Multiplexer, design method and multi-channel hybrid multiplexer

Abstract

The application provides a multiplexer, a design method and a multi-channel hybrid multiplexer. The multiplexer comprises an input waveguide, an optimization area and a bus waveguide connected in sequence. The optimization area is divided into multiple units, each unit has two states, and the state of each unit is obtained according to an optimization mode. The optimization mode is as follows: the state of at least one unit in a pooling window is changed, if the output spectrum of the optimization area after the state is changed is closer to a target output spectrum than the output spectrum of the optimization area before the state is changed, the state of the changed pooling window is kept; all units are traversed according to the above mode until stability is reached; and the pooling window is a set of at least one unit. The application calculates and sets the optimization area with the optimal performance through the optimization mode of the pooling window, accelerates the optimization speed, improves the optimization effect, connects the optimization area with multiple input waveguides and synchronously transmits into the bus waveguide, reduces the overall design size, and further improves the transmission capacity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of multiplexer, and particularly relates to a multiplexer, a design method and a multi-channel hybrid multiplexer. BACKGROUND

[0002] With the rapid development of integrated photonics and complementary metal-oxide-semiconductor manufacturing technology, silicon photonics based on silicon-on-insulator technology has broad application prospects in future high-speed optical interconnections.

[0003] It is known that the wavelength division multiplexing technology can expand the communication capacity through multiple wavelengths. In addition to the traditional wavelength division multiplexing technology, the mode division multiplexing technology can carry multi-channel data through the orthogonal eigenmodes in a multimode optical waveguide, which is an effective way to improve the transmission capacity of an optical interconnection system. The mode division multiplexer is an important component of the mode division multiplexing system. The mode division multiplexer usually adopts a forward design method, such as the asymmetric coupling principle, to simply realize a mode division multiplexer of multiple modes, but the size is too large, and it is not easy to be applied to a high-density integrated photonics circuit. The multiplexer obtained by using other design methods is also difficult to realize consistent improvement in size, optimization speed and effect, and is difficult to meet actual needs. SUMMARY

[0004] The technical problem to be solved by the application is to provide a multiplexer, a design method and a multi-channel hybrid multiplexer to solve the problems of large size, small number of channels and poor performance of the multiplexer in the prior art.

[0005] To achieve the above object, the technical scheme adopted by the present application is to provide a multiplexer, comprising an input waveguide, an optimization area and a bus waveguide connected in sequence, the optimization area is divided into multiple units, each unit has 2 states, and the state of each unit is obtained according to an optimization method; the optimization method is to change the state of at least one unit in a pooling window, if the output spectrum of the optimization area after the state is changed is closer to the target output spectrum than the output spectrum of the optimization area before the state is changed, the state of the changed pooling window is retained; all the pooling windows are traversed according to the above method until stable; and the pooling window is a set of at least one unit.

[0006] Among them, the target output spectrum is usually the embodiment of the ideal performance of the target device, and the optimization area is to realize the multiplexing of T TE0 , T TE1 , T TE2 , and T TE3 modes, so the target output spectrum is to make the transmittance of T TE0 , T TE1 , T TE2 , and T TE3 modes as large as possible, which can be usually expressed by the following formula:

[0007] FOM = T TE0 + T TE1 + T TE2 + T TE3

[0008] wherein T TE0 , T TE1 , T TE2 , and T TE3 represent the transmittance of TE0, TE1, TE2, and TE3 modes at 1550 nm wavelength, respectively, and FOM is the figure of merit.

[0009] The greater the FOM value of the output spectrum after the change, the higher the transmittance of TE0, TE1, TE2, and TE3 modes, and the better the performance of the device, and thus the state of the unit after the change is retained, otherwise, the state of the unit before the change is retained.

[0010] Correspondingly, the stable state usually refers to the difference between the output spectra after 2 iterations (traversing all the pooling windows, which is one iteration) is less than a set value, such as 0.1%, that is, it is judged that the optimization area is in a stable state, and the optimization iteration process is stopped, otherwise, the iteration optimization is continued.

[0011] Optionally, the state of the unit is divided into an etched state and a non-etched state.

[0012] Optionally, the etching manner is to punch a hole in the center of the unit, or to fill other materials different from the material of the unit after punching a hole in the center of the unit.

[0013] Optionally, the number of input waveguides is at least 2.

[0014] Optionally, the cross section of the optimization area is a pentagon.

[0015] Optionally, in the process of traversing the above pooling window, the state of one or more units in the entire optimization area is randomly changed in sequence, and if the output spectrum after the change is closer to the target output spectrum than the original output spectrum, the state of the unit in the changed pooling window is retained.

[0016] The multiplexer of the present application is mainly a TE mode multiplexer.

[0017] The application also provides a design method of a multiplexer, comprising the following steps: dividing an optimization area into a plurality of units, each unit having two states, initializing the state of each unit in the optimization area; taking a set of at least one unit as a pooling window, and randomly changing the state of at least one unit in the pooling window; if the output spectrum of the optimization area after the state is changed is closer to the target output spectrum than the output spectrum of the optimization area before the state is changed, then the state of the unit in the pooling window after the change is retained; and traversing all the pooling windows in the above manner until stability.

[0018] Optionally, in the process of traversing the above-mentioned pooling window, the state of one or more units in the entire optimization area is randomly changed in sequence, and if the output spectrum after the state is changed is closer to the target output spectrum than the original output spectrum, then the state of the unit in the pooling window after the change is retained.

[0019] The application also provides a multi-channel hybrid multiplexer, comprising the above-mentioned multiplexer, mainly a TE mode multiplexer, and at least one other polarization mode multiplexer, such as a TM mode polarization multiplexer, wherein the other polarization mode multiplexer comprises an input end, a bent waveguide and a coupling waveguide connected in sequence, and the coupling waveguide and the bus waveguide form an asymmetric directional coupler unit.

[0020] Optionally, different asymmetric directional coupler units are cascaded to form a TM mode polarization multiplexer.

[0021] Optionally, the TE mode multiplexer has four input waveguides, each of the four input waveguides is connected with the optimization area and connected with the bus waveguide through the optimization area, and the multiplexing of TE0, TE1, TE2 and TE3 modes can be realized.

[0022] The width of the bus waveguide near one end of the optimization area is different from the width of the bus waveguide away from one end of the optimization area, a first output waveguide is formed at the end of the bus waveguide near the optimization area, and a second output waveguide is formed at the end of the bus waveguide away from the optimization area.

[0023] The TM mode polarization multiplexer is composed of three TM mode asymmetric directional coupler units cascaded, according to the asymmetric directional coupling principle, by controlling the structural parameters of the coupling waveguide and the bus waveguide, the multiplexing of TM0, TM1, TM2 and TM3 modes can be realized.

[0024] The application also provides a surrounding structure, which comprises a substrate and an upper cladding layer, and the substrate and the upper cladding layer wrap the outside of the multi-channel hybrid multiplexer.

[0025] The beneficial effect of the present application is that the optimal performance of the optimization area is calculated and set by setting the optimization mode of the pooling window, which accelerates the optimization speed and improves the optimization effect, and further improves the transmission performance through the optimization area. The TE mode multiplexer optimized by the optimization area and the TM mode multiplexer composed of the TM mode asymmetric directional coupler unit in series, through the common bus waveguide combination, form a mixed polarization multiplexer, which greatly reduces the size of the device and increases the number of channels. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A structure schematic diagram of a multi-channel mixed multiplexer according to an embodiment of the present application;

[0027] Figure 2 A top view structure schematic diagram of a multi-channel mixed multiplexer according to an embodiment of the present application;

[0028] Figure 3 A structure schematic diagram of an optimization area in a multi-channel mixed multiplexer according to an embodiment of the present application;

[0029] Figure 4 A calculation principle schematic diagram of an optimization area in a multi-channel mixed multiplexer according to an embodiment of the present application;

[0030] Figure 5 A flowchart of a design method of a multiplexer according to an embodiment of the present application;

[0031] Figure 6 A simulation result of a TE polarization mode of a multi-channel mixed multiplexer according to an embodiment of the present application;

[0032] Figure 7 A simulation result of a TM polarization mode of a multi-channel mixed multiplexer according to an embodiment of the present application;

[0033] Figure 8 A comparison between a search pooling window design method and a design method of sequentially searching units according to the present application.

[0034] In the drawings, various reference signs represent:

[0035] 11-input waveguide, 12-optimization area, 13-bus waveguide, 20-TM mode polarization multiplexer, 21-input end, 22-bent waveguide, 23-coupling waveguide, 30-enclosing structure, 31-substrate, 32-upper cladding layer;

[0036] 211-first input end, 221-first bent waveguide, 231-first coupling waveguide;

[0037] 212-second input end, 222-second bent waveguide, 232-second coupling waveguide;

[0038] 213 - third input end, 223 - third curved waveguide, 233 - third coupling waveguide;

[0039] 111 - first input waveguide, 112 - second input waveguide, 113 - third input waveguide, 114 - fourth input waveguide; 131 - first output waveguide, 132 - second output waveguide, 133 - tapered waveguide. DETAILED DESCRIPTION

[0040] In order to make the objects, technical solutions and advantages of the present application clearer, the following will describe the technical solutions in the embodiments of the present application in detail with reference to the drawings of the preferred embodiments of the present application. In the drawings, the same or similar notations represent the same or similar parts or parts having the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, rather than all the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0041] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixedly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0043] The terms "first", "second", "third" (if present) in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0044] Furthermore, the terms "comprise", "comprising", "have", "having", "include", "including", "contain", "containing", "provide", "providing", "offer", "offering", "specify", "specifying", "preserve", "preserving" and their any variations thereof, are meant to cover a non-exclusive inclusion, for example, a process, a method, a system, a product, or a maintenance tool including a series of steps or units not necessarily in the same order as they are clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products, or maintenance tools.

[0045] As shown in the accompanying drawings Figures 1-8 The present application provides a multiplexer, comprising an input waveguide 11, an optimization area 12 and a bus waveguide 13 connected in sequence, the optimization area 12 is divided into a plurality of units, each unit has 2 states, and the state of each unit is obtained according to an optimization method; the optimization method is to change the state of at least one unit in the pooling window, if the output spectrum of the optimization area after changing the state is closer to the target output spectrum than the output spectrum of the optimization area before changing the state, then the state of the changed pooling window is retained; all the pooling windows are traversed according to the above method until stable; the pooling window is a set of at least one unit.

[0046] Wherein, the target output spectrum is usually the embodiment of the ideal performance of the target device. It is selected based on actual operation.

[0047] After selecting the target output spectrum, the states of the units in the optimization area 12 are changed to obtain different output spectrums, and the states of the output spectrums closer to the target are retained in this process. After traversing all the pooling windows in the optimization area 12, the states of the units of the optimal output spectrum are obtained. Wherein, one traversal is one iteration of the optimization area 12. In this step of the present application, multiple iterations are usually required to optimize the optimization area 12.

[0048] It can be understood that when comparing each iteration, a judgment value is usually required to determine the optimization effect, so as to determine whether to continue the next iteration. Wherein, the judgment value is usually the difference between the output spectrums of 2 iterations. For example, in this embodiment, the difference value is usually set to 0.1%, and when the difference between the output spectrums of 2 iterations is less than 0.1%, it is judged that the optimization area is in a stable state, and the optimization process is stopped.

[0049] In this process, the states of one or more units of the entire optimization area can also be changed randomly in sequence, and if the output spectrum after changing the state is closer to the target output spectrum than the original output spectrum, then the state of the changed unit is retained, so as to realize the randomness of the change and achieve better optimization effect.

[0050] In addition, in the embodiment, each unit has two states, and the state of each unit is changed by optimization, so as to realize optimization. Alternatively, the state of the unit is divided into etching state and non-etching state. For example, in the algorithm, in order to facilitate the expression of the structure of the optimization area, each unit has two optional states of "0" and "1", wherein "0" represents that the unit is in the etching state, and "1" represents that the unit is in the non-etching state.

[0051] It should be noted that the pooling window is a set of at least one unit, that is, when the state of the unit in the pooling window is changed, at least one unit is always retained in the pooling window. When there are a plurality of units in the pooling window, one or more of the plurality of units can be randomly selected for state change, so as to increase the randomness of optimization, avoid premature local convergence, and accelerate the convergence speed of optimization without traversing all units in the pooling window.

[0052] In the embodiment, the size of the pooling window is 2*2, that is, there are four units in one pooling window, and the embodiment is not limited thereto. It can be understood that there are four units in the pooling window, and the initial states of the four units are randomly set. One or more units in the pooling window are randomly selected and the states thereof are changed in sequence. In the embodiment, two units are randomly selected and the states thereof are changed in sequence. After each change, the spectral performance after output is calculated. When it is determined that the performance difference between the output spectrum after change and the target spectrum becomes larger, the state of the unit before change is retained. When it is determined that the output spectrum after change is closer to the target spectrum, the state of the unit after change is retained. After the selected state is changed, the state of the unit in the next pooling window is changed and detected.

[0053] In the above embodiment, it can be understood that the etching manner can generally be that a hole is punched in the center of the unit, or other materials different from the unit material are filled after the hole is punched in the center of the unit. The punching can also be understood as filling air material. For example, the unit material is set as a silicon cube with a length and width of 0.12 μm and a depth of 0.22 μm, "0" represents the etching state, the unit can be punched, that is, the filling material is air, the diameter D of the hole is 90 nm, or a silica cylinder with a diameter D of 90 nm is filled in the center of the cube. In the present application, "0" represents the etching state, and a silica cylinder with a diameter D of 90 nm is selected to be filled in the center of the silicon cube with a length and width of 0.12 μm and a depth of 0.22 μm; "1" represents that the cube remains unchanged as a silicon material, so as to change the state of the unit.

[0054] Exemplarily, the multiplexer provided in the present application can be set as a TE mode multiplexer. In the multiplexer, a plurality of input waveguides 11 are usually provided, and the plurality of input waveguides 11 are respectively connected with the optimization region 12. Exemplarily, the input waveguides 11 are provided as four, and the four input waveguides 11 are arranged at intervals on the same side of the optimization region 12, and the other side of the optimization region 12 is connected with the bus waveguide 13. In the multiplexer, the input waveguides 11 are all used for inputting TE0 mode. In order to achieve the effect of lossless support of TE0 mode, optionally, the width of the four input waveguides 11 is all set as 0.5 μm. In the multiplexer, the optical signals of TE0 mode are injected from the input waveguides 11, and can be respectively converted into TE0, TE1, TE2 and TE3 modes by the optimization region 20 and output from the bus waveguide 13. In addition, the optimization region 20 can be set as a pentagon to reduce the optimization area surface and save the optimization time.

[0055] In the present application, a design method of the TE mode multiplexer is also provided, which comprises the following steps: (1) dividing the optimization region into a plurality of units, each unit has two states, and initializing the state of each unit in the optimization region; (2) taking at least one set of units as a pooling window, and changing the state of at least one unit in the pooling window in turn at random; (3) if the output spectrum of the optimization region after the state is changed is closer to the target output spectrum than the output spectrum of the optimization region before the state is changed, then the state of the changed unit is reserved; and (4) traversing all the pooling windows in the above manner until stable.

[0056] Correspondingly, in order to increase the random disturbance in the optimization process, before step (4), the method further comprises the following steps: in the process of the above traversal, changing the state of one or more units of the whole optimization region at random, and if the output spectrum after the state is changed is closer to the target output spectrum than the original output spectrum, then the state of the changed unit is reserved. In the process of changing the state of at least one unit of the whole optimization region at random, when one unit is selected, the unit of the optimization region can be directly selected at random, and when a plurality of units are selected, the states of the units selected from the pooling window can be changed in turn according to the random selection order, and the technical effect of random disturbance can be achieved, which is not limited in the present application.

[0057] In the above process, when the performance of the output spectrum is detected, the following formula can be used for judgment:

[0058] FOM = T TE0 + T TE1 + T TE2 + T TE3

[0059] T TE0 , T TE1 , T TE2 , and T TE3TE0, TE1, TE2, and TE3 mode transmittance at 1550 nm wavelength, and FOM is a figure of merit. By comparing the FOM with a set value, whether a steady state is reached is analyzed to determine whether a next iteration process needs to be performed.

[0060] The optimization design method of the present application can increase random disturbance of search formula optimization, avoid premature local convergence of search formula optimization, and save optimization time by forming a pooling window by grouping multiple units, randomly changing the state of one or more units in the pooling window, and avoiding searching all units.

[0061] In addition, the present application also provides a multi-channel hybrid multiplexer, which comprises the TE mode multiplexer and at least one TM mode polarization multiplexer 20.

[0062] The input end 21, the curved waveguide 22, and the coupling waveguide 23 can be provided with multiple asymmetric directional coupling units in cascade combination to form a TM mode polarization multiplexer supporting multiple TM polarization modes.

[0063] Specifically, in the present application, the TE mode multiplexer has four input waveguides 11, all of which are connected with the optimization area 12 and connected with the bus waveguide 13 through the optimization area 12; the width of the bus waveguide 13 near one end of the optimization area 12 is different from the width of the bus waveguide 13 away from one end of the optimization area 12, the first output waveguide 131 is formed at one end of the bus waveguide 13 near the optimization area 12, and the second output waveguide 132 is formed at one end of the bus waveguide 13 away from the optimization area 12; the input end 21, the curved waveguide 22 and the coupling waveguide 23 are all provided with three, three coupling waveguides 23 form three asymmetric directional coupling units with the first output waveguide 131 and the second output waveguide 132 respectively; it also includes a surrounding structure 30, the surrounding structure 30 includes a substrate 31 and an upper cladding layer 32, the substrate 31 and the upper cladding layer 32 are wrapped outside the multi-channel hybrid multiplexer. Among them, the substrate 31 and the upper cladding layer 32 can be set as a medium different from the material of the multi-channel hybrid multiplexer, for example, the material of the substrate 31 can be set as 2μm thick silicon dioxide, the upper cladding layer 32 is 2μm thick silicon dioxide, and the material of the multi-channel hybrid multiplexer structure is 0.22μm thick silicon, which is not limited in the present embodiment.

[0064] Specifically, the TE mode multiplexer has a first input waveguide 111, a second input waveguide 112, a third input waveguide 113 and a fourth input waveguide 114, the bus waveguide 13 is formed with a first output waveguide 131 and a second output waveguide 132, and the first output waveguide 131 and the second output waveguide 132 are connected through a tapered waveguide 133. The TM mode multiplexer 20 includes a first input end 211, a first curved waveguide 221 and a first coupling waveguide 231 connected in sequence, a second input end 212, a second curved waveguide 222 and a second coupling waveguide 232 connected in sequence, and a third input end 213, a third curved waveguide 223 and a third coupling waveguide 233 connected in sequence. The input waveguide, the curved waveguide and the coupling waveguide are connected in sequence and have the same width.

[0065] Exemplarily, the widths of the first input waveguide 111, the second input waveguide 112, the third input waveguide 113 and the fourth input waveguide 114 can be all set to 0.5 μm to support TE0 mode without loss, and the intervals between the first input waveguide 111 and the second input waveguide 112, the second input waveguide 112 and the third input waveguide 113, and the third input waveguide 113 and the fourth input waveguide 114 are all set to 800 nm. Correspondingly, the width of the first output waveguide 131 is set to 1.68 μm to support TE0, TE1, TE2 and TE3 modes. Correspondingly, in order to achieve the optimization effect of the optimization region 12, the optimization region 12 is set to a pentagon to reduce the surface area of the optimization region 12, and the side lengths W1, W2, W3, W4 and W5 of the optimization region 12 are 5.4 μm, 4.92 μm, 2.7 μm, 3.65 μm and 2.46 μm respectively.

[0066] In the optimization process, the optimization region shown in FIG. 2A can be obtained. Figure 2 After the TE0 mode optical signals are input by the first input waveguide 111, the second input waveguide 112, the third input waveguide 113 and the fourth input waveguide 114 respectively, the optical signals pass through the optimization region 12 and are transmitted into the bus waveguide 13, and are converted into TE0, TE1, TE2 and TE3 modes respectively and output from the first output waveguide 131.

[0067] Correspondingly, the TM mode polarization multiplexer 20 provided by the application is composed of cascaded asymmetric directional coupler units, wherein the first coupling waveguide 231 and the second output waveguide 132 constitute a TM0-TM3 asymmetric directional coupler to couple and convert the input TM0 mode into a TM3 mode; the second coupling waveguide 232 and the first output waveguide 131 constitute a TM0-TM1 asymmetric directional coupler to couple and convert the input TM0 mode into a TM1 mode; and the third coupling waveguide 233 and the first output waveguide 131 constitute a TM0-TM2 asymmetric directional coupler to convert the input TM0 mode into a TM2 mode.

[0068] Correspondingly, the 3-channel TM mode polarization multiplexer 20 is composed of TM0-TM1 asymmetric directional coupler, TM0-TM2 asymmetric directional coupler and TM0-TM3 asymmetric directional coupler in cascade, and the specific working principle is as follows: TM0 mode is injected from the first input end 211, the second input end 212 and the third input end 213, and can be converted into TM3, TM1 and TM2 modes output from the bus waveguide 13 respectively. Among them, the TM0-TM1 asymmetric directional coupler converts the TM0 mode of the second coupling waveguide 232 into the TM1 mode of the first output waveguide 131, according to the coupling principle, the width of the first output waveguide 131 is 1.68 μm, and the width of the corresponding second coupling waveguide 232 is about 0.731 μm; the TM0-TM2 asymmetric directional coupler converts the TM0 mode of the third coupling waveguide 233 into the TM2 mode of the first output waveguide 131, according to the coupling principle, the width of the first output waveguide 131 is 1.68 μm, and the width of the corresponding third coupling waveguide 233 is about 0.38 μm; the TM0-TM3 asymmetric directional coupler converts the TM0 mode of the first coupling waveguide 231 into the TM3 mode of the second output waveguide 132, and the width of the first coupling waveguide 231 is set to 0.38 μm, which can effectively support the TM0 mode, according to the coupling principle, the width of the corresponding second output waveguide 132 is about 2.336 μm.

[0069] In the present application, since the TE mode multiplexer is designed by using an intelligent algorithm, the size is greatly reduced, thereby reducing the size of the entire TE and TM hybrid multiplexer while ensuring the number of channels. The simulation results of the hybrid multiplexer are shown in Figure 6 and Figure 7 When TE0 mode is input from the first input waveguide 111, the second input waveguide 112, the third input waveguide 113 and the fourth input waveguide 114, it is converted into TE0, TE1, TE2 and TE3 modes output from the bus waveguide 13 respectively, and the insertion loss at 1550 nm is 0.5 dB, 0.8 dB, 1.0 dB and 1.3 dB respectively, and the crosstalk at 1550 nm is less than –23.9 dB, –23.8 dB, –21.1 dB and –20.3 dB respectively. When TM0 mode is input from the first input end 211, the second input end 212 and the third input end 213, it is converted into TM1, TM2 and TM3 modes output from the bus waveguide 13 respectively, and the insertion loss at 1550 nm is 0.2 dB, 0.4 dB and 0.3 dB respectively, and the crosstalk at 1550 nm is less than –25.5 dB, –25.7 dB and –35.0 dB respectively. Compared with the prior art, the size of the entire device is greatly reduced in the case of multiple channels, and the transmission capacity is further improved.

[0070] The search of the optimization area by setting the pooling window increases the randomness of the optimization, avoids premature local convergence, and does not need to traverse all the cells in the pooling window, thus accelerating the convergence speed of the optimization. Similarly, in the process of searching the pooling window, the state of one or more cells in the entire optimization area is changed randomly and sequentially, and then calculation is performed, which also increases the randomness of the optimization, avoids premature local convergence, and improves the optimization effect. Figure 8 It can be seen that, in terms of the performance of the device and the convergence speed, the search by the pooling window is better than the search of the cells in sequence.

[0071] Those skilled in the art should understand that the above discussion of any embodiment is only exemplary and is not intended to imply that the protection scope of the present application is limited to these examples; the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of one or more embodiments of the present application as described above. In order to be brief, they are not provided in details.

[0072] One or more embodiments of the present application are intended to cover all such replacements, modifications and variations falling within the broad scope of the present application. Therefore, any omission, modification, equivalent replacement, improvement, etc. made in the spirit and principles of one or more embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A multi-channel hybrid multiplexer, characterized in that, The device includes a multiplexer and at least one multiplexer for other polarization modes, the other polarization mode multiplexer comprising an input terminal, a bent waveguide and a coupling waveguide connected in sequence, the coupling waveguide and the bus waveguide forming an asymmetric directional coupler unit; The multiplexer includes an input waveguide, an optimization region, and a bus waveguide connected in sequence. The optimization region is divided into multiple units, each with two states. The state of each unit is obtained according to an optimization method. The optimization method involves changing the state of at least one unit within a pooling window. If the output spectrum of the optimization region after the state change is closer to the target output spectrum than the output spectrum of the optimization region before the state change, then the changed pooling window state is retained. This process is repeated for all pooling windows until stability is achieved. The pooling window is a set of at least one unit. The multiplexer has four input waveguides, all of which are connected to the optimization region and are connected to the bus waveguide through the optimization region. The width of the bus waveguide near the optimization region is different from the width of the end away from the optimization region. A first output waveguide is formed at the end of the bus waveguide near the optimization region, and a second output waveguide is formed at the end of the bus waveguide away from the optimization region. The multiplexer for other polarization modes is composed of three cascaded asymmetric directional coupler units for other polarization modes; It also includes an enclosure structure comprising a substrate and an upper cladding layer, the substrate and the upper cladding layer being disposed on the outside of the multichannel hybrid multiplexer.

2. The multi-channel hybrid multiplexer as described in claim 1, characterized in that, The state of the unit is divided into etched state and non-etched state.

3. The multi-channel hybrid multiplexer as described in claim 2, characterized in that, The etching method involves drilling a hole in the center of the cell, or drilling a hole in the center of the cell and then filling it with a material that is different from the cell material.

4. The multi-channel hybrid multiplexer as described in claim 1 or 2, characterized in that, The cross-section of the optimization region is pentagonal.

5. The multi-channel hybrid multiplexer as described in claim 1 or 2, characterized in that, During the above traversal process, the state of one or more units in the entire optimization region is randomly changed. If the output spectrum after the change is closer to the target output spectrum than the original output spectrum, the state of the units in the changed pooling window is retained.

6. The multi-channel hybrid multiplexer as described in claim 1, characterized in that, Different asymmetric directional coupler units are cascaded to form multiplexers for other polarization modes.

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