CN218956845U - Large-channel wavelength division multiplexer - Google Patents

Abstract

The utility model relates to a large-channel wavelength division multiplexer, which comprises a substrate of a wafer, a buried oxide layer of the wafer, a device layer and an _SiO2 upper cladding layer of the device from bottom to top, and the device layers are respectively micro-rings A resonator, a phase shifter, a transmission waveguide and an arrayed waveguide grating, the phase shifter is loaded on the microring, and the microring resonator is connected with the upper and lower arrayed waveguide gratings through the transmission waveguide. The utility model cascades waveguide array gratings with two output channel peaks staggered through the microring resonator, the resonant peaks at the straight-through end of the microring coincide with the output peaks of each channel of the lower array waveguide grating, and the resonant peaks at the download end of the microring resonator coincide with the upper The output peaks of each channel of the arrayed waveguide grating coincide with each other, and the output peaks of the upper arrayed waveguide grating and the lower arrayed waveguide grating are staggered, thus forming a large-channel wavelength division multiplexer with interleaved channels, which solves the problem of wavelength division multiplexers in conventional wavelength division multiplexers. fewer problems and perform well with low crosstalk.

Description

A large channel wavelength division multiplexer

technical field

The utility model relates to a large-channel wavelength division multiplexer, which belongs to the technical field of semiconductor optical signal transmission.

Background technique

Optical fiber communication is a communication method with light wave as the carrier and optical fiber as the transmission medium. It carries more than 90% of the global communication data capacity. The biggest advantage of optical network is that it has wavelength division multiplexing technology and high-speed and large-capacity transmission capabilities. Technological progress has greatly promoted the development of optical fiber communication and brought revolutionary changes to transmission technology. Material-based silicon photonic devices have extremely small size and low cost, and their fabrication process is fully compatible with the CMOS process and can be monolithically integrated with IC circuits. With this unique advantage, it has become one of the hot spots in the field of optical fiber communication research. . At present, there are four main structures of wavelength division multiplexers in silicon photonics, etched grating (EDG), micro-ring resonator filter (Micro-Ring Resonator, MRR), cascaded MZI and arrayed waveguide grating (Silicon arrayed waveguide grating, Silicon AWG). Etched gratings are suitable for coarse division multiplexing, but cannot achieve dense wavelength division multiplexing, and the scope of application is limited: microring resonant filters cascade microrings with different radii, and use resonant wavelengths to achieve demultiplexing, which is affected by the process. The stable wavelength interval is difficult to control, and it is necessary to increase the tuning system. Multiple tuning systems will cause large additional power consumption; MZI realizes wavelength division multiplexing through the arm length difference. When the number of channels increases, the number of cascades also increases. Chip size increases, which is not conducive to integration. In view of the above reasons, these three silicon photonic devices have not been widely used in the field of wavelength division multiplexing. The silicon photonic arrayed waveguide grating is a wavelength division multiplexer/demultiplexer with the best comprehensive performance. Since the birth of the arrayed waveguide grating AWG, it is more compact and has lower insertion loss than MRR and MZI. and better crosstalk performance, so it has been extensively studied. It has been reported that a 16-channel AWG based on silicon nitride has been developed, which can achieve -30dB adjacent channel crosstalk at a loss of 0.5dB. However, due to the low refractive index difference, the entire device occupies an area of more than 1 square centimeter. Based on the high refractive index contrast property of silicon, a compact AWG with _a footprint of 400 × 600 μm was designed. However, the crosstalk between adjacent channels can be as much as 10 dB. In addition, some novel design schemes, such as folded structures, are also proposed. For example, adding reflectors to the arrayed waveguide to form a 4-channel folded AWG, the crosstalk and insertion loss are about -20dB and 3.5dB, respectively, and the results are not very ideal. Therefore, how to realize a multi-channel high-performance AWG within a compact footprint remains a challenge.

Contents of the invention

Aiming at the problems and deficiencies in the above-mentioned prior art, the utility model provides a large channel wavelength division multiplexer, which can solve the problem of large channel crosstalk of the large channel wavelength division multiplexer, the wavelength of the conventional wavelength division multiplexer Problem with low number of channels.

The technical scheme of the utility model is: a large-channel wavelength division multiplexer, which includes the substrate of the wafer, the buried oxide layer of the wafer, the device layer and the _SiO2 upper cladding layer of the device from bottom to top, and the device layer includes Microring resonator 110, phase shifter 120, download end waveguide 130, through end waveguide 140, upper arrayed waveguide grating 150 and lower arrayed waveguide grating 160; Described 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.

As a further solution of the present utility model, the microring resonator 110 includes an output straight waveguide 111, a ring resonant cavity 112, and an input straight waveguide 113; A coupling area 5, there is a second coupling area 6 between the input straight waveguide 113 and the ring resonator 112 located on the top of the input straight waveguide 113, and the phase shifter 120 is a device for connecting the power supply to adjust the resonant wavelength of the microring, acting on the ring resonator 112 on.

As a further solution of the present utility model, 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.

As a further solution of the present invention, the waveguide 130 at the input end includes a semicircular curved waveguide and a straight waveguide, and the output end 1 of the straight waveguide is connected to the upper input waveguide 8 of the arrayed waveguide grating 150 through the waveguide 130 at the output end.

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

As a further solution of the present utility model, the upper arrayed waveguide grating 150 includes an upper input waveguide 8, an upper input slab waveguide 9, an upper array 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 array waveguide 10, the upper input slab waveguide 9, the upper array 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 waveguide12.

As a further solution of the present utility model, the lower arrayed waveguide grating 160 includes a lower input waveguide 13, a lower input slab waveguide 14, a lower array 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 array waveguide 15, the lower input slab waveguide 14, the lower array 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 waveguide17.

As a further solution 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 .

As a further solution of the present utility model, 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.

As a further solution of the present utility model, the resonant peak at the download end of the microring resonator 110 coincides with the peak wavelength of each channel of the upper arrayed waveguide grating 150, and the resonant peak at the through end of the microring resonator 110 coincides with the peak wavelength of each channel of the lower arrayed waveguide grating 160. The wavelengths overlap.

The working principle of the utility model is: through the modulation effect of the phase shifter 120 loaded on the microring resonator 110, the thermo-optic/electro-optic effect is used to change the waveguide refractive index of the microring resonator filter, thereby the resonance of the microring resonator 110 The central wavelength is adjusted so that the resonant peak at the download end of the microring matches the output peak of the upper arrayed waveguide grating 150 (AWG) (as shown in Figure 5), and at the same time the resonant peak at the through end of the microring matches the output of the lower arrayed waveguide grating 160 (AWG). The peaks coincide (as shown in Figure 6). In the actual working environment, the optical signal is input from the straight waveguide under the microring, and a part of the light is coupled into the ring resonator 112 through the straight waveguide. A coupling region 5 is coupled into the output straight waveguide 111 , output from the download end, and enters the upper arrayed waveguide grating 150 after passing through a curved waveguide. Another part of the light is coupled into the ring resonant cavity 112 through the straight waveguide, passes through a perimeter path, produces a phase change, and is coupled into the input straight waveguide 113 by the second coupling region 6 of the microring resonator. The signals are interfered, and the interfered optical signal is output from the straight-through end 4 of the input straight waveguide, and enters the lower arrayed waveguide grating 160 through a curved waveguide. The arrayed waveguide grating (AWG) is composed of a strip waveguide and an arrayed waveguide. As the length of the arrayed waveguide in the arrayed waveguide grating (AWG) increases linearly, the phase change caused by the wavelength change changes linearly along the output aperture. Thus, the focal point of the light moves along the output surface of the second slab waveguide. By placing the output waveguide in an appropriate position, the spatial separation of different wavelength channels can be obtained. In the utility model, the output waveguide positions of the upper and lower arrayed waveguide gratings AWG are staggered, and the microring resonator 110 plays a role in filtering and splitting The resonant peak output from the download end of the microring resonator 110 coincides with the peaks of each channel of the upper arrayed waveguide grating 150, and the resonant peak output from the through end of the microring resonator 110 coincides with the peaks of each channel of the lower arrayed waveguide grating 160. The peaks overlap, and the resonant peaks of the two arrayed waveguide gratings superimposed by the microring resonator 110 are staggered on the spectrum diagram, as shown in Figure 7, and the free spectral range of the staggered arrayed waveguide grating is FSR>n·△λ , compared with the conventional arrayed waveguide grating AWG, it can double the number of channels, and it is a new type of large channel wavelength division multiplexer.

The beneficial effects of the utility model are: the utility model cascades two output channel waveguide array gratings with interlaced peaks through the microring resonator, and the resonant peaks at the straight-through end of the microring coincide with the output peaks of each channel of the lower array waveguide grating (AWG). , the resonance peaks of the download end of the microring resonator coincide with the output 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 arranged alternately, thus forming an interlaced channel of a large channel WDM multiplexer. It is a new large-channel wavelength division multiplexing scheme, which solves the problem of fewer wavelength channels in conventional wavelength division multiplexers, and performs well in low crosstalk.

Description of drawings

Fig. 1 is a schematic diagram of the connection of the large channel wavelength division multiplexer of the present invention;

Fig. 2 is the structure schematic diagram of the utility model microring resonator;

Fig. 3 is a schematic diagram of the structure of the arrayed waveguide grating on the utility model;

Fig. 4 is a schematic diagram of the structure of the arrayed waveguide grating under the utility model;

Fig. 5 is a matching diagram of the resonant peak of the download end of the microring of the present invention and the peak of the upper arrayed waveguide grating channel;

Fig. 6 is a matching diagram of the resonant peak at the straight-through end of the microring of the present invention and the peak of the channel of the lower arrayed waveguide grating;

Fig. 7 is an interleaving diagram of the wave peaks of the output channels of the upper arrayed waveguide grating and the lower arrayed waveguide grating of the present invention.

Each label in the figure: 1-output straight waveguide download end, 2-output straight waveguide output end, 3-input straight waveguide input end, 4-input straight waveguide straight-through end, 5-first coupling area, 6-second coupling area , 8-upper input waveguide, 9-upper input slab waveguide, 10-upper array waveguide, 11-upper output slab waveguide, 12-upper output waveguide, 13-lower input waveguide, 14-lower input slab waveguide, 15-lower array Waveguide, 16-lower output slab waveguide, 17-lower output waveguide, 110-microring 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 resonant cavity, 113 - input straight waveguide.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, the utility model is described further.

Embodiment 1: as shown in Fig. 1-Fig. 7, a kind of large channel wavelength division multiplexer, comprises the substrate of wafer, the buried oxide layer of wafer, device layer and the _SiO2 upper cladding layer of device from bottom to top , the material of the device layer is single crystal silicon, and 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 through the through end The waveguide 140 is connected to the lower arrayed waveguide grating 160 .

Wherein, the microring resonator 110 includes an output straight waveguide 111, a ring resonant cavity 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, the input The 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 at the lower part of 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 at the upper part of the input straight waveguide 113. The phaser 120 is a device connected to a power supply to adjust the resonant wavelength of the microring, acting on the ring resonant cavity 112 .

The download end waveguide 130 includes a semicircular curved waveguide and a straight waveguide, and the output straight waveguide download end 1 is connected to the upper input waveguide 8 of the arrayed waveguide grating 150 through the download end waveguide 130 . The through-end waveguide 140 includes an S-shaped curved 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, 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 Connect the upper output slab waveguide 11 through the upper array waveguide 10, the upper input slab waveguide 9, the upper array waveguide 10, and the upper output slab waveguide 11 form a Rowland circle structure, and the upper output slab waveguide 11 connects 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 array 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 array waveguide 15, the lower input slab waveguide 14, the lower array 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. The free spectral range FSR of the microring resonator 110 is equal to the channel spacing Δλ of the upper arrayed waveguide grating 150 and also equal to the channel spacing Δλ of the lower arrayed waveguide grating 160 . There is a center wavelength difference of Δλ between the center 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. The resonant peak at the download end of the microring resonator 110 coincides with the peak wavelength of each channel of the upper AWG 150 , and the resonant peak at the through end of the microring resonator 110 coincides with the peak wavelength of each channel of the lower AWG 160 .

A beam of optical signals with different wavelengths is input from the microring input straight waveguide input port 3, and a part of the light is coupled into the ring resonant cavity through the straight waveguide. An electro-optical phase shifter is loaded on the resonant cavity, and the voltage applied to the electro-optic phase shifter Change the waveguide refractive index of the curved waveguide of the microring resonator filter, thereby adjusting the resonance center wavelength of the microring resonator, so that the resonance peak at the download end of the microring matches the output peak of the upper array waveguide grating (AWG) (as shown in 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 shown in Figure 6). The optical signal coupled into the resonator through the second coupling region 6 of the microring resonator, after passing through a half-perimeter path, the wavelength signal that produces resonance is coupled from the first coupling region 5 of the microring resonator into the output straight waveguide 111 , output from its download end, and then enter the upper arrayed waveguide grating (150) after passing through a section of curved waveguide. 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 perimeter path, and then is coupled into the input straight waveguide by the second coupling region 6 of the microring resonator ( 113) Interfering with the optical signal originally input into the straight waveguide, the interfering optical signal is output from the straight-through end 4 of the input straight waveguide, and enters the lower arrayed waveguide grating (160) through a curved waveguide. The final output spectrum of two 16-channel arrayed waveguide gratings cascaded through the microring resonator is shown in Fig. 7 .

The microring resonator 110 , the download-side waveguide 130 , the through-side 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 thickness of the wafer is 725 μm, the thickness of the buried oxide layer is 2 μm, and the thickness of the top layer silicon 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 450nm and an etching depth of 100nm. The length difference of the upper arrayed waveguide 10 is 12.95 μm, the radius of the Rowland circle is 89.3 μm, and the minimum complete radius is 50μm, the diffraction order is 20, and the channel spacing is 6nm. The waveguide 130 at the download end and the waveguide 140 at the through end 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 strip waveguides with a width of 450nm, the ring resonator 112 and the coupling regions (the first coupling region 5 and the second coupling region 6) are both 450nm in width and 100nm in etching depth The minimum distance between the input/output waveguide and the ring resonator is 200nm, the diameter of the ring resonator is 23μm, and the free spectral region FSR is 6nm.

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

Embodiment 2, a large channel wavelength division multiplexer, this embodiment is different from the monocrystalline silicon waveguide based on SOI substrate in the device layer in embodiment 1, in embodiment 2, the device layer adopts Si ₃ N ₄ waveguide, other The structure remains unchanged, and the Si ₃ N ₄ waveguide has lower loss and higher process tolerance than the single crystal silicon waveguide. The manufacturing process is as follows.

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

Step 2: Use LPCVD technology to deposit a silicon nitride layer on the buried oxide layer produced in step 1, perform polishing, and then perform photolithography. Photolithography includes stripping glue, exposing, developing, drying, etching, and finally stripping and cleaning , the complete ridge structure and strip waveguide structure are prepared, and the microring resonator, arrayed waveguide grating and transmission waveguide structure are completed;

Step 3: After cleaning, the SiO ₂ cladding layer on the upper layer of the Si waveguide is deposited by PECVD. In order to obtain a smooth upper surface, CMP chemical mechanical polishing is used to obtain a smooth upper surface;

Step 4: After degelling and cleaning, a PECVD method is used to deposit a SiO ₂ layer, and a PVD method is used to deposit a TiN electrode layer. Through photolithography and TiN etching, the heated electrode TiN is obtained;

Step 5: After removing glue, cleaning, and depositing upper cladding SiO ₂ , metal lead holes are obtained by photolithography and etching;

Step 6: After degumming and cleaning, the Al metal layer is deposited by PVD method, and the metal Al lead is obtained through photolithography and etching, and the metal Al is connected to the heating electrode TiN;

Step 7: After removing glue and cleaning, perform photolithography and deep etching to obtain heat insulation grooves. Finally, a deep etched groove for fiber coupling testing is obtained by deep etching. That is, the process of chip processing is completed.

The specific embodiments of the utility model have been described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned embodiments. Various changes are made.

Claims (10)

1. A large channel wavelength division multiplexer comprises a substrate of a wafer, an oxygen-buried layer of the wafer, a device layer and SiO of the device from bottom to top ₂ The upper cladding, its characterized in that: the device layer comprises a micro-ring resonator (110), a phase shifter (120), a download end waveguide (130), a through end waveguide (140), an upper array waveguide grating (150) and a lower array waveguide grating (160); the phase shifter (120) is loaded on the micro-ring resonator (110), the downloading end of the micro-ring resonator (110) is connected with the upper array waveguide grating (150) through the downloading end waveguide (130), and the through end of the micro-ring resonator (110) is connected with the lower array waveguide grating (160) through the through end waveguide (140).

2. The large channel wavelength division multiplexer of claim 1 wherein: the micro-ring resonator (110) comprises an output straight waveguide (111), a ring resonant cavity (112) and an input straight waveguide (113); a first coupling area (5) exists between the output straight waveguide (111) and a ring resonant cavity (112) positioned at the lower part of the output straight waveguide (111), a second coupling area (6) exists between the input straight waveguide (113) and the ring resonant cavity (112) positioned at the upper part of the input straight waveguide (113), and the phase shifter (120) is a device connected with a power supply and used for adjusting the micro-ring resonant wavelength and acts on the ring resonant cavity (112).

3. The large channel wavelength division multiplexer of claim 2 wherein: the output straight waveguide (111) is divided into an output straight waveguide downloading end (1) and an output straight waveguide outputting end (2), and the input straight waveguide (113) is divided into an input straight waveguide inputting end (3) and an input straight waveguide communicating end (4).

4. The large channel wavelength division multiplexer of claim 1 wherein: the downloading end waveguide (130) comprises a semicircular bent waveguide and a straight waveguide, and the output straight waveguide downloading end (1) is connected with the upper input waveguide (8) of the upper array waveguide grating (150) through the downloading end waveguide (130).

5. The large channel wavelength division multiplexer of claim 1 wherein: the straight-through end waveguide (140) comprises an S-shaped bent waveguide and a straight waveguide, and the input straight waveguide straight-through end (4) of the micro-ring resonator (110) is connected with the lower input waveguide (13) of the lower array waveguide grating (160) through the straight-through end waveguide (140).

6. The large channel wavelength division multiplexer of claim 1 wherein: the upper array waveguide grating (150) comprises an upper input waveguide (8), an upper input slab waveguide (9), an upper array waveguide (10), an upper output slab waveguide (11) and an upper output waveguide (12); the upper input waveguide (8) is connected with the upper input slab waveguide (9); the upper input flat waveguide (9) is connected with the upper output flat waveguide (11) through the upper array waveguide (10), the upper input flat waveguide (9), the upper array waveguide (10) and the upper output flat waveguide (11) form a Roland circle structure, and the upper output flat waveguide (11) is connected with the upper output waveguide (12).

7. The large channel wavelength division multiplexer of claim 1 wherein: the lower array waveguide grating (160) comprises a lower input waveguide (13), a lower input slab waveguide (14), a lower array waveguide (15), a lower output slab waveguide (16) and a lower output waveguide (17); the lower input waveguide (13) is connected with the lower input slab waveguide (14); the lower input flat waveguide (14) is connected with the lower output flat waveguide (16) through the lower array waveguide (15), the lower input flat waveguide (14), the lower array waveguide (15) and the lower output flat waveguide (16) form a Roland circle structure, and the lower output flat waveguide (16) is connected with the lower output waveguide (17).

8. The large channel wavelength division multiplexer of 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).

9. The large channel wavelength division multiplexer of claim 1 wherein: the center wavelengths of the upper array waveguide grating (150) and the lower array waveguide grating (160) have a center wavelength difference of Deltalambda, and the free spectral range FSR of the micro-ring resonator (110) is equal to 2 Deltalambda, wherein Deltalambda represents the channel interval of the upper array waveguide grating (150), and the channel interval of the lower array waveguide grating (160) is also Deltalambda.

10. The large channel wavelength division multiplexer of claim 1 wherein: the resonance wave crest of the downloading end of the micro-ring resonator (110) coincides with the peak wavelength of each channel of the upper array waveguide grating (150), and the resonance wave crest of the through end of the micro-ring resonator (110) coincides with the peak wavelength of each channel of the lower array waveguide grating (160).

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