Wavelength division multiplexer, wavelength division demultiplexer and wavelength division multiplexing device

Abstract

The utility model provides a wavelength division multiplexer, a wavelength division demultiplexer and a wavelength division multiplexing device. The wavelength division multiplexer comprises a substrate layer and a multiplexing layer, the multiplexing layer is provided with at least two coupling areas, the coupling areas are used for coupling optical signals with preset wavelengths from a free space, the coupling areas are provided with metasurface microstructure units, the diameter of each metasurface microstructure unit is smaller than 1 / 2 of the corresponding preset wavelength, and the height of each metasurface microstructure unit is smaller than the corresponding preset wavelength; the multiplexing layer is provided with an output waveguide and wave combining waveguides corresponding to the coupling areas in number, one end of each wave combining waveguide is connected to the corresponding coupling area, and the other end of each wave combining waveguide is connected to the output waveguide; the optical signal emission unit is arranged on one side of the substrate layer. According to the scheme, the laser light source does not need to be collimated, the laser light source directly irradiates the metasurface area of the corresponding coupling area to realize coupling of optical signals with corresponding wavelengths, the structure is simple, the scheme cost of the coupling device can be greatly reduced, coupling steps and precision requirements are reduced, and the processing cost of the device is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of optical communication technology, and in particular relates to a wavelength division multiplexer, a wavelength demultiplexer, and a wavelength division multiplexing device. Background Art

[0002] To achieve higher communication bandwidth, WDM (Wavelength Division Multiplexing) technology couples optical signals of multiple wavelengths into the same optical fiber for propagation. This often requires a complex optical path system. For example, patent JP3235068U uses multiple lenses and filters to couple different wavelengths of laser light into a single path. However, this method requires extremely high assembly and alignment precision, with each optical path requiring precise adjustment and assembly. Another example is patent CN105425338A, which requires a complex combination of prisms and filters to achieve WDM / demultiplexing functionality. This also typically requires extremely high manufacturing precision and multiple coupling processes with the light source, detector, and collimating lens, making the process cumbersome. Yet another example is patent CN220019930U, which uses a metasurface method to achieve wavelength multiplexing, but still faces alignment and coupling challenges with the optical fiber, collimating lens, and focusing lens.

[0003] It is evident that existing wavelength division multiplexing (WDM) devices suffer from technical challenges such as complex structures and high precision requirements. Utility Model Content

[0004] The technical objective of this invention is to provide a wavelength division multiplexer, a wavelength division demultiplexer, and a wavelength division multiplexing device. The structure is simple, which can greatly reduce the cost of CWDM solutions, reduce coupling steps and accuracy requirements, and significantly reduce device and processing costs.

[0005] To solve the above-mentioned technical problems, this utility model provides a wavelength division multiplexer, including a substrate layer and a multiplexing layer located on one side of the substrate layer; the multiplexing layer is provided with at least two coupling regions, which are used to couple optical signals of a preset wavelength from free space. Each coupling region is provided with metasurface microstructure units arranged at intervals, the diameter of each metasurface microstructure unit being less than 1 / 2 of the corresponding preset wavelength, and the height being less than the corresponding preset wavelength; the multiplexing layer is provided with an output waveguide and a multiplexing waveguide corresponding to the number of coupling regions, one end of each multiplexing waveguide being connected to each coupling region, and the other end of each multiplexing waveguide being connected to the output waveguide.

[0006] Furthermore, the height of the metasurface microstructure unit is 400nm to 1800nm, and the diameter is 100nm to 600nm.

[0007] Furthermore, within the same coupling region, the metasurface microstructure units are uniformly arranged, and the spacing between adjacent metasurface microstructure units is less than 2 / 3 of the corresponding preset wavelength.

[0008] Furthermore, the spacing between adjacent metasurface microstructure units is less than 1 / 2 of the corresponding preset wavelength.

[0009] Furthermore, the metasurface microstructure unit is made of silicon material, the reuse layer is made of SiO2 or TiO2 material, and the metasurface microstructure unit of the coupling region is filled and covered by the SiO2 or TiO2 material of the reuse layer.

[0010] Furthermore, a wave demultiplexer is provided, comprising a substrate layer and an emission layer located on one side of the substrate layer; the emission layer is provided with an input waveguide, a decoupling module connected to one end of the input waveguide, and at least two waveguides connected to the decoupling module; the emission layer is provided with the same number of emission regions as the waveguides, and the other end of each waveguide is connected to each emission region in a corresponding manner; the emission regions are used to transmit optical signals of a preset wavelength in the corresponding waveguides into free space; the emission regions are provided with metasurface microstructure units arranged at intervals, the diameter of each metasurface microstructure unit being less than 1 / 2 of the corresponding preset wavelength, and the height being less than the corresponding preset wavelength.

[0011] Furthermore, the height of the metasurface microstructure unit is 400nm to 1800nm, and the diameter is 100nm to 600nm.

[0012] Furthermore, within the same emission region, the metasurface microstructure units are uniformly arranged, and the spacing between adjacent metasurface microstructure units is less than 2 / 3 of the corresponding preset wavelength.

[0013] Furthermore, the metasurface microstructure unit is made of silicon material, the emission layer is made of SiO2 material, and the metasurface microstructure unit of the emission region is filled and covered by the SiO2 material of the emission layer.

[0014] Furthermore, a wavelength division multiplexing device is provided, including an optical signal transmitting unit, a photoelectric converter, a wavelength division multiplexer as described in any one of the above claims, and a wavelength demultiplexer as described in any one of the above claims. The optical signal transmitting unit is disposed on the side of the transmitting region away from the substrate layer, and the photoelectric converter is disposed on the side of the transmitting region away from the substrate layer.

[0015] Compared with the prior art, the wavelength division multiplexer, wavelength division demultiplexer, and wavelength division multiplexing device of this utility model have the following advantages:

[0016] The multiplexing layer has multiple coupling regions, and each coupling region contains a metasurface microstructure unit matched to a corresponding preset wavelength optical signal. Thus, optical signals of the corresponding wavelength in free space can be coupled to the corresponding waveguide through the coupling regions. Different wavelength optical signals transmitted through each waveguide are ultimately combined in the output waveguide, resulting in a wavelength-multiplexed optical signal. This eliminates the need for laser source collimation; the laser source can directly illuminate the corresponding coupling region to achieve the coupling of the optical signal of the corresponding wavelength. The structure is simpler, significantly reducing the cost of the coupling device, simplifying coupling steps and accuracy requirements, and lowering device fabrication costs. Attached Figure Description

[0017] Figure 1a This is a top view of the structural layout of the wavelength division multiplexer in this embodiment of the present invention;

[0018] Figure 1b This is a schematic diagram of the structural layout of the wavelength division multiplexer in the main view of an embodiment of this utility model;

[0019] Figure 2a This is a top view of the structural layout of the wave demultiplexer in this embodiment of the present invention;

[0020] Figure 2b This is a schematic diagram of the structural layout of the wave demultiplexer in the main view of an embodiment of this utility model;

[0021] Figure 3 This is a schematic diagram of the arrangement of metasurface microstructure units in some implementations of this utility model.

[0022] In the accompanying drawings, the reference numerals represent: 10, wavelength division multiplexer; 110, substrate layer; 120, multiplexing layer; 130, coupling region; 1201, multiplexing waveguide; 1202, output waveguide; 20, wavelength division multiplexer; 210, substrate layer; 220, transmitting layer; 230, transmitting region; 240, decoupling module; 2201, wavelength division waveguide; 2202, input waveguide; 30, optical signal transmitting unit; 40, photoelectric converter. DETAILED DESCRIPTION

[0023] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0024] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] In this embodiment, referring to Figures 1-2, a wavelength division multiplexing device is provided, including an optical signal transmitting unit 30, a photoelectric converter 40, a wavelength division multiplexer 10, and a wavelength demultiplexer 20.

[0027] Among them, such as Figure 1a and Figure 1b The wavelength division multiplexer 10 includes a substrate 110 and a multiplexing layer 120 located on one side of the substrate 110. The multiplexing layer 120 is provided with at least two coupling regions 130. The coupling regions 130 are used to couple optical signals of a preset wavelength from free space. The coupling regions 130 are provided with metasurface microstructure units arranged at intervals. The diameter of each metasurface microstructure unit is less than 1 / 2 of the corresponding preset wavelength, and the height is less than the corresponding preset wavelength. The multiplexing layer 120 is provided with an output waveguide 1202 and a multiplexing waveguide 1201 corresponding to the number of coupling regions 130. One end of each multiplexing waveguide 1201 is connected to each coupling region 130, and the other end of each multiplexing waveguide 1201 is connected to the output waveguide 1202. The optical signal transmitting unit 30 is disposed on the side of the coupling region 130 away from the substrate 110.

[0028] The preset wavelength range is between 400-1800nm, and the preset wavelength of each coupling region 130 is preferably different. Common wavelengths can be 850nm, 905nm, 940nm, 1310nm, 1550nm, etc. Multiple coupling regions 130 are provided on the multiplexing layer 120. The distance between adjacent coupling regions 130 is greater than 0.125mm, usually 0.25mm, 0.35mm or 0.5mm. Metasurface microstructure units matching the optical signal of the corresponding preset wavelength are provided on the coupling region 130. In this way, the optical signal of the corresponding wavelength in free space can be coupled to the corresponding waveguide 1201 through the coupling region 130. The different wavelength optical signals transmitted by each waveguide 1201 are finally combined in the output waveguide 1202. After wave combination, the wavelength multiplexed optical signal can be output. Thus, without the need to collimate the laser source, the laser source can directly irradiate the corresponding coupling region 130 metasurface area to achieve the coupling of the corresponding wavelength optical signal. The structure is simpler, which can greatly reduce the cost of the coupling device, reduce coupling steps and accuracy requirements, and reduce the device processing cost.

[0029] like Figure 2a and Figure 2b The wave demultiplexer 20 includes a substrate 210 and a transmitter 220 located on one side of the substrate 210. The transmitter 220 has an input waveguide 2202, a decoupling module 240 connected to one end of the input waveguide 2202, and at least two wave demultiplexers 2201 connected to the decoupling module 240. The transmitter 220 has the same number of transmitter regions 230 as the number of wave demultiplexers 2201. The other end of each wave demultiplexer 2201 is connected to each transmitter region 230 in a corresponding manner. Adjacent transmitter regions 230... The spacing between the 30s is greater than 0.125mm, typically 0.25mm, 0.35mm or 0.5mm. The emitting region 230 is used to transmit the optical signal of the preset wavelength in the corresponding waveguide 2201 into free space. The emitting region 230 is provided with metasurface microstructure units arranged at intervals. The diameter of each metasurface microstructure unit is less than 1 / 2 of the corresponding preset wavelength, and the height is less than the corresponding preset wavelength. The photoelectric converter 40 is disposed on the side of the emitting region 230 away from the substrate layer 210110.

[0030] The decoupling module 240 can be a CMZ (Cascaded Mach-Zehnder demultiplexer). After the composite light in the input waveguide 2202 passes through the decoupling module 240, the light signals of different wavelengths are split into the corresponding waveguides 2201, and then transmitted to the corresponding emission region 230 through the waveguides 2201. Finally, the light signal is modulated and emitted into free space and focused by the metasurface microstructure unit in the corresponding emission region 230.

[0031] In this embodiment, the optical signal transmitting unit 30 can be a DFB (Distributed Feedback) laser source or a VCSEL (Vertical Cavity Surface Emitting) laser source. The number of optical signal transmitting units 30 can be adaptively set according to the number of coupling regions 130 on the wavelength division multiplexer 10, preferably equal in number. Furthermore, the optical signal transmitting units 30 and their corresponding coupling regions 130 are preferably arranged facing each other, and the emitted laser wavelength matches the preset wavelength of the coupling region 130. Thus, the optical signal of the corresponding wavelength can be coupled more efficiently into the waveguide 1201 through the coupling region 130. It should be understood that in some embodiments, the coupling regions 130 can be concentrated in one area, and the emission range of each optical signal transmitting unit 30 covers this area. That is, the laser emitted by each optical signal transmitting unit 30 can illuminate all coupling regions 130. The coupling regions 130 can couple the wavelength-matched optical signals. In this way, the setting angle and direction of the optical signal transmitting units 30 are more flexible, without needing to meet overly stringent precision requirements. The structure of the wavelength division multiplexer 10 can be simpler, and the structural freedom is higher.

[0032] In this embodiment, the photoelectric converter 40 can be a PD photoelectric converter 40, which is used to convert optical signals into electrical signals. Similar to the optical signal transmitting unit 30, its number can be adaptively set according to the number of transmitting regions 230 on the wavelength demultiplexer 20. Preferably, the number is equal. Each transmitting region 230 is provided with a photoelectric converter 40 at its focal point, thereby converting optical signals of different wavelengths into electrical signals, realizing the conversion and transmission of electrical signals after optical wavelength demultiplexing.

[0033] In a wavelength division multiplexing (WDM) device, the WDM multiplexer 10 and the WDM demultiplexer 20 can be connected via an optical fiber link between the output waveguide 1202 and the input waveguide 2202. In this case, the WDM multiplexer 10 and the WDM demultiplexer 20 can function as two separable components. In some embodiments, the WDM multiplexer 10 and the WDM demultiplexer 20 can be integrated into a single chip as a whole. In this case, the input waveguide 2202 and the output waveguide 1202 can be directly connected, and the WDM multiplexer 10 and the WDM demultiplexer 20 can share a common substrate layer. It should be understood that the form of the WDM multiplexer 10 and the WDM demultiplexer 20 can be adapted to specific circumstances, and the foregoing exemplary description is not intended to limit the scope of protection of this application.

[0034] In the aforementioned wavelength division multiplexer 10 and wavelength demultiplexer 20, the height of the metasurface microstructure unit is 400nm to 1800nm, such as 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm, 950nm, 1000nm, 1050nm, 1100nm, 1150nm, etc., and the diameter is 100nm to 600nm, such as 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, etc. It should be understood that the height and diameter are only required to be within the aforementioned range and are not limited to the listed dimensions. Within the same coupling region 130 or emission region 230, metasurface microstructure units are uniformly arranged, and the spacing between adjacent metasurface microstructure units is less than 2 / 3 of the corresponding preset wavelength; preferably, the spacing between adjacent metasurface microstructure units is less than 1 / 2 of the corresponding preset wavelength. The metasurface microstructure units are preferably cylindrical. However, in some embodiments, the metasurface microstructure units can also be square pillars, cuboid structures, prism structures, etc., as long as the aforementioned dimensional conditions are met.

[0035] In the wavelength division multiplexer 10 and wavelength demultiplexer 20 described above, the metasurface microstructure units can be made of silicon, the substrate layer 110 can be made of Si, the multiplexing layer 120 can be made of SiO2, and the waveguide can be made of either Si or SiO2. The metasurface microstructure units in the coupling region 130 can be filled and covered by the SiO2 material of the multiplexing layer 120 or left uncovered. When covered by SiO2, the metasurface microstructure units are protected, resulting in higher reliability. In all the aforementioned structural materials, SiO2 can be replaced by TiO2.

[0036] It should be understood that the coupling region 130 of wavelength division multiplexer 10 and the transmission region 230 of wavelength division demultiplexer 20 have basically the same structure and parameters. The difference between wavelength division multiplexer 10 and wavelength division demultiplexer 20 is that a decoupling module 240 is set between the input waveguide 2202 and the demultiplexer waveguide 2201 of wavelength division demultiplexer 20.

[0037] Below are some specific examples of metasurface structure units for wavelength division multiplexer 10 and wavelength demultiplexer 20. It should be noted that the structural settings of coupling region 130 of wavelength division multiplexer 10 and emission region 230 of wavelength demultiplexer 20 are one-to-one corresponding, so they will not be elaborated on separately.

[0038] Example 1:

[0039] In a coupling region 130 (emission region 230), corresponding to a wavelength of 940nm, the metasurface microstructure units are arranged in a square array, that is, arranged at equal intervals in the horizontal and vertical directions, in a cylindrical shape, with a column height of 700nm, a column spacing of 340nm, and a column diameter between 100-350nm, such as 150nm, 250nm, etc., so that the optical signal with a wavelength of 940nm can be coupled (emitted).

[0040] Example 2:

[0041] In a coupling region 130 (emission region 230), corresponding to a wavelength of 1090nm, the metasurface microstructure units are arranged in a square array, that is, arranged at equal intervals in the horizontal and vertical directions, in a cylindrical shape. The column height is selected as 900nm, the column spacing is 400nm, and the column diameter can be between 200-500nm, such as 250nm, 350nm, 450nm, etc. In this way, optical signals with a wavelength of 1090nm can be coupled (emitted).

[0042] Example 3:

[0043] In a coupling region 130 (emission region 230), corresponding to a wavelength of 1440nm, the metasurface microstructure units are arranged in a square array, that is, arranged at equal intervals in the horizontal and vertical directions, in a cylindrical shape. The column height is selected as 1300nm, the column spacing is 650nm, and the column diameter can be between 500-700nm, such as 500nm, 550nm, 650nm, etc. In this way, optical signals with a wavelength of 1440nm can be coupled (emitted).

[0044] In some implementations, the metasurface microstructure units can be cylindrical or rectangular; these units can be arranged in a square array or an alternating array, for example... Figure 3 The example illustrates the morphology and arrangement of the concentrated microstructure units. As long as each metasurface microstructure unit is uniformly arranged and meets the aforementioned conditions and the preset wavelength matching, it is acceptable.

[0045] The above examples are merely illustrative and are not intended to limit the scope of protection of this application. It should be understood that, based on the concept of this application, those skilled in the art can adaptively adjust the parameters of the metasurface microstructure units to suit the coupling or emission of optical signals of different wavelengths.

[0046] In this application, both the wavelength division multiplexer 10 and the wavelength demultiplexer 20 can be fabricated using CMOS (Complementary Metal-Oxide-Semiconductor) technology, integrating multiple functions onto a single chip to achieve wavelength division multiplexing in CWDM. Metasurface optical design is used to couple and convert free-space light and waveguide light fields, and waveguide structure design enables the combining and splitting of light of different wavelengths. This solves the problem of traditional CWDM requiring multiple optical elements for alignment and coupling. Furthermore, by integrating multiple functions onto a single chip, this invention significantly reduces device costs.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A wavelength division multiplexer, characterized in that, The system includes a substrate layer and a multiplexing layer located on one side of the substrate layer. The multiplexing layer has at least two coupling regions, which are used to couple optical signals of a preset wavelength from free space. Each coupling region has a metasurface microstructure unit arranged at intervals, and the diameter of each metasurface microstructure unit is less than 1 / 2 of the corresponding preset wavelength, and the height is less than the corresponding preset wavelength. The multiplexing layer has an output waveguide and a wave combiner waveguide corresponding to the number of coupling regions. One end of each wave combiner waveguide is connected to each of the coupling regions, and the other end of each wave combiner waveguide is connected to the output waveguide.

2. The wavelength division multiplexer according to claim 1, characterized in that, The height of the metasurface microstructure unit is 400nm to 1800nm, and the diameter is 100nm to 600nm.

3. The wavelength division multiplexer according to claim 2, characterized in that, Within the same coupling region, the metasurface microstructure units are uniformly arranged, and the spacing between adjacent metasurface microstructure units is less than 2 / 3 of the corresponding preset wavelength.

4. The wavelength division multiplexer according to claim 3, characterized in that, The spacing between adjacent metasurface microstructure units is less than 1 / 2 of the corresponding preset wavelength.

5. The wavelength division multiplexer according to claim 4, characterized in that, The metasurface microstructure unit is made of silicon material, the reuse layer is made of SiO2 or TiO2 material, and the metasurface microstructure unit of the coupling region is filled and covered by the SiO2 or TiO2 material of the reuse layer.

6. A wave demultiplexer, characterized in that, The system includes a substrate layer and an emission layer located on one side of the substrate layer. The emission layer has an input waveguide, a decoupling module connected to one end of the input waveguide, and at least two waveguides connected to the decoupling module. The emission layer has the same number of emission regions as the waveguides. The other end of each waveguide is connected to each emission region. The emission regions are used to transmit optical signals of a preset wavelength in the corresponding waveguides into free space. The emission regions have metasurface microstructure units arranged at intervals. The diameter of each metasurface microstructure unit is less than 1 / 2 of the corresponding preset wavelength, and the height is less than the corresponding preset wavelength.

7. The wave demultiplexer according to claim 6, characterized in that, The height of the metasurface microstructure unit is 400nm to 1800nm, and the diameter is 100nm to 600nm.

8. The wave demultiplexer according to claim 7, characterized in that, Within the same emission region, the metasurface microstructure units are uniformly arranged, and the spacing between adjacent metasurface microstructure units is less than 2 / 3 of the corresponding preset wavelength.

9. The wave demultiplexer according to claim 6, characterized in that, The metasurface microstructure unit is made of silicon material, the emission layer is made of SiO2 material, and the metasurface microstructure unit of the emission region is filled and covered by the SiO2 material of the emission layer.

10. A wavelength division multiplexing device, characterized in that, The device includes an optical signal transmitting unit, a photoelectric converter, a wavelength division multiplexer as described in any one of claims 1-5, and a wavelength division demultiplexer as described in any one of claims 6-9. The optical signal transmitting unit is disposed on the side of the transmitting region away from the substrate layer, and the photoelectric converter is disposed on the side of the transmitting region away from the substrate layer.

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