An interleaved large-channel wavelength division multiplexer

Abstract

The present invention relates to a large-channel wavelength division multiplexer based on an interleaved structure. The present invention includes, from bottom to top, a substrate of a wafer, a buried oxide layer of the wafer, a device layer, and a SiO2 upper cladding of the device. The device layer includes a microring resonator, a phase shifter, a transmission waveguide, and an arrayed waveguide grating respectively. The phase shifter is loaded on the microring. The microring resonator is connected to two arrayed waveguide gratings above and below through the transmission waveguide. In the present invention, two waveguide array gratings with interleaved output channel wave peaks are cascaded by the microring resonator. The resonant wave peak of the direct-through end of the microring coincides with the output wave peaks of each channel of the lower arrayed waveguide grating, and the resonant wave peak of the downloaded end of the microring resonator coincides with the output wave peaks of each channel of the upper arrayed waveguide grating. Moreover, the output wave peaks of the upper arrayed waveguide grating and the lower arrayed waveguide grating are arranged in an interleaved manner, thereby forming a large-channel wavelength division multiplexer with interleaved channels. The present invention solves the problem of fewer wavelength channels in a conventional wavelength division multiplexer and performs well in terms of low crosstalk.

Description

Technical Field

[0001] The present invention relates to a large-channel wavelength division multiplexer based on an interleaved structure, belonging to the technical field of semiconductor optical signal transmission. Background Art

[0002] Optical fiber communication is a communication method that uses light waves as carriers and optical fibers as transmission media, carrying more than 90% of the global communication data capacity. The greatest advantage of the optical network lies in the wavelength division multiplexing technology, which has the transmission capabilities of high speed and large capacity. Its technological progress has greatly promoted the development of optical fiber communication and brought a revolutionary change to the transmission technology. Silicon-based photonic devices based on materials have extremely small sizes and low costs. Their manufacturing processes are fully compatible with the COMS process and can be monolithically integrated with IC circuits. With this unique advantage, they have become one of the hotspots in the field of optical fiber communication research. Currently, there are mainly four structures for wavelength division multiplexers in silicon photonics: etched gratings (EDG), micro-ring resonators (Micro-Ring Resonator, MRR), cascaded MZIs, and silicon arrayed waveguide gratings (Silicon arrayed waveguide grating, Silicon AWG). Etched gratings are suitable for coarse multiplexing and cannot achieve dense wavelength division multiplexing, so their scope of application is somewhat limited. Micro-ring resonators achieve demultiplexing by cascading micro-rings with different radii and using the resonant wavelength. Affected by the process, it is difficult to control a stable wavelength interval, and a tuning system needs to be added. Multiple tuning systems will cause relatively large additional power consumption. MZIs achieve wavelength division multiplexing through the difference in arm lengths. When the number of channels increases, the number of cascades also increases, and the chip size increases, which is not conducive to integration. For the above reasons, these three silicon-based photonic devices have not been widely used in the field of wavelength division multiplexing. The silicon-based photonic arrayed waveguide grating is a wavelength division multiplexing / demultiplexing device with the most excellent comprehensive performance. Since the birth of the arrayed waveguide grating AWG, it has been widely studied because it is more compact than MRR and MZI, and has lower insertion loss and better crosstalk performance. It has been reported that a 16-channel AWG based on silicon nitride has been developed, which can achieve -30 dB of adjacent-channel crosstalk at a loss of 0.5 dB. However, due to the low refractive index difference, the floor area of the entire device exceeds 1 square centimeter. Based on the high refractive index contrast characteristic of silicon, a compact AWG with a floor area of 400×600 μm2 has been designed. However, the crosstalk between adjacent channels is as high as 10 dB. In addition, some novel design schemes have been proposed, such as a folded structure. For example, reflectors are added to the arrayed waveguide to form a 4-channel folded AWG, and the crosstalk and insertion loss are approximately -20 dB and 3.5 dB respectively, and the results are not very satisfactory. Therefore, how to achieve a multi-channel high-performance AWG in a compact occupied space remains a challenge. Summary of the Invention

[0003] In view of the problems and deficiencies of the above-mentioned existing technologies, the present invention provides a large-channel wavelength division multiplexer based on an interleaved structure, which can solve the problems of large channel crosstalk in large-channel wavelength division multiplexers and the problem of fewer wavelength channels in conventional wavelength division multiplexers.

[0004] The technical solution of the present invention is: a large-channel wavelength division multiplexer based on an interleaved structure, which includes, from bottom to top, a substrate of a wafer, a buried oxide layer of the wafer, a device layer, and a SiO2 upper cladding of the device. The device layer includes a microring resonator 110, a phase shifter 120, a download waveguide 130, a through waveguide 140, an upper arrayed waveguide grating 150, and a lower arrayed waveguide grating 160. The phase shifter 120 is loaded on the microring resonator (110). The download end of the microring resonator 110 is connected to the upper arrayed waveguide grating (150) through the download waveguide 130, and the through end of the microring resonator (110) is connected to the lower arrayed waveguide grating 160 through the through waveguide 140.

[0005] As a further solution of the present invention, the microring resonator 110 includes an output straight waveguide 111, a ring resonator cavity 112, and an input straight waveguide 113. There is a first coupling region 5 between the output straight waveguide 111 and the ring resonator cavity 112 located below the output straight waveguide 111. There is a second coupling region 6 between the input straight waveguide 113 and the ring resonator cavity 112 located above the input straight waveguide 113. The phase shifter 120 is a device for connecting a power supply to adjust the resonance wavelength of the microring and acts on the ring resonator cavity 112.

[0006] As a further solution of the present invention, the output straight waveguide 111 is divided into an output straight waveguide download end 1 and an output straight waveguide output end 2, and the input straight waveguide 113 is divided into an input straight waveguide input end 3 and an input straight waveguide through end 4.

[0007] As a further solution of the present invention, the download waveguide 130 includes a semi-circular bent waveguide and a straight waveguide. The output straight waveguide download end 1 is connected to the upper input waveguide 8 of the upper arrayed waveguide grating 150 through the download waveguide 130.

[0008] As a further solution of the present invention, the through waveguide 140 includes an S-shaped bent waveguide and a straight waveguide. The input straight waveguide through end 4 of the microring resonator 110 is connected to the lower input waveguide 13 of the lower arrayed waveguide grating 160 through the through waveguide 140.

[0009] As a further aspect of the present invention, the upper arrayed waveguide grating 150 includes an upper input waveguide 8, an upper input slab waveguide 9, an upper arrayed waveguide 10, an upper output slab waveguide 11, and an upper output waveguide 12; the upper input waveguide 8 is connected to the upper input slab waveguide 9; the upper input slab waveguide 9 is connected to the upper output slab waveguide 11 through the upper arrayed waveguide 10. The upper input slab waveguide 9, the upper arrayed waveguide 10, and the upper output slab waveguide 11 form a Rowland circle structure, and the upper output slab waveguide 11 is connected to the upper output waveguide 12.

[0010] As a further aspect of the present invention, the lower arrayed waveguide grating 160 includes a lower input waveguide 13, a lower input slab waveguide 14, a lower arrayed waveguide 15, a lower output slab waveguide 16, and a lower output waveguide 17; the lower input waveguide 13 is connected to the lower input slab waveguide 14; the lower input slab waveguide 14 is connected to the lower output slab waveguide 16 through the lower arrayed waveguide 15. The lower input slab waveguide 14, the lower arrayed waveguide 15, and the lower output slab waveguide 16 form a Rowland circle structure, and the lower output slab waveguide 16 is connected to the lower output waveguide 17.

[0011] As a further aspect of the present invention, the free spectral range FSR of the microring resonator 110 is equal to the channel spacing of the upper arrayed waveguide grating 150 and also equal to the channel spacing of the lower arrayed waveguide grating 160.

[0012] As a further aspect of the present invention, there is a central wavelength difference of Δλ between the central wavelengths of the upper arrayed waveguide grating 150 and the lower arrayed waveguide grating 160, and the free spectral range FSR of the microring resonator 110 is equal to 2Δλ, where Δλ represents the channel spacing of the upper arrayed waveguide grating 150 and the channel spacing of the lower arrayed waveguide grating 160 is also Δλ.

[0013] As a further aspect of the present invention, the resonant peaks at the download end of the microring resonator 110 coincide with the peak wavelengths of the channels of the upper arrayed waveguide grating 150, and the resonant peaks at the through end of the microring resonator 110 coincide with the peak wavelengths of the channels of the lower arrayed waveguide grating 160.

[0014] The working principle of the present invention is as follows: Through the modulation of the phase shifter 120 loaded on the microring resonator 110, the refractive index of the waveguide of the microring resonator filter is changed by the thermo-optic / electro-optic effect, so as to adjust the resonant central wavelength of the microring resonator 110, making the resonant peak at the download end of the microring match the output peak of the upper arrayed waveguide grating 150 (AWG) (such as Figure 5 ), and at the same time, the resonant peak at the through end of the microring coincides with the output peak of the lower arrayed waveguide grating 160 (AWG) (such as Figure 6)。In the actual working environment, an optical signal is input from the straight waveguide under the micro-ring. A part of the light is coupled into the ring resonator 112 through the straight waveguide. After passing through a path of half a circumference, the wavelength signal that generates the resonance effect is coupled into the output straight waveguide 111 from the first coupling region 5 of the micro-ring resonator, and is output from its download end. After passing through a section of curved waveguide, it enters the upper arrayed waveguide grating 150. Another part of the light is coupled into the ring resonator 112 through the straight waveguide again. After passing through a path of one circumference, a phase change occurs, and it is coupled into the input straight waveguide 113 from the second coupling region 6 of the micro-ring resonator to interfere with the optical signal of the original lower input straight waveguide. The interfered optical signal is output from the through end 4 of the input straight waveguide and enters the lower arrayed waveguide grating 160 after passing through a section of curved waveguide. The arrayed waveguide grating AWG is composed of strip waveguides and arrayed waveguides. As the length of the arrayed waveguides in the arrayed waveguide grating AWG increases linearly, the phase change caused by the wavelength change varies linearly along the output aperture. Therefore, the focus of the light moves along the output surface of the second planar waveguide. By placing the output waveguide in an appropriate position, spatial separation of different wavelength channels can be obtained. In the present invention, the output waveguide positions of the upper and lower arrayed waveguide gratings AWG are staggered. The micro-ring resonator 110 functions as a filter and wavelength demultiplexer. The resonant peaks output from the download end of the micro-ring resonator 110 coincide with the channel peaks of the upper arrayed waveguide grating 150, and the resonant peaks output from the through end of the micro-ring resonator 110 coincide with the channel peaks of the lower arrayed waveguide grating 160. The resonant peaks after the two arrayed waveguide gratings are superimposed through the micro-ring resonator 110 are staggered in the spectrogram, as Figure 7 , and the free spectral range FSR of the arrayed waveguide grating after staggering > n·△λ. Compared with the conventional arrayed waveguide grating AWG, it can achieve twice the number of channels and is a novel large-channel wavelength division multiplexer.

[0015] The beneficial effects of the present invention are as follows: By cascading the micro-ring resonator with two waveguide array gratings with staggered output channel peaks, the resonant peaks at the through end of the micro-ring coincide with the output channel peaks of each channel of the lower arrayed waveguide grating (AWG), the resonant peaks at the download end of the micro-ring resonator coincide with the output channel peaks of each channel of the upper arrayed waveguide grating (AWG), and the output peaks of the upper arrayed waveguide grating (AWG) and the lower arrayed waveguide grating (AWG) are staggered, thereby forming a large-channel wavelength division multiplexer with staggered channels. It is a new large-channel wavelength division multiplexing scheme, which solves the problem of fewer wavelength channels in the conventional wavelength division multiplexer and performs well in terms of low crosstalk. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic connection diagram of the large-channel wavelength division multiplexer of the present invention;

[0017] Figure 2 is a schematic structural diagram of the micro-ring resonator of the present invention;

[0018] Figure 3 is a schematic diagram of the arrayed waveguide grating structure of the present invention;

[0019] Figure 4 is a schematic diagram of the arrayed waveguide grating structure of the present invention below;

[0020] Figure 5 is a matching diagram of the resonant peak at the download end of the micro - ring and the channel peak of the upper arrayed waveguide grating of the present invention;

[0021] Figure 6 is a matching diagram of the resonant peak at the through - end of the micro - ring and the channel peak of the lower arrayed waveguide grating of the present invention;

[0022] Figure 7 is an interleaved diagram of the channel peaks of the upper arrayed waveguide grating and the lower arrayed waveguide grating of the present invention.

[0023] Each label in the figure: 1 - download end of the output straight waveguide, 2 - output end of the output straight waveguide, 3 - input end of the input straight waveguide, 4 - through - end of the input straight waveguide, 5 - first coupling region, 6 - second coupling region, 8 - upper input waveguide, 9 - upper input slab waveguide, 10 - upper arrayed waveguide, 11 - upper output slab waveguide, 12 - upper output waveguide, 13 - lower input waveguide, 14 - lower input slab waveguide, 15 - lower arrayed waveguide, 16 - lower output slab waveguide, 17 - lower output waveguide, 110 - micro - ring resonator, 120 - phase shifter, 130 - download - end waveguide, 140 - through - end waveguide, 150 - upper arrayed waveguide grating, 160 - lower arrayed waveguide grating, 111 - output straight waveguide, 112 - ring resonator cavity, 113 - input straight waveguide. Detailed implementation manners

[0024] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0025] Embodiment 1: As Figures 1 - 7 shown, a large - channel wavelength division multiplexer based on an interleaved structure includes, from bottom to top, a substrate of a wafer, a buried oxide layer of the wafer, a device layer, and a SiO2 upper cladding of the device. The material of the device layer is single - crystal silicon. The device layer includes a micro - ring resonator 110, a phase shifter 120, a download - end waveguide 130, a through - end waveguide 140, an upper arrayed waveguide grating 150, and a lower arrayed waveguide grating 160; the phase shifter 120 is loaded on the micro - ring resonator (110). The download end of the micro - ring resonator 110 is connected to the upper arrayed waveguide grating (150) through the download - end waveguide 130, and the through - end of the micro - ring resonator (110) is connected to the lower arrayed waveguide grating 160 through the through - end waveguide 140.

[0026] Among them, the microring resonator 110 includes an output straight waveguide 111, a ring resonator 112, and an input straight waveguide 113; the output straight waveguide 111 is divided into an output straight waveguide download end 1 and an output straight waveguide output end 2, and the input straight waveguide 113 is divided into an input straight waveguide input end 3 and an input straight waveguide through end 4. There is a first coupling region 5 between the output straight waveguide 111 and the ring resonator 112 located below the output straight waveguide 111, and there is a second coupling region 6 between the input straight waveguide 113 and the ring resonator 112 located above the input straight waveguide 113. The phase shifter 120 is a device that connects a power supply to adjust the microring resonance wavelength and acts on the ring resonator 112.

[0027] The download end waveguide 130 includes a semicircular bent waveguide and a straight waveguide, and the output straight waveguide download end 1 is connected to the upper input waveguide 8 of the upper arrayed waveguide grating 150 through the download end waveguide 130. The through end waveguide 140 includes an S-shaped bent waveguide and a straight waveguide, and the input straight waveguide through end 4 of the microring resonator 110 is connected to the lower input waveguide 13 of the lower arrayed waveguide grating 160 through the through end waveguide 140. The upper arrayed waveguide grating 150 includes an upper input waveguide 8, an upper input slab waveguide 9, upper arrayed waveguides 10, an upper output slab waveguide 11, and an upper output waveguide 12; the upper input waveguide 8 is connected to the upper input slab waveguide 9; the upper input slab waveguide 9 is connected to the upper output slab waveguide 11 through the upper arrayed waveguides 10. The upper input slab waveguide 9, the upper arrayed waveguides 10, and the upper output slab waveguide 11 form a Rowland circle structure, and the upper output slab waveguide 11 is connected to the upper output waveguide 12. The lower arrayed waveguide grating 160 includes a lower input waveguide 13, a lower input slab waveguide 14, lower arrayed waveguides 15, a lower output slab waveguide 16, and a lower output waveguide 17; the lower input waveguide 13 is connected to the lower input slab waveguide 14; the lower input slab waveguide 14 is connected to the lower output slab waveguide 16 through the lower arrayed waveguides 15. The lower input slab waveguide 14, the lower arrayed waveguides 15, and the lower output slab waveguide 16 form a Rowland circle structure, and the lower output slab waveguide 16 is connected to the lower output waveguide 17. The free spectral range FSR of the microring resonator 110 is equal to the channel spacing △λ of the upper arrayed waveguide grating 150 and is also equal to the channel spacing △λ of the lower arrayed waveguide grating 160. There is a central wavelength difference of △λ between the central wavelengths of the upper arrayed waveguide grating 150 and the lower arrayed waveguide grating 160, and the free spectral range FSR of the microring resonator 110 is equal to 2△λ. The resonance peaks at the download end of the microring resonator 110 coincide with the peak wavelengths of each channel of the upper arrayed waveguide grating 150, and the resonance peaks at the through end of the microring resonator 110 coincide with the peak wavelengths of each channel of the lower arrayed waveguide grating 160.

[0028] A beam of optical signals with different wavelengths is input from the input end 3 of the straight waveguide of the microring. A part of the light is coupled into the ring resonator through the straight waveguide. An electro-optic phase shifter is loaded on the resonator. By changing the waveguide refractive index of the curved waveguide of the microring resonator filter through the voltage applied to the electro-optic phase shifter, the resonant center wavelength of the microring resonator is adjusted so that the resonant peak at the download end of the microring matches the output peak of the upper arrayed waveguide grating (AWG) (as Figure 5 ), and at the same time, the resonant peak of the through end of the microring coincides with the output peak of the lower arrayed waveguide grating (AWG) (as Figure 6 ). The optical signal coupled into the resonator through the second coupling region 6 of the microring resonator, after passing through a path of half a circumference, the wavelength signal that generates the resonance effect is coupled into the output straight waveguide 111 from the first coupling region 5 of the microring resonator, and is output from its download end. After passing through a section of curved waveguide, it enters the upper arrayed waveguide grating (150). Another part of the light, after being coupled into the ring resonator through the second coupling region 6 of the microring resonator, undergoes a phase change after passing through a path of one circumference, and then is coupled into the input straight waveguide (113) through the second coupling region 6 of the microring resonator to interfere with the optical signal of the original input straight waveguide. The interfered optical signal is output from the through end 4 of the input straight waveguide, and enters the lower arrayed waveguide grating (160) after passing through a section of curved waveguide. The finally output spectrogram after two 16-channel arrayed waveguide gratings cascaded by the microring resonator is as Figure 7 shown.

[0029] The microring resonator 110, the download end waveguide 130, the through end waveguide 140, the upper arrayed waveguide grating 150, and the lower arrayed waveguide grating 160 are all on the same top silicon layer of the SOI wafer. The size of the SOI wafer is 8 inches, the wafer thickness is 725 μm, the buried oxide layer thickness is 2 μm, and the top silicon layer thickness is 220 nm. The arrayed waveguides 10 of the upper arrayed waveguide grating 150 and the lower arrayed waveguide grating 160 are ridge waveguides with a width of 450 nm and an etching depth of 100 nm. The length difference of the upper arrayed waveguides 10 is 12.95 μm, the radius of the Rowland circle is 89.3 μm, the minimum complete radius is 50 μm, the diffraction order is 20, and the channel spacing is 6 nm. The download end waveguide 130 and the through end waveguide 140 are ridge waveguides with a width of 450 nm and a height of 200 nm. The input / output waveguides of the microring resonator 110 are all strip waveguides with a width of 450 nm. The ring resonator 112 and the coupling regions (the first coupling region 5 and the second coupling region 6) are all ridge waveguides with a width of 450 nm and an etching depth of 100 nm. The minimum distance between the input / output waveguides and the ring resonator is 200 nm. The diameter of the ring resonator is 23 μm, and the free spectral range FSR is 6 nm.

[0030] The waveguide structure of the device of the present invention is fabricated on an SOI wafer through multiple photolithography / etching semiconductor processes. After the waveguide is formed, a 1.5-μm-thick SiO2 upper cladding is deposited by PECVD process, and a flat and smooth surface is obtained through reverse etching and polishing processes. On this smooth surface, a 110-nm-thick high-resistance material TiN is deposited by PVD technology, and a TiN heating electrode is formed through photolithography / etching. It is a folded-back distribution structure with a width of 5 μm and a total length of 200 μm. A 450-nm-thick SiO2 isolation layer is deposited above the TiN electrode material by PECVD process; a heating electrode lead hole is formed above the TiN electrode through photolithography / etching technology, and the lead hole etching stops on the TiN heating electrode; finally, a 2-μm metal lead material Al is deposited by PMI technology. The Al material is connected to the TiN heating electrode, and an Al metal lead with a width of 10 μm is formed through photolithography / etching technology. The terminal structure of the Al metal lead in contact with the detection is a square with a side length of 70 μm.

[0031] Example 2, a large-channel wavelength division multiplexer based on an interleaved structure. This example is different from the single-crystalline silicon waveguide based on the SOI substrate in the device layer of Example 1. In Example 2, the device layer uses a Si3N4 waveguide, and other structures remain unchanged. The Si3N4 waveguide has lower loss and higher process tolerance compared with the single-crystalline silicon waveguide. The manufacturing process is as follows.

[0032] Step 1: Take a pure silicon wafer, clean it, obtain a buried oxide layer after thermal oxidation, and chemically polish the obtained surface by CMP technology to obtain a smooth surface;

[0033] Step 2: Deposit a silicon nitride layer on the buried oxide layer fabricated in Step 1 by LPCVD technology, polish it, and then perform photolithography, which includes spin coating, exposure, development, drying, and then etching, and finally removing the photoresist and cleaning, to prepare a complete ridge structure and strip waveguide structure, and complete the micro-ring resonator, arrayed waveguide grating, and transmission waveguide structure;

[0034] Step 3: After cleaning, deposit an upper SiO2 cladding of the Si waveguide by PECVD method. To obtain a smooth upper surface, perform CMP chemical mechanical polishing to obtain a smooth upper surface;

[0035] Step 4: After removing the photoresist and cleaning, deposit an SiO2 layer by PECVD method and deposit a TiN electrode layer by PVD method. Through photolithography and TiN etching, obtain the heating electrode TiN;

[0036] Step 5: After removing the photoresist and cleaning, after depositing the upper cladding SiO2, obtain metal lead holes through photolithography and etching;

[0037] Step Six: After de-gluing and cleaning, deposit an Al metal layer using the PVD method, and obtain metal Al leads through photolithography and etching. The metal Al is connected to the heating electrode TiN;

[0038] Step Seven: After de-gluing and cleaning, perform photolithography and deep etching to obtain an insulation groove. Finally, obtain a deep etching groove for fiber optic coupling testing through deep etching. Thus, the process of the chip is completed.

[0039] The specific embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention.

Claims

1. A large-channel wavelength division multiplexer based on an interleaved structure, comprising, from bottom to top, a substrate of a wafer, a buried oxide layer of the wafer, a device layer, and a SiO2 upper cladding of the device, characterized in that: The device layer includes a microring resonator (110), a phase shifter (120), a download-end waveguide (130), a through-end waveguide (140), an upper arrayed waveguide grating (150), and a lower arrayed waveguide grating (160); the phase shifter (120) is loaded on the microring resonator (110), the download end of the microring resonator (110) is connected to the upper arrayed waveguide grating (150) through the download-end waveguide (130), and the through end of the microring resonator (110) is connected to the lower arrayed waveguide grating (160) through the through-end waveguide (140); The microring resonator (110) includes an output straight waveguide (111), an annular resonator (112), and an input straight waveguide (113); there is a first coupling region (5) between the output straight waveguide (111) and the annular resonator (112) located below the output straight waveguide (111), and there is a second coupling region (6) between the input straight waveguide (113) and the annular resonator (112) located above the input straight waveguide (113). The phase shifter (120) is a device that connects to a power supply to adjust the resonance wavelength of the microring and acts on the annular resonator (112); The upper arrayed waveguide grating (150) includes an upper input waveguide (8), an upper input slab waveguide (9), an upper arrayed waveguide (10), an upper output slab waveguide (11), and an upper output waveguide (12); the upper input waveguide (8) is connected to the upper input slab waveguide (9); the upper input slab waveguide (9) is connected to the upper output slab waveguide (11) through the upper arrayed waveguide (10). The upper input slab waveguide (9), the upper arrayed waveguide (10), and the upper output slab waveguide (11) form a Rowland circle structure, and the upper output slab waveguide (11) is connected to the upper output waveguide (12); The lower arrayed waveguide grating (160) includes a lower input waveguide (13), a lower input slab waveguide (14), a lower arrayed waveguide (15), a lower output slab waveguide (16), and a lower output waveguide (17); the lower input waveguide (13) is connected to the lower input slab waveguide (14); the lower input slab waveguide (14) is connected to the lower output slab waveguide (16) through the lower arrayed waveguide (15). The lower input slab waveguide (14), the lower arrayed waveguide (15), and the lower output slab waveguide (16) form a Rowland circle structure, and the lower output slab waveguide (16) is connected to the lower output waveguide (17).

2. The large-channel wavelength division multiplexer based on the interleaved structure according to claim 1, wherein: The output straight waveguide (111) is divided into an output straight waveguide download end (1) and an output straight waveguide output end (2), and the input straight waveguide (113) is divided into an input straight waveguide input end (3) and an input straight waveguide through end (4).

3. The large-channel wavelength division multiplexer based on an interleaved structure according to claim 1, wherein: The download-end waveguide (130) includes a semicircular bent waveguide and a straight waveguide. The output straight waveguide download end (1) is connected to the upper input waveguide (8) of the upper arrayed waveguide grating (150) through the download-end waveguide (130).

4. The large-channel wavelength division multiplexer based on an interleaved structure according to claim 1, wherein: The through-end waveguide (140) includes an S-shaped bent waveguide and a straight waveguide. The input straight waveguide through end (4) of the microring resonator (110) is connected to the lower input waveguide (13) of the lower arrayed waveguide grating (160) through the through-end waveguide (140).

5. The large-channel wavelength division multiplexer based on the interleaved structure according to claim 1, wherein: The free spectral range (FSR) of the microring resonator (110) is equal to the channel spacing of the upper arrayed waveguide grating (150) and also equal to the channel spacing of the lower arrayed waveguide grating (160).

6. The large-channel wavelength division multiplexer based on the interleaved structure according to claim 1, characterized in that: There is a central wavelength difference of △λ between the central wavelengths of the upper arrayed waveguide grating (150) and the lower arrayed waveguide grating (160). The free spectral range (FSR) of the microring resonator (110) is equal to 2△λ, where △λ represents the channel spacing of the upper arrayed waveguide grating (150), and the channel spacing of the lower arrayed waveguide grating (160) is also △λ.

7. The large-channel wavelength division multiplexer based on the interleaved structure according to claim 1, wherein: The resonant peaks at the download end of the microring resonator (110) coincide with the peak wavelengths of the channels of the upper arrayed waveguide grating (150), and the resonant peaks at the through end of the microring resonator (110) coincide with the peak wavelengths of the channels of the lower arrayed waveguide grating (160).

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