Silicon-based integrated wavelength division multiplexer and operating method thereof

Abstract

The present invention provides a silicon-based integrated wavelength division multiplexer and an operating method thereof. The silicon-based integrated wavelength division multiplexer includes a first adjustable optical splitter, a first unbalanced arm, and a second adjustable optical splitter. The first unbalanced arm includes a first waveguide arm and a second waveguide arm. The first waveguide arm includes a first waveguide segment, a second waveguide segment, a third waveguide segment, a fourth waveguide segment, a fifth waveguide segment, a sixth waveguide segment, and a seventh waveguide segment arranged in sequence. The third waveguide segment and the fifth waveguide segment are symmetrically arranged and have a first width. The second waveguide segment and the sixth waveguide segment are symmetrically arranged and have a second width. The second waveguide arm includes an eighth waveguide segment, a ninth waveguide segment, a tenth waveguide segment, an eleventh waveguide segment, a twelfth waveguide segment, a thirteenth waveguide segment, and a fourteenth waveguide segment. A first thermo-optical phase shifter is provided above the fourth waveguide segment. The present invention also provides an operating method for the aforementioned silicon-based integrated wavelength division multiplexer. The wavelength division multiplexer of the present invention covers a wide bandwidth range.

Description

Technical Field

[0001] The present invention relates to the technical field of optical communication devices, in particular to a silicon-based integrated wavelength division multiplexer and a working method of the optical circulator. Background Art

[0002] Wavelength division multiplexers (WDMs) are common optical devices. With the increasing integration and miniaturization of optical devices, coarse wavelength division (WDM) multiplexers (DDMs) implemented on silicon-based photonics platforms are increasingly being used in various optical devices. Currently, a common approach to implementing coarse WDM (DDM) on silicon-based photonics platforms is to use a cascaded Mach-Zehnder interferometer (MZI) structure based on passive components. For example, patent application publication number CN116381862A discloses a Mach-Zehnder interferometer (MZI) cascaded comb filter and WDM / DDM.

[0003] However, existing silicon-based integrated wavelength division multiplexers (WDMs) have the following limitations: First, the wavelength channels of traditional silicon-based four-way (DWDM) multiplexers are fixed. Since DWDMs are fully passive devices, they can only operate within four fixed CWDM (coarse wavelength division multiplexing) wavelength channels after manufacturing, covering a bandwidth of only 80nm. However, the ITU-T G.694.2 CWDM standard covers a wider wavelength range (from the O to L bands), making traditional WDMs difficult to meet such broad wavelength division multiplexing and demultiplexing requirements. Second, traditional WDMs have limited bandwidth. Due to the coupling ratio dispersion of silicon-based couplers, traditional WDMs are generally limited to an 80nm wavelength bandwidth. Third, traditional WDMs are sensitive to manufacturing variations, resulting in limited insertion loss and crosstalk performance. This is because the phase difference of the unbalanced arms in traditional WDMs is sensitive to variations in the manufactured waveguide width and height. Fourth, traditional (de)WDM multiplexers are significantly affected by ambient temperature. Due to the large refractive index difference between the waveguide and cladding in silicon-based photonics platforms, the unbalanced arm phase difference and the coupling ratio of the coupler are highly sensitive to temperature, causing spectrum drift and increased crosstalk in traditional (de)WDM multiplexers. Fifth, traditional (de)WDM multiplexers cannot meet the requirements of real-time wavelength switching and automatic upgrades of coarse wavelength division multiplexing optical paths.

[0004] Therefore, it is necessary to improve the silicon-based integrated wavelength division multiplexer so that the silicon-based integrated wavelength division multiplexer can cover a wider bandwidth range and meet the usage requirements of more scenarios. Summary of the Invention

[0005] The first object of the present invention is to provide a silicon-based integrated wavelength division multiplexer covering a wide bandwidth range.

[0006] A second object of the present invention is to provide a method for operating the aforementioned silicon-based integrated wavelength division multiplexer.

[0007] To achieve the above-mentioned first purpose, the silicon-based integrated wavelength division multiplexer provided by the present invention has at least one first-level wavelength division multiplexing unit, and the first-level wavelength division multiplexing unit includes a first adjustable optical splitter, a first unbalanced arm, and a second adjustable optical splitter arranged in sequence; the first unbalanced arm includes a first waveguide arm and a second waveguide arm, and the first waveguide arm and the second waveguide arm are both U-shaped, and the first waveguide arm includes a first waveguide segment, a second waveguide segment, a third waveguide segment, a fourth waveguide segment, a fifth waveguide segment, a sixth waveguide segment, and a seventh waveguide segment arranged in sequence, wherein the third waveguide segment and the fifth waveguide segment are arranged in sequence. The waveguide segments are symmetrically arranged and have a first width, the second waveguide segment and the sixth waveguide segment are symmetrically arranged and have a second width; the second waveguide arm includes an eighth waveguide segment, a ninth waveguide segment, a tenth waveguide segment, an eleventh waveguide segment, a twelfth waveguide segment, a thirteenth waveguide segment, and a fourteenth waveguide segment arranged in sequence, wherein the ninth waveguide segment and the thirteenth waveguide segment are symmetrically arranged and have a first width, the tenth waveguide segment and the twelfth waveguide segment are symmetrically arranged and have a second width, and the first width is greater than the second width; and a first thermo-optical phase shifter is covered above the fourth waveguide segment.

[0008] As can be seen from the above scheme, in the first waveguide arm and the second waveguide arm of the first unbalanced arm of the present invention, since the lengths and widths of the waveguide segments are not exactly the same, the time delays incurred by the light beam after passing through the first waveguide arm and the second waveguide arm are also different. Furthermore, because the first thermo-optical phase shifter is only located above the fourth waveguide segment of the first waveguide arm, the operating wavelength of the first unbalanced arm can be changed by applying a corresponding voltage to the first thermo-optical phase shifter based on the actual ambient temperature and the wavelength of the light beam to be split. Therefore, the operating wavelength corresponding to each level of wavelength division multiplexing units is not fixed, but can be adjusted by applying a corresponding voltage to the first thermo-optical phase shifter based on actual conditions, thereby covering a wider bandwidth range and expanding the operating wavelength range of the silicon-based integrated wavelength division multiplexer.

[0009] A preferred solution is that the length of the third waveguide segment is smaller than the length of the second waveguide segment, and the length of the ninth waveguide segment is larger than the length of the tenth waveguide segment.

[0010] It can be seen that since the lengths of the third waveguide segment and the second waveguide segment of the first waveguide arm are different, and the lengths of the ninth waveguide segment and the tenth waveguide segment of the second waveguide arm are also different, the first unbalanced operating wavelength can be ensured to be within the bandwidth range of 250 nm, and the free spectral range basically does not change with the wavelength, thereby ensuring the operating stability of the first unbalanced arm.

[0011] A further solution is that the length of the third waveguide segment is smaller than the length of the ninth waveguide segment, and the length of the second waveguide segment is larger than the length of the tenth waveguide segment.

[0012] A further solution is that the fourth waveguide segment is in an arc shape and has a third width, and the eleventh waveguide segment is in an arc shape and has a third width; the third width is smaller than the second width.

[0013] It can be seen that the waveguide section between the first waveguide arm and the second waveguide arm is in an arc shape, thereby meeting the requirement that the first waveguide arm and the second waveguide arm are arranged in a U shape.

[0014] A further solution is that the first adjustable optical splitter has a first adiabatic coupler and a second adiabatic coupler, two connecting waveguides are formed between the first adiabatic coupler and the second adiabatic coupler, and a second thermo-optical phase shifter is provided on one of the connecting waveguides.

[0015] It can be seen that a second thermo-optical phase shifter is provided on the first adiabatic coupler. According to the working wavelength requirement of the wavelength division multiplexing unit, a corresponding voltage is applied to the second thermo-optical phase shifter to change the temperature of the second thermo-optical phase shifter, thereby widening the bandwidth of the silicon-based wavelength division multiplexer.

[0016] A further solution is that the first adiabatic coupler and the second adiabatic coupler have the same structure; the first adiabatic coupler has a first waveguide and a second waveguide, the first waveguide includes a fifteenth waveguide segment, a sixteenth waveguide segment and a seventeenth waveguide segment arranged in sequence, and the second waveguide includes an eighteenth waveguide segment, a nineteenth waveguide segment and a twentieth waveguide segment arranged in sequence; the sixteenth waveguide segment and the nineteenth waveguide segment are close to each other to form a coupling segment; the fourth width of the first connection position between the fifteenth waveguide segment and the sixteenth waveguide segment is smaller than the fifth width of the second connection position between the sixteenth waveguide segment and the seventeenth waveguide segment; the sixth width of the third connection position between the eighteenth waveguide segment and the nineteenth waveguide segment is larger than the seventh width of the fourth connection position between the nineteenth waveguide segment and the twentieth waveguide segment; the fifth width is equal to the seventh width.

[0017] It can be seen that the sixteenth waveguide segment and the nineteenth waveguide segment are close to each other to form a coupling segment, and the light beams input from the first waveguide and the second waveguide can couple the light energy in the coupling segment, thereby realizing the redistribution of light energy.

[0018] A further solution is that the distance between the sixteenth waveguide segment and the nineteenth waveguide segment is less than the fifth width. Preferably, the length of the sixteenth waveguide segment is equal to the length of the nineteenth waveguide segment.

[0019] It can be seen that the distance between the sixteenth waveguide segment and the nineteenth waveguide segment is set to be smaller, so that the light beam can couple the light energy in the coupling segment and realize the redistribution of the light energy.

[0020] A further solution is that the coupling ratio of the first adiabatic coupler is between 0.43 and 0.63; and / or the coupling ratio of the second adiabatic coupler is between 0.43 and 0.63.

[0021] As can be seen, the coupling ratios of the first and second adiabatic couplers are both close to 0.5, which means that even distribution of light energy is achieved, meeting the requirements of light splitting. Of course, a reasonable coupling ratio can be set according to the needs of different scenarios.

[0022] To achieve the second objective, the present invention provides an operating method for a silicon-based integrated wavelength division multiplexer, comprising: obtaining a current voltage value of a first thermo-optical phase shifter, and determining a target voltage to be applied to the first thermo-optical phase shifter based on a target wavelength to be split by the silicon-based integrated wavelength division multiplexer; applying the target voltage to the first thermo-optical phase shifter to change the temperature of the first thermo-optical phase shifter; and sequentially inputting light beams containing at least two different wavelengths into a first tunable beam splitter, and using the first tunable beam splitter, a first unbalanced arm, and a second tunable beam splitter to split the input light beams according to wavelength.

[0023] As can be seen from the above scheme, when the silicon-based integrated wavelength division multiplexer is operating, a target voltage is applied to the first thermo-optical phase shifter based on its current voltage value and the wavelength of the light beam to be split, thereby changing the operating wavelength of the first unbalanced arm. Therefore, the operating wavelength corresponding to each level of wavelength division multiplexing units is not fixed. Instead, the operating wavelength can be adjusted by applying a target voltage to the first thermo-optical phase shifter based on actual conditions. This allows for coverage of a wider bandwidth range, thereby expanding the operating wavelength range of the silicon-based integrated wavelength division multiplexer and enabling its application in scenarios requiring wider operating bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural block diagram of an embodiment of a silicon-based integrated wavelength division multiplexer of the present invention.

[0025] Figure 2 This is a structural block diagram of the first adjustable optical splitter in the embodiment of the silicon-based integrated wavelength division multiplexer of the present invention.

[0026] Figure 3 4 is a structural diagram of the first adiabatic coupler in the embodiment of the silicon-based integrated wavelength division multiplexer of the present invention.

[0027] Figure 4 1 is a structural diagram of the first unbalanced arm in an embodiment of the silicon-based integrated wavelength division multiplexer of the present invention.

[0028] Figure 5 The figure is a flow chart of an embodiment of a working method of a silicon-based integrated wavelength division multiplexer of the present invention.

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0030] The silicon-based integrated wavelength division multiplexer of the present invention is used in optical fiber communication networks to split light beams, particularly by wavelength. The silicon-based integrated wavelength division multiplexer of the present invention utilizes a thermo-optical phase shifter to adjust the operating wavelength of the silicon-based integrated wavelength division multiplexer. This allows the operating wavelength of the silicon-based integrated wavelength division multiplexer to be adjusted based on actual conditions rather than fixed, thereby enabling the silicon-based integrated wavelength division multiplexer to cover a wider bandwidth.

[0031] Silicon-based integrated wavelength division multiplexer embodiment:

[0032] See also Figure 1 The silicon-based integrated wavelength division multiplexer of this embodiment has two stages of wavelength division multiplexing units, wherein the first stage wavelength division multiplexing unit includes a first adjustable optical splitter 11, a first unbalanced arm 12, and a second adjustable optical splitter 13 arranged in sequence along the optical path; the number of second stage wavelength division multiplexing units is two, one of which includes a third adjustable optical splitter 14, a second unbalanced arm 15, and a fourth adjustable optical splitter 16 arranged in sequence along the optical path, and the other second stage wavelength division multiplexing unit includes a fifth adjustable optical splitter 17, a third unbalanced arm 18, and a sixth adjustable optical splitter 19 arranged in sequence along the optical path.

[0033] The first tunable optical splitter 11 has two input ports, one of which is used to receive an input optical beam, such as a beam containing multiple different wavelengths, while the other input port does not receive any optical signals. The first tunable optical splitter 11 has two output ports, each connected to the two input ports of the first unbalanced arm 12. The two split optical beams are output through the two output ports and enter the first unbalanced arm 12. The first unbalanced arm 12 has two output ports, each connected to the two input ports of the second tunable optical splitter 13.

[0034] The second adjustable optical splitter 13 has two output ports, one of which is connected to the third adjustable optical splitter 14, and the other is connected to the fifth adjustable optical splitter 17. The third adjustable optical splitter 14 has two input ports, one of which is connected to the second adjustable optical splitter 13, and the other does not receive optical signals. The third adjustable optical splitter 14 has two output ports, which are respectively connected to the two input ports of the second unbalanced arm 15. The two split light beams are output through the two output ports and enter the second unbalanced arm 15. The second unbalanced arm 15 has two output ports, which are respectively connected to the two input ports of the fourth adjustable optical splitter 16. The two output ports of the fourth adjustable optical splitter 16 are O1 and O2, respectively, for outputting light beams of different wavelengths.

[0035] The fifth adjustable optical splitter 17 has two input ports, one of which is connected to the second adjustable optical splitter 13, and the other does not receive optical signals. The fifth adjustable optical splitter 17 has two output ports, respectively connected to the two input ports of the third unbalanced arm 18. The two split light beams are output through the two output ports and enter the third unbalanced arm 18. The third unbalanced arm 18 has two output ports, respectively connected to the two input ports of the sixth adjustable optical splitter 19. The two output ports of the sixth adjustable optical splitter 19 are O3 and O4, respectively, for outputting light beams of different wavelengths. Preferably, the wavelengths of the light beams output by the four output ports O1, O2, O3, and O4 are different.

[0036] In this embodiment, the structures of the first adjustable beam splitter 11, the second adjustable beam splitter 13, the third adjustable beam splitter 14, the fourth adjustable beam splitter 16, the fifth adjustable beam splitter 17, and the sixth adjustable beam splitter 19 are all the same, and the structures of the first unbalanced arm 12, the second unbalanced arm 15, and the third unbalanced arm 18 are also the same.

[0037] The following combination Figure 2 and Figure 3 The structure of the first tunable optical splitter 11 is described below. The first tunable optical splitter 11 comprises a first adiabatic coupler 21 and a second adiabatic coupler 23. Two connecting waveguides, a first connecting waveguide 24 and a second connecting waveguide 25, are formed between the first and second adiabatic couplers 21, 23. A second thermo-optical phase shifter 22 is disposed on the first connecting waveguide 24. In this embodiment, the first and second connecting waveguides 24, 25 are disposed on a silicon waveguide layer, while the second thermo-optical phase shifter 22 is disposed within a silicon dioxide cladding layer above the silicon waveguide layer. Furthermore, the second thermo-optical phase shifter 22 is implemented using a conventional thermo-optical phase shifter.

[0038] In this embodiment, the first insulating coupler 21 and the second insulating coupler 23 have the same structure, and the following description will be made using the first insulating coupler 21 as an example. Figure 3 The first adiabatic coupler 21 includes a first waveguide 31 and a second waveguide 32. The first waveguide 31 includes a fifteenth waveguide segment 35, a sixteenth waveguide segment 36, and a seventeenth waveguide segment 37 arranged in sequence along the optical path. The second waveguide 32 includes an eighteenth waveguide segment 38, a nineteenth waveguide segment 39, and a twentieth waveguide segment 40 arranged in sequence. The sixteenth waveguide segment 36 and the nineteenth waveguide segment 39 are close to each other to form a coupling segment. That is, the distance w between the sixteenth waveguide segment 36 and the nineteenth waveguide segment 39 is g It is relatively small, and the length of the sixteenth waveguide segment 36 is equal to the length of the nineteenth waveguide segment 39, both of which are L0.

[0039] The end of the fifteenth waveguide segment 35 not connected to the sixteenth waveguide segment 36 serves as the input port for the light beam, and the end of the seventeenth waveguide segment 37 not connected to the sixteenth waveguide segment 36 serves as the output port for the light beam. Similarly, the end of the eighteenth waveguide segment 38 not connected to the nineteenth waveguide segment 39 serves as the input port for the light beam, and the end of the twentieth waveguide segment 40 not connected to the nineteenth waveguide segment 39 serves as the output port for the light beam.

[0040] The width of the first connection point 41 between the fifteenth waveguide segment 35 and the sixteenth waveguide segment 36 is the fourth width w a1 , and the second connection position 42 between the sixteenth waveguide segment 36 and the seventeenth waveguide segment 37 has a fifth width w b In this embodiment, the fourth width w a1 Less than the fifth width w b The width of the third connection point 43 between the eighteenth waveguide segment 38 and the nineteenth waveguide segment 39 is the sixth width w a2 , and the fourth connection position 44 between the nineteenth waveguide segment 39 and the twentieth waveguide segment 40 is the seventh width, and the seventh width is equal to the fifth width, both of which are w b . And, the sixth width w a2 is greater than the seventh width, therefore, this embodiment forms w a1 <w b <w a2 Furthermore, the distance w between the sixteenth waveguide segment 36 and the nineteenth waveguide segment 39 is g Relatively small, from Figure 3 It can be seen that the distance w g Less than the fifth width w b In addition, the width of the eighteenth waveguide segment 38 is w r .

[0041] Because the widths of the sixteenth waveguide segment 36 and the seventeenth waveguide segment 37 are not equal, in order to avoid sudden changes in waveguide width, in this embodiment, the first waveguide 31 is processed using a gradual width variation, with the width variation region having a length of L1. Accordingly, the widths of the nineteenth waveguide segment 39 and the twentieth waveguide segment 40 are not equal, and the second waveguide 32 is also processed using a gradual width variation, with the width variation region also having a length of L1.

[0042] By setting a reasonable coupling length between the sixteenth waveguide segment 36 and the nineteenth waveguide segment 39, the light energy of the two incident light beams can be slowly coupled from the first waveguide 31 to the second waveguide 32 during the transmission of the light beams from the input port to the output port. Preferably, the coupling ratio for all wavelengths should be controlled between 0.43 and 0.63, and preferably, the coupling ratio is 0.5. To determine the appropriate length of the coupling segment, simulation software such as FDTD (finite difference time domain method) can be used to observe the changes in light energy within the first adiabatic coupler 21, so that the optimal coupling length can be obtained through simulation to ensure that the first adiabatic coupler 21 can achieve a light energy coupling ratio between 0.43 and 0.63 within a wavelength bandwidth of 250 nm, thereby ensuring that the first adjustable optical splitter 11 can produce a sufficiently wide range of coupling ratios.

[0043] The following combination Figure 4 The structure of the first unbalanced arm 12 is described below. The first unbalanced arm 12 comprises a first waveguide arm 51 and a second waveguide arm 52. The first waveguide arm 51 and the second waveguide arm 52 are both U-shaped. Preferably, the length of the first waveguide arm 51 is equal to the length of the second waveguide arm 52. Figure 4 In the embodiment, the left ports of the first waveguide arm 51 and the second waveguide arm 52 are input ports, and the right ports are output ports.

[0044] The first waveguide arm 51 includes a first waveguide segment 61, a second waveguide segment 62, a third waveguide segment 63, a fourth waveguide segment 64, a fifth waveguide segment 65, a sixth waveguide segment 66, and a seventh waveguide segment 67, which are sequentially arranged along the optical path. The third waveguide segment 63 and the fifth waveguide segment 65 are symmetrically arranged, and the width of the third waveguide segment 63 and the width of the fifth waveguide segment 65 are equal, both having a first width w1. The second waveguide segment 62 and the sixth waveguide segment 66 are symmetrically arranged, and the width of the second waveguide segment 62 and the width of the sixth waveguide segment 66 are equal, both having a second width w2. Figure 4 It can be seen that the first width w1 is greater than the second width w2. In addition, the widths of the first waveguide segment 61, the fourth waveguide segment 64, and the seventh waveguide segment 67 are equal, namely the third width w0. In this embodiment, the third width w0 is less than the second width w2.

[0045] In addition, the fourth waveguide segment 64 is in an arc shape, the length of the middle section of the fifth waveguide segment 65 is L3, and the length of the transition section between the fifth waveguide segment 65 and the fourth waveguide segment 64 is L t The transition section is a section with gradually changing width. The length of the second waveguide section 62 is equal to the length of the sixth waveguide section 66, which is L3 + L2 / 2, where L2 is the length calculated by the simulation software. Figure 4It can be seen that the length of the third waveguide section 63 is shorter than the length of the second waveguide section 62 .

[0046] The second waveguide arm 52 includes an eighth waveguide segment 68, a ninth waveguide segment 69, a tenth waveguide segment 70, an eleventh waveguide segment 71, a twelfth waveguide segment 72, a thirteenth waveguide segment 73, and a fourteenth waveguide segment 74, arranged in sequence. The ninth waveguide segment 69 and the thirteenth waveguide segment 73 are symmetrically arranged, and the width of the ninth waveguide segment 69 and the width of the thirteenth waveguide segment 73 are equal, both having a first width w1. The tenth waveguide segment 70 and the twelfth waveguide segment 72 are symmetrically arranged, and the width of the tenth waveguide segment 70 and the width of the twelfth waveguide segment 72 are equal, both having a second width w2. Furthermore, the eighth waveguide segment 68, the eleventh waveguide segment 71, and the fourteenth waveguide segment 74 have equal widths, all having a third width w0.

[0047] In addition, the eleventh waveguide segment 71 is in an arc shape, the length of the middle section of the twelfth waveguide segment 72 is also L3, and the length of the transition section between the twelfth waveguide segment 72 and the eleventh waveguide segment 71 is L t The transition section is a section with gradually changing width. The length of the ninth waveguide section 69 is equal to the length of the thirteenth waveguide section 73, which is L3 + L4 / 2, where L4 is the length calculated by the simulation software. Figure 4 It can be seen that the length of the ninth waveguide segment 69 is greater than that of the tenth waveguide segment 70. In addition, the length of the third waveguide segment 63 is less than that of the ninth waveguide segment 69, and the length of the second waveguide segment 62 is greater than that of the tenth waveguide segment 70.

[0048] In addition, a first thermo-optical phase shifter 53 is provided above the fourth waveguide segment 64. The first waveguide arm 51 is a waveguide formed on a silicon substrate, such as a silicon waveguide layer. The first thermo-optical phase shifter 53 is located within a silicon dioxide cladding layer above the silicon waveguide layer. Therefore, the first thermo-optical phase shifter 53 is closely attached to the fourth waveguide segment 64 of the first waveguide arm 51.

[0049] The first waveguide arm 51 of this embodiment has three different widths. The purpose of setting different widths for each waveguide segment is to adjust the group refractive index of the waveguide. In combination with the length of each waveguide segment, the free spectral range of the first waveguide arm 51 can be calculated and observed through simulation software, thereby ensuring that within the 250nm bandwidth, the free spectral range does not substantially vary with wavelength, thereby complying with the CWDM standard requirement that the spacing between adjacent wavelength channels of the demultiplexer within the 250nm bandwidth is always 20nm.

[0050] Furthermore, this embodiment only includes the first thermo-optical phase shifter 53 on the first waveguide arm 51; no thermo-optical phase shifter is provided on the second waveguide arm 52. By applying an appropriate voltage to the first thermo-optical phase shifter 53, the first and second waveguide arms 51, 52 can generate the required dual-arm phase difference required for operating in different wavelength bands, thereby achieving wavelength-based light splitting. Because this embodiment can function as a four-way coarse wavelength division (or demultiplexer) with a wavelength channel spacing of 20 nm, by adjusting the temperatures of the first and second thermo-optical phase shifters 53 and 22, this embodiment can operate within a 250 nm wavelength bandwidth within any 80 nm bandwidth, thus covering a wider bandwidth range.

[0051] Silicon-based integrated wavelength division multiplexer working method embodiment:

[0052] The following combination Figure 5 The operating method of the aforementioned silicon-based integrated wavelength division multiplexer is described below. First, step S1 is executed to obtain the current voltage value of the first thermo-optical phase shifter. Then, step S2 is executed to determine the target voltage to be applied to the first thermo-optical phase shifter based on the wavelength of the light beam to be split by the wavelength division multiplexer. Simultaneously, step S3 is executed to determine the voltage to be applied to the second thermo-optical phase shifter. Preferably, because the voltages corresponding to the operating wavelengths that the wavelength division multiplexer can split light vary at different temperatures, the voltages corresponding to the different wavelengths required at different temperatures can be pre-set. When executing steps S2 and S3, the corresponding voltages can be determined by looking up a table.

[0053] Then, step S4 is executed to apply a target voltage to the first thermo-optical phase shifter based on the voltages determined in steps S2 and S3, and a corresponding voltage is applied to the second thermo-optical phase shifter, causing the temperatures of the first and second thermo-optical phase shifters to change. Finally, step S5 is executed to sequentially input light beams containing multiple wavelengths into the first tunable optical splitter of the first-stage wavelength division multiplexing unit, and step S6 is executed to receive the split light beams from the multiple output ports. In this way, the light beam received from each output port essentially contains only a single wavelength, thereby achieving wavelength division multiplexing.

[0054] Finally, it should be emphasized that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Silicon-based integrated wavelength division multiplexer, including: At least one level of wavelength division multiplexing unit, wherein the wavelength division multiplexing unit comprises a first adjustable optical splitter, a first unbalanced arm, and a second adjustable optical splitter arranged in sequence; It is characterized by: The first unbalanced arm includes a first waveguide arm and a second waveguide arm, both of which are U-shaped. The first waveguide arm includes a first waveguide segment, a second waveguide segment, a third waveguide segment, a fourth waveguide segment, a fifth waveguide segment, a sixth waveguide segment, and a seventh waveguide segment, wherein the third waveguide segment and the fifth waveguide segment are symmetrically arranged and have a first width, and the second waveguide segment and the sixth waveguide segment are symmetrically arranged and have a second width. The second waveguide arm includes an eighth waveguide segment, a ninth waveguide segment, a tenth waveguide segment, an eleventh waveguide segment, a twelfth waveguide segment, a thirteenth waveguide segment, and a fourteenth waveguide segment arranged in sequence, wherein the ninth waveguide segment and the thirteenth waveguide segment are symmetrically arranged and have the first width, the tenth waveguide segment and the twelfth waveguide segment are symmetrically arranged and have the second width, and the first width is greater than the second width; A first thermo-optical phase shifter is covered above the fourth waveguide segment; The length of the third waveguide segment is smaller than the length of the second waveguide segment, and the length of the ninth waveguide segment is larger than the length of the tenth waveguide segment; The first adjustable optical splitter comprises a first adiabatic coupler and a second adiabatic coupler, two connecting waveguides are formed between the first adiabatic coupler and the second adiabatic coupler, and a second thermo-optical phase shifter is provided on one of the connecting waveguides; The first adiabatic coupler and the second adiabatic coupler have the same structure; The first adiabatic coupler comprises a first waveguide and a second waveguide, the first waveguide comprising a fifteenth waveguide segment, a sixteenth waveguide segment, and a seventeenth waveguide segment arranged in sequence, and the second waveguide comprising an eighteenth waveguide segment, a nineteenth waveguide segment, and a twentieth waveguide segment arranged in sequence; The sixteenth waveguide segment and the nineteenth waveguide segment are close to each other to form a coupling segment; A fourth width of a first connection point between the fifteenth waveguide segment and the sixteenth waveguide segment is smaller than a fifth width of a second connection point between the sixteenth waveguide segment and the seventeenth waveguide segment; A sixth width of a third connection point between the eighteenth waveguide segment and the nineteenth waveguide segment is greater than a seventh width of a fourth connection point between the nineteenth waveguide segment and the twentieth waveguide segment; The fifth width is equal to the seventh width.

2. The silicon-based integrated wavelength division multiplexer according to claim 1, wherein: The length of the third waveguide segment is smaller than that of the ninth waveguide segment, and the length of the second waveguide segment is larger than that of the tenth waveguide segment.

3. The silicon-based integrated wavelength division multiplexer according to claim 1, wherein: The fourth waveguide segment is in an arc shape and has a third width, and the eleventh waveguide segment is in an arc shape and has the third width; The third width is smaller than the second width.

4. The silicon-based integrated wavelength division multiplexer according to claim 1, wherein: A distance between the sixteenth waveguide segment and the nineteenth waveguide segment is smaller than the fifth width.

5. The silicon-based integrated wavelength division multiplexer according to claim 1, wherein: The length of the sixteenth waveguide segment is equal to the length of the nineteenth waveguide segment.

6. The silicon-based integrated wavelength division multiplexer according to claim 1, wherein: The coupling ratio of the first adiabatic coupler is between 0.43 and 0.63; and / or The coupling ratio of the second adiabatic coupler is between 0.43 and 0.

63.

7. A method for operating a silicon-based integrated wavelength division multiplexer, applied to the silicon-based integrated wavelength division multiplexer according to any one of claims 1 to 6, characterized in that: include: Obtaining a current voltage value of the first thermo-optical phase shifter, and determining a target voltage to be applied to the first thermo-optical phase shifter according to a target wavelength to be split by the silicon-based integrated wavelength division multiplexer; applying the target voltage to the first thermo-optical phase shifter so that the temperature of the first thermo-optical phase shifter changes; A light beam containing at least two different wavelengths is sequentially input to the first adjustable beam splitter, and the first adjustable beam splitter, the first unbalanced arm and the second adjustable beam splitter are used to split the input light beam according to wavelength.

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