches can be realized.

[0186] This application embodiment also provides an optical module, such as Figure 17 shown, the optical module 10000 includes a beam splitter 1000 and a mounting substrate 2000. The beam splitter 1000 is disposed on the mounting substrate 2000. The beam splitter 1000 includes a multiplexing end 100, a tapered waveguide structure 200, and a plurality of demultiplexing ends 300. The tapered waveguide structure 200 includes at least two trapezoidal waveguide structures A and at least one rectangular waveguide structure B. Wherein: at least two trapezoidal waveguide structures A are cascaded, and for two adjacent trapezoidal waveguide structures A among the at least two trapezoidal waveguide structures A, coupling is realized between the two adjacent trapezoidal waveguide structures A based on one rectangular waveguide structure B among the at least one rectangular waveguide structure B. The multiplexing end 100 is coupled to the first trapezoidal waveguide structure A among the at least two cascaded trapezoidal waveguide structures A, and the plurality of demultiplexing ends 300 are coupled to the last trapezoidal waveguide structure A among the at least two cascaded trapezoidal waveguide structures A.

[0187] This application embodiment also provides an optical chip, such as Figure 18 shown, the optical chip 20000 includes a beam splitter 1000 and a mounting substrate 2000. The beam splitter 1000 is disposed on the mounting substrate 2000.

[0188] This application embodiment provides an electronic device, such as Figure 19 shown, the electronic device 100000 includes a controller 30000 and an optical module 10000. Or as Figure 20As shown, the electronic device 100000 includes a controller 30000 and an optical chip 20000.

[0189] In some possible implementation manners, the electronic device 100000 is an optical phased array. As Figure 21 shown, the input light enters an optical waveguide array (such as the curved waveguide shown in Figure 22 ) through a beam splitter. The optical waveguide array is composed of a plurality of waveguides, and each waveguide can serve as a phased array element and is composed of an optical waveguide core layer and an electrode layer. By setting different voltages (also referred to as drive signals) on different voltage levels through the controller 30000 (such as a voltage control system), different additional refractive indexes exist on different core layers, and there will be a certain phase difference in the light beam on the output cross-section. Under the action of the phase difference, the deflection of the light beam is realized, achieving the effect of far-field light beam scanning. The beam splitter of this design first has a compact size, increasing the integration degree of the optical phased array. Secondly, the low loss and good consistency of the beam splitter improve the quality of the output light spot.

[0190] The embodiment of the present application provides a beam splitter, an optical module, an optical chip and an electronic device. For two adjacent trapezoidal waveguide structures among at least two trapezoidal waveguide structures in the beam splitter, by inserting a section of rectangular waveguide structure between the two adjacent trapezoidal waveguide structures, the coupling of the two adjacent trapezoidal waveguide structures is realized. The introduction of the rectangular waveguide structure avoids the sharp corner structure that may be generated in the method of directly coupling two adjacent trapezoidal waveguide structures, optimizes the difficulty in the segmentation method of the tapered waveguide structure, and improves the process tolerance of the prepared tapered waveguide structure. At the same time, the introduction of the rectangular waveguide structure also increases the variable dimension, thereby increasing the algorithm search space, better exerting the global search ability of the optimization algorithm, and further improving the performance of the beam splitter. Compared with the first type of power splitter shown in Figure 22 , the beam splitter designed by the solution provided in this embodiment is not in a cascaded form, so it is more compact in size. Compared with the third type of power splitter shown in Figure 1 , the beam splitter designed by the solution provided in this embodiment is compatible with the 220nm platform of SOI and is more convenient in process manufacturing. Compared with the second type of power splitter shown in Figure 4 and the fourth type of power splitter shown in Figure 2 Figure 5 , the beam splitter designed by the solution provided in this embodiment avoids the sharp corner structure that may be generated in the process preparation. Therefore, through the above implementation manners, the purpose of preparing a beam splitter with low loss, good consistency, high uniformity, compact size (i.e., high integration degree), large process tolerance, excellent bandwidth and compatible with the 220nm SOI platform is achieved.

[0191] The processor involved in the embodiments of the present application may be a chip. For example, it may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0192] The memory involved in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0193] It should be understood that in various embodiments of the present application, the sequence numbers of the above processes do not imply the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0194] Those of ordinary skill in the art can realize that the modules and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present application.

[0195] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and modules described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0196] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division, and there can be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of devices or modules can be in electrical, mechanical, or other forms.

[0197] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they can be located in one device, or distributed to multiple devices. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0198] In addition, the functional modules in each embodiment of the present application can be integrated in one device, or each module can exist physically alone, or two or more modules can be integrated in one device.

[0199] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more media integrated therein. The available medium may be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)), etc.

[0200] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of changes or substitutions, which should all be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A beam splitter, characterized in that, It includes a combining end, a tapered waveguide structure, and multiple splitting ends; the tapered waveguide structure includes at least two trapezoidal waveguide structures and at least one rectangular waveguide structure; where: The at least two trapezoidal waveguide structures are cascaded, and for two adjacent trapezoidal waveguide structures among the at least two trapezoidal waveguide structures, the two adjacent trapezoidal waveguide structures are coupled based on one rectangular waveguide structure B among the at least one rectangular waveguide structure; The combining end is coupled to the first trapezoidal waveguide structure among the at least two cascaded trapezoidal waveguide structures, and the multiple splitting ends are coupled to the last trapezoidal waveguide structure among the at least two cascaded trapezoidal waveguide structures.

2. The beam splitter according to claim 1, wherein, For two adjacent trapezoidal waveguide structures in cascade, any of the following coupling methods is satisfied: The upper base of the previous-stage trapezoidal waveguide structure is coupled to the lower base of the subsequent-stage trapezoidal waveguide structure through the rectangular waveguide structure; Or, the upper base of the previous-stage trapezoidal waveguide structure is coupled to the upper base of the subsequent-stage trapezoidal waveguide structure through the rectangular waveguide structure; Or, the lower base of the previous-stage trapezoidal waveguide structure is coupled to the upper base of the subsequent-stage trapezoidal waveguide structure through the rectangular waveguide structure; Or, the lower base of the previous-stage trapezoidal waveguide structure is coupled to the lower base of the subsequent-stage trapezoidal waveguide structure through the rectangular waveguide structure.

3. The beam splitter according to claim 1 or 2, characterized in that, Iterative calculations are performed on the structural parameters of the beam splitter, and the calculation results of the iterative calculations are verified based on verification conditions to determine the structural parameters from the calculation results; the structural parameters include at least one of the following: the length of the upper base of the trapezoidal waveguide structure, the length of the lower base of the trapezoidal waveguide structure, the height of the trapezoidal waveguide structure, the length of the rectangular waveguide structure, the width of the rectangular waveguide structure, the height of the rectangular waveguide structure, and the number of splitting ends.

4. The beam splitter according to claim 3, characterized in that, The performing iterative calculations on the structural parameters of the beam splitter includes: Performing iterative calculations on the structural parameters of the beam splitter based on the particle swarm optimization algorithm.

5. The beam splitter according to claim 4, characterized in that, The performing iterative calculations on the structural parameters of the beam splitter based on the particle swarm optimization algorithm includes: Constructing the initial position variable and the initial velocity variable of the particles in the particle swarm optimization algorithm according to the structural parameters of the beam splitter; Obtaining the updated position variable and the updated velocity variable according to the initial position variable, the initial velocity variable, and the iterative update relationship of the particle swarm optimization algorithm; Obtaining the output result of the beam splitter according to the position variable and the velocity variable; the position variable includes the initial position variable and the updated position variable, and the velocity variable includes the initial velocity variable and the updated velocity variable.

6. The beam splitter according to claim 5, wherein The expression of the initial position variable is: X i = [x1, x2, x3, …, x n ​ The expression of the initial velocity variable is: V i = [v1, v2, v3, …, v n ​ The expression of the updated position variable is: The expression of the updated velocity variable is: Among them, X i represents the initial position variable of the i-th particle, where i represents the particle sequence number; x n represents the structural parameter; n = 1, 2, …, N, where N represents the number of independent variables and n represents the independent variable sequence number; V i represents the initial velocity variable of the i-th particle; v n represents the velocity of change of x n ; d = 1, 2, 3, …, K, where K represents the number of iterations and d represents the iteration sequence number; V i d represents the velocity variable of the i-th particle after the d-th iteration update; represents the position variable of the i-th particle after the d-th iteration update; w, c1, r1, c2, and r2 represent coefficients; represents the historical best position searched by the i-th particle after the d-th iteration; g best d represents the historical best position of the population in the d-th iteration.

7. The beam splitter according to any one of claims 3-6, characterized in that, The trapezoidal waveguide structure is an isosceles trapezoidal waveguide structure.

8. The beam splitter according to claim 7, characterized in that, The verification condition is as follows: verifying the calculation result of the iterative calculation based on the following first verification formula, and taking the calculation result that satisfies the first verification formula as the determined structural parameter. The expression of the first verification formula is as follows: Among them, FOM1 represents the first verification formula, M represents the number of shunt ends, T represents the number of optical wave wavelengths, and P m (λ t ) is the actual output power of the m-th shunt end at the t-th wavelength, and P m represents the target output power of the m-th shunt end.

9. The beam splitter according to claim 8, wherein, The beam splitter is a multi-channel equal-splitting optical power splitter, and P m = 1 / M.

10. The beam splitter according to any one of claims 3-6, characterized in that, The trapezoidal waveguide structure is a non-isosceles trapezoidal waveguide structure.

11. The beam splitter according to claim 10, wherein The verification condition is as follows: verifying the calculation result of the iterative calculation based on the following second verification formula, and taking the calculation result that satisfies the second verification formula as the determined structural parameter. The expression of the second verification formula is as follows: Among them, FOM2 represents the second verification formula, M represents the number of shunt ends, T represents the number of optical wave wavelengths, and P m (λ t ) is the actual output power of the m-th shunt end at the t-th wavelength, and P m represents the target output power of the m-th shunt end.

12. The beam splitter according to any one of claims 1-11, characterized in that, The rectangular waveguide structure is a sub-wavelength structure.

13. The beam splitter according to any one of claims 1-12, characterized in that, The beam splitter is a wavelength division multiplexer.

14. An optical module, characterized in that, It includes a mounting liner and a beam splitter; the beam splitter is arranged on the mounting liner; The beam splitter includes a multiplexing end, a tapered waveguide structure and a plurality of demultiplexing ends; the tapered waveguide structure includes at least two trapezoidal waveguide structures and at least one rectangular waveguide structure; wherein: the at least two trapezoidal waveguide structures are cascaded, and for two adjacent trapezoidal waveguide structures among the at least two trapezoidal waveguide structures, coupling between the two adjacent trapezoidal waveguide structures is achieved based on one rectangular waveguide structure among the at least one rectangular waveguide structure; the multiplexing end is coupled to the first-stage trapezoidal waveguide structure among the at least two cascaded trapezoidal waveguide structures, and the plurality of demultiplexing ends are coupled to the last-stage trapezoidal waveguide structure among the at least two cascaded trapezoidal waveguide structures.

15. An optical chip, characterized in that, It includes a mounting liner and the beam splitter according to any one of claims 1-13; the beam splitter is arranged on the mounting liner.

16. An electronic device, characterized in that, It includes: A controller and the optical module according to claim 14, the controller being coupled to the optical module; Or, a controller and the optical chip according to claim 15, the controller being coupled to the optical chip.

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