On-chip integrated wavelength division multiplexing receiver structure and chip

Abstract

The application discloses a kind of integrated wave division demultiplexing receiver structure and chip on chip, including wave division demultiplexing module and multiple groups of photoelectric detector, wave division demultiplexing module includes cascaded first stage wave division demultiplexer and second stage wave division demultiplexer.By wave division demultiplexing module, one original light multiplex signal containing N channels is demultiplexed into N first sub-optical signals and N second sub-optical signals.Then the sub-optical signals from the same channel are input into the corresponding photoelectric detector in the same group of photoelectric detector, to be converted into corresponding electrical signal and output respectively.Finally, all electrical signals output by the same group of photoelectric detector are configured as superimposed output, to be used as the optical detection output of corresponding channel.Compared with prior art, not only the effect of large channel bandwidth, low insertion loss and low crosstalk can be achieved, but also the effect of accurately monitoring the intensity of optical signal of each channel is achieved.

Description

Technical Field

[0001] This application relates to the field of optical communication technology, specifically to an on-chip integrated wave demultiplexer receiver structure and chip. Background Technology

[0002] With the explosive growth of internet applications such as video, live streaming, and AI, the demand for communication speed and capacity in data centers is also increasing rapidly. As the speed of optical communication modules increases, the speed of a single channel is limited by high-speed optical chips and devices and cannot be continuously increased. Therefore, multi-channel parallel processing has become the main means of expanding communication capacity. However, each additional parallel channel means adding an additional optical fiber path, which greatly increases the complexity of optical fiber interfaces and data center cabling layout. At the same time, transmitting only one signal per optical fiber is a huge waste of fiber capacity. Therefore, wavelength division multiplexing (WDM) is an important technical solution for future high-speed optical communication modules.

[0003] Monolithic integration technologies such as silicon photonics chips integrate active and passive components such as modulators, detectors, couplers, and wavelength division multiplexing / demultiplexing units onto a single chip, enabling the transmission and reception of multiple optical signals. This improves the internal integration of the module, reduces packaging costs, and lowers module power consumption. However, for silicon photonics chips, the thermal and optical drift characteristics of silicon material, processing errors, and device design limitations have made it challenging to achieve a large-channel bandwidth wavelength division multiplexing receiver integrated on a single chip. Summary of the Invention

[0004] The purpose of this application is to provide an on-chip integrated wave demultiplexer receiver structure and chip to solve the problems existing in the prior art, and has at least one advantage: the on-chip integrated wave demultiplexer receiver structure can achieve the effects of large channel bandwidth, low insertion loss and low crosstalk.

[0005] According to one aspect of this application, an on-chip integrated wave demultiplexing receiver structure is provided, including a wave demultiplexing module and multiple sets of photodetectors, wherein the wave demultiplexing module includes a cascaded first-stage wave demultiplexer and a second-stage wave demultiplexer.

[0006] The first-stage wave demultiplexer has one input port and two output ports, and the second-stage wave demultiplexer has one input port and N output ports. The second-stage wave demultiplexer includes a first-stage wave demultiplexer and a second-stage wave demultiplexer. The two output ports of the first-stage wave demultiplexer are optically connected to the input ports of the first-stage wave demultiplexer and the second-stage wave demultiplexer, respectively, where N is a positive integer greater than 1.

[0007] The first-stage wavelength demultiplexer is used to demultiplex a single original optical multiplexed signal containing N channels received at an input port, and decompose the optical signal of each channel into a first sub-optical signal and a second sub-optical signal according to the wavelength band. The first sub-optical signal of the N channels after demultiplexing is input to the input port of the first-stage wavelength demultiplexer, and the second sub-optical signal of the N channels after demultiplexing is input to the input port of the second-stage wavelength demultiplexer.

[0008] The first and second-stage wavelength division multiplexers demultiplex the received N channels of first sub-optical signals into N first sub-optical signals, and output the N first sub-optical signals from the N output ports of the first and second-stage wavelength division multiplexers respectively; the second and second-stage wavelength division multiplexers demultiplex the received N channels of second sub-optical signals into N second sub-optical signals, and output the N second sub-optical signals from the N output ports of the second and second-stage wavelength division multiplexers respectively.

[0009] One group of photodetectors is connected to one of the output ports of the first and second stage wave demultiplexers and one of the output ports of the second stage wave demultiplexer. The same group of photodetectors is configured to convert the received sub-optical signals from the same channel into corresponding electrical signals and output them. All electrical signals output by the same group of photodetectors are configured to be superimposed and output as the optical detection output of the corresponding channel.

[0010] Furthermore, for each channel, the center wavelength of the first sub-optical signal band is smaller than the center wavelength of the second sub-optical signal band.

[0011] Furthermore, for each channel, the bands of the first sub-optical signal and the second sub-optical signal partially overlap within the corresponding channel.

[0012] In some embodiments, a group of photodetectors includes at least two photodetectors, each of the at least two photodetectors having an input interface and an output interface for converting a sub-optical signal received at an input interface into a corresponding electrical signal and outputting it from the output interface.

[0013] In some implementations, all photodetectors in the same group are arranged in parallel and adjacent to each other, so as to convert the received sub-optical signals into corresponding electrical signals and output them respectively;

[0014] The output interfaces of all photodetectors in a group of photodetectors are coupled to the same node so that all electrical signals are superimposed and output through the node.

[0015] In some embodiments, a group of photodetectors includes at least one photodetector, each of the at least one photodetector having two input interfaces and one output interface, which is used to convert two sub-optical signals received from the two input interfaces into two corresponding electrical signals, and generate a combined electrical signal and output it from the output interface.

[0016] Furthermore, the two input interfaces of each photodetector are located on both sides of the photodetector to convert the received two sub-optical signals into corresponding electrical signals and output them.

[0017] In some implementations, a set of photodetectors includes at least two photodetectors.

[0018] All photodetectors in the same group are arranged in parallel and adjacent to each other, so as to convert the received at least four sub-optical signals into two corresponding combined electrical signals and output them from the corresponding output interface.

[0019] The output interfaces of all photodetectors in a group of photodetectors are coupled to the same node so that the two combined electrical signals are superimposed and output through the node.

[0020] In some implementations, the second-stage wave demultiplexer is a flat-top wave demultiplexing structure, which is used to demultiplex a single optical signal received from an input port into at least two sub-optical signals with flat-top bandwidth, and output the at least two sub-optical signals from at least two output ports respectively.

[0021] The flat-top wave decomposition and multiplexing structure includes any one of the following: etched diffraction grating structure, arrayed waveguide grating structure, Mach-Zehnder interference structure, and reflective grating structure.

[0022] In some embodiments, the wave demultiplexing module further includes a polarization beam rotator, which is used to convert a received original optical multiplexed signal into a first set of optical multiplexed signals and a second set of optical multiplexed signals having mutually perpendicular polarization states.

[0023] The first set of optical multiplexed signals and the second set of optical multiplexed signals are respectively input to the input ports corresponding to different first-stage wavelength demultiplexers.

[0024] Furthermore, it also includes multiple transimpedance amplifiers, each configured to be coupled to the output interface of each photodetector in the same group of photodetectors, for converting the received superimposed electrical signal into a corresponding voltage signal.

[0025] According to another aspect of this application, a chip is provided, the chip comprising any of the foregoing on-chip integrated wavelength demultiplexer receiver structures.

[0026] In the on-chip integrated wavelength demultiplexing receiver structure and chip provided in this application embodiment, the wavelength demultiplexing receiver structure includes a wavelength demultiplexing module and multiple sets of photodetectors. The wavelength demultiplexing module includes a cascaded first-stage wavelength demultiplexer and a second-stage wavelength demultiplexer. The wavelength demultiplexing module demultiplexes a single original optical multiplexed signal containing N channels into N first sub-optical signals and N second sub-optical signals. Then, the sub-optical signals from the same channel are respectively input to the corresponding photodetectors in the same set of photodetectors to be converted into corresponding electrical signals and output. Finally, all electrical signals output from the same set of photodetectors are configured as a superimposed output to serve as the optical detection output of the corresponding channel. Compared with existing technologies, this not only achieves large channel bandwidth, low insertion loss, and low crosstalk, but also enables accurate monitoring of the intensity of the optical signals in each channel. Attached Figure Description

[0027] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0028] Figure 1 This is a schematic diagram of the standard CWDM channel spectrum and the ideal silicon optical demultiplexer channel spectrum.

[0029] Figure 2 This is a schematic diagram of the channel spectrum that can be achieved by silicon optical demultiplexers in commonly used technologies.

[0030] Figure 3 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for the first embodiment of this application.

[0031] Figure 4 This is a schematic diagram of the channel response of the first-stage wave demultiplexer in a wave demultiplexing module provided in the first embodiment of this application.

[0032] Figure 5 This is a schematic diagram of the channel response of a first-stage wave demultiplexer A and a second-stage wave demultiplexer B in a wave demultiplexing module provided in the first embodiment of this application.

[0033] Figure 6A This is a schematic diagram of the equivalent photodetector response of a corresponding channel A output, provided for the first embodiment of this application.

[0034] Figure 6B This is a schematic diagram of the equivalent photodetector response of a corresponding channel B output provided in the first embodiment of this application.

[0035] Figure 6CThis is a schematic diagram of the equivalent photoelectric response of a wave demultiplexing receiver structure provided in the first embodiment of this application.

[0036] Figure 7 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for a second embodiment of this application.

[0037] Figure 8 This is a functional block diagram of an on-chip integrated wave demultiplexing receiver structure provided for the third embodiment of this application.

[0038] Figure 9 This is a functional block diagram of another on-chip integrated wave demultiplexer receiver structure provided for the third embodiment of this application.

[0039] Figure 10 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for the fourth embodiment of this application.

[0040] Figure 11 This is a schematic diagram of the channel response of the first-stage wave demultiplexer in a wave demultiplexing module provided in the fourth embodiment of this application.

[0041] Figure 12 This is a schematic diagram of the channel response of the second-stage wave demultiplexer A and the second-stage wave demultiplexer B in a wave demultiplexing module provided in the fourth embodiment of this application.

[0042] Figure 13A This is a schematic diagram of the equivalent photodetector response of a corresponding channel A output, provided in the fourth embodiment of this application.

[0043] Figure 13B This is a schematic diagram of the equivalent photodetector response of a corresponding channel B output provided in the fourth embodiment of this application.

[0044] Figure 13C This is a schematic diagram of the equivalent photoelectric response of a wave demultiplexing receiver structure provided in the fourth embodiment of this application.

[0045] Figure 14 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided in the fifth embodiment of this application.

[0046] Figure 15 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for the sixth embodiment of this application.

[0047] Figure 16 This is a functional block diagram of another on-chip integrated wave demultiplexer receiver structure provided in the sixth embodiment of this application.

[0048] Key reference numerals:

[0049] 200 Wavelength demultiplexing module; 210 First-stage wavelength demultiplexer; 220 Second-stage wavelength demultiplexer; 230 Polarization beam splitter rotator; 300 Photodetector; 400 Transimpedance amplifier. Detailed Implementation

[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0051] The terms "first" and "second" used herein are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] The following disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or reference letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0054] Currently, the channel bandwidth of commonly used silicon photonics chip-integrated wave demultiplexer receiver structures is mainly limited by the channel bandwidth of the silicon photonics wave demultiplexer. The channel bandwidth of the silicon photonics wave demultiplexer is mainly limited by the thermo-optical sensitivity of silicon material and processing errors. Figure 1 This is a schematic diagram showing the channel spectrum of a standard CWDM and the channel spectrum of an ideal silicon optical demultiplexer. (See diagram for example.) Figure 1 As shown, in order for the channel bandwidth of the silicon optical wave demultiplexer to cover the channel range of CWDM4 (exemplarily, the CWDM4 system has 4 channels, each with a center wavelength of 1271nm, 1291nm, 1311nm and 1331nm respectively), it is necessary to expand the channel bandwidth of the silicon optical wave demultiplexer during the design phase to improve the wavelength drift problem of the wave demultiplexer caused by temperature changes and process errors. Figure 1 The solid line represents the channel bandwidth of an ideal silicon optical wave demultiplexer, while the dashed line represents the channel bandwidth of a standard CWDM.

[0055] Figure 2 This is a schematic diagram of the channel spectrum that can be achieved by silicon optical demultiplexers in commonly used technologies.

[0056] like Figure 2 As shown, the "solid line" represents the actual channel bandwidth of silicon optical demultiplexers in commonly used technologies, while the "dashed line" represents the channel bandwidth of standard CWDM. It is evident that in commonly used technologies, to achieve the large channel bandwidth of silicon optical demultiplexers, insertion loss and crosstalk are often sacrificed.

[0057] One embodiment of this application provides an on-chip integrated wave demultiplexing receiver structure, which includes: a wave demultiplexing module and multiple sets of photodetectors. The wave demultiplexing module includes a cascaded first-stage wave demultiplexer and a second-stage wave demultiplexer.

[0058] The first-stage wavelength division multiplexer has one input port and two output ports. The second-stage wavelength division multiplexer has one input port and N output ports. The second-stage wavelength division multiplexer includes a first-stage wavelength division multiplexer and a second-stage wavelength division multiplexer. The two output ports of the first-stage wavelength division multiplexer are optically connected to the input ports of the first-stage wavelength division multiplexer and the second-stage wavelength division multiplexer, respectively, where N is a positive integer greater than 1.

[0059] The first-stage wavelength demultiplexer is used to demultiplex a single original optical multiplexed signal containing N channels received at one input port, and decomposes the optical signal of each channel into a first sub-optical signal and a second sub-optical signal according to the wavelength band. The first sub-optical signal of the N channels after demultiplexing is input to the input port of the first-stage wavelength demultiplexer, and the second sub-optical signal of the N channels after demultiplexing is input to the input port of the second-stage wavelength demultiplexer.

[0060] The first and second stage wave demultiplexers demultiplex the received N channels of first sub-optical signals into N first sub-optical signals, and output the N first sub-optical signals from the first and second stage wave demultiplexers respectively from N output ports; the second stage wave demultiplexer demultiplexes the received N channels of second sub-optical signals into N second sub-optical signals, and output the N second sub-optical signals from the N output ports of the second stage wave demultiplexer respectively.

[0061] One group of photodetectors is connected to one output port of the first-to-second-stage wave demultiplexer and one output port of the second-to-second-stage wave demultiplexer. The same group of photodetectors is configured to convert received sub-optical signals from the same channel into corresponding electrical signals and output them. All electrical signals output from the same group of photodetectors are configured to be superimposed and output as the optical detection output of the corresponding channel.

[0062] It should be noted that, in this embodiment of the invention, the original optical multiplexed signal received by the on-chip integrated wavelength demultiplexing receiver structure contains multiple optical signal channels, and each channel corresponds to a different center wavelength. For example, each channel can be considered as a set, where each set contains optical signals with a specific center wavelength. Assuming we have N channels, these channels can be represented by an index set {C1, C2, C3, ..., CN}, where the index Ci of each channel corresponds to an optical signal with a center wavelength λi. Through the on-chip integrated wavelength demultiplexing receiver structure, these optical signal channels can be decomposed and demodulated, thereby extracting information about each channel in the original optical multiplexed signal.

[0063] This application's embodiments aim to decompose the optical signal of each channel in a single original optical multiplexed signal containing N channels into a first sub-optical signal and a second sub-optical signal according to wavelength band using a wavelength decomposition and multiplexing module. Then, the first sub-optical signals of the N channels are further decomposed into N first sub-optical signals with different center wavelengths, and the second sub-optical signals of the N channels are further decomposed into N second sub-optical signals with different center wavelengths. At least two sub-optical signals from the same channel are then input to corresponding photodetectors in the same group of photodetectors to be converted into corresponding electrical signals and output. Finally, all electrical signals output from the same group of photodetectors are configured as a superimposed output to serve as the optical detection output for the corresponding channel. Compared to commonly used technologies, the on-chip integrated wavelength decomposition and multiplexing receiver structure of this application not only achieves large channel bandwidth, low insertion loss, and low crosstalk, but also achieves accurate monitoring of the intensity of the optical signals in each channel.

[0064] Example 1

[0065] Figure 3This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for the first embodiment of this application.

[0066] See Figure 3 One embodiment of this application provides an on-chip integrated wave demultiplexing receiver structure, which includes: a wave demultiplexing module 200 and multiple sets of photodetectors 300. The wave demultiplexing module 200 includes a cascaded first-stage wave demultiplexer 210 and two second-stage wave demultiplexers 220.

[0067] The first-stage wavelength demultiplexer 210 has one input port 211 and two output ports 212. It is used to demultiplex a single original optical multiplexed signal containing N channels received at the input port 211, decompose each channel's optical signal into a first sub-optical signal and a second sub-optical signal according to wavelength, and output the demultiplexed N-channel first sub-optical signal and N-channel second sub-optical signal from the two output ports 212 respectively. Here, N is a positive integer greater than 1.

[0068] The second-stage wavelength demultiplexer 220 has one input port 221 and N output ports 222. The second-stage wavelength demultiplexer 220 includes a first-stage wavelength demultiplexer A and a second-stage wavelength demultiplexer B. The two output ports 212 of the first-stage wavelength demultiplexer 210 are optically connected to the input ports 221 of the first-stage wavelength demultiplexer A and the input ports of the second-stage wavelength demultiplexer B, respectively. The first-stage wavelength demultiplexer demultiplexes the N channels of first sub-optical signals received at one input port 221 into N first sub-optical signals, and outputs the N first sub-optical signals from the N output ports 222 of the first-stage wavelength demultiplexer A. The second-stage wavelength demultiplexer B demultiplexes the N channels of second sub-optical signals received at one input port 221 into N second sub-optical signals, and outputs the N second sub-optical signals from the N output ports 222 of the second-stage wavelength demultiplexer B.

[0069] In this embodiment, one group of photodetectors 300 is connected to one output port 222 corresponding to the first and second-stage wave demultiplexer A and one output port 222 corresponding to the second-stage wave demultiplexer B. The same group of photodetectors 300 is configured to convert the received first and second sub-optical signals from the same channel into corresponding electrical signals and output them. All electrical signals output by the same group of photodetectors 300 are configured to be superimposed and output to achieve the detection of optical signals from the corresponding channel.

[0070] For example, in some embodiments, a set of photodetectors includes at least two photodetectors 300, each of the at least two photodetectors 300 having an input interface and an output interface. This is used to convert a sub-optical signal received at one input interface into a corresponding electrical signal and output it from the output interface.

[0071] Specifically, all photodetectors 300 in the same group of photodetectors are arranged in parallel and adjacent to each other to convert each received sub-optical signal into a corresponding electrical signal and output it. Since high-frequency electrical signals are attenuated during transmission in the electrodes, when two sub-optical signals (first sub-optical signal and second sub-optical signal) corresponding to the same channel are converted into corresponding electrical signals and then superimposed, if the photodetectors 300 used for conversion are far apart, the high-frequency signals will be significantly attenuated before being added. On the other hand, the electrode traces connecting two photodetectors 300 that are far apart have large parasitic parameters, which affect the high-frequency performance.

[0072] For example, each photodetector 300 includes a light absorption region and an electrode output region. The first sub-optical signal and the second sub-optical signal corresponding to the same channel are respectively input to the light absorption region of the corresponding photodetector 300 through the two input interfaces of the two photodetectors, and are respectively converted into corresponding electrical signals and output from the two output interfaces of the two photodetectors.

[0073] When a group of photodetectors includes two or more photodetectors 300, the output interfaces of all photodetectors 300 in the group are coupled to the same node (e.g., N1) so that the superimposed electrical signal is output through the node (e.g., N1) and the superimposed electrical signal is used as the detection result of the optical signal of the corresponding channel.

[0074] For example, the first-stage wavelength demultiplexer demultiplexes a single original optical multiplexed signal containing multiple channels received from one input port into two optical multiplexed signals, and inputs the two optical multiplexed signals to the input ports corresponding to different second-stage wavelength demultiplexers; wherein the number of sub-optical signals contained in each of the two optical multiplexed signals corresponds to the number of channels, so that they are output from the output ports corresponding to different second-stage wavelength demultiplexers.

[0075] Taking an input light containing four CWDM channels with wavelengths λ1, λ2, λ3, and λ4 as an example, where λ1, λ2, λ3...λ4 are arranged in ascending or descending order of their center wavelengths. The input light first enters the input port 211 of the first-stage wavelength demultiplexer 210. After passing through the first-stage wavelength demultiplexer 210, the input light is split into two paths and output from the two output ports 212 of the first-stage wavelength demultiplexer 210 respectively. The first optical signal contains four sub-optical signals (first sub-optical signals) with wavelengths λ1A, λ2A, λ3A, and λ4A, and the second optical signal contains four sub-optical signals (second sub-optical signals) with wavelengths λ1B, λ2B, λ3B, and λ4B.

[0076] Figure 4 This is a schematic diagram of the channel response of the first-stage wave demultiplexer in a wave demultiplexing module provided in the first embodiment of this application.

[0077] like Figure 4 As shown, the first-stage wavelength demultiplexer 210 demultiplexes the signal into two optical signals. The number of sub-optical signals contained in the first optical signal is the same as the number of sub-optical signals contained in the second optical signal, and each corresponds to the number of channels. These sub-optical signals are then output from different output ports of the second-stage wavelength demultiplexer. The first optical signal contains sub-optical signals with four wavelengths: λ1A, λ2A, λ3A, and λ4A. The second optical signal contains sub-optical signals with four wavelengths: λ1B, λ2B, λ3B, and λ4B. In this case, for each channel, the center wavelength of the first sub-optical signal in the first optical signal is smaller than the center wavelength of the second sub-optical signal in the second optical signal.

[0078] For example, in this embodiment, for each channel, the bands of the first sub-optical signal and the bands of the second sub-optical signal are separated from each other.

[0079] Furthermore, λ1A, λ2A, λ3A, and λ4A are sequentially spaced by a predetermined wavelength interval, for example, a difference of 20 nm between their center wavelengths. Similarly, λ1B, λ2B, λ3B, and λ4B are sequentially spaced by a predetermined wavelength interval, for example, a difference of 20 nm between their center wavelengths. This ensures that the center wavelengths of adjacent channels in the output optical multiplexed signal have a predetermined wavelength interval, reducing crosstalk between adjacent channels.

[0080] The first optical signals λ1A, λ2A, λ3A, and λ4A, and the second optical signals λ1B, λ2B, λ3B, and λ4B are respectively input to one input port of the first and second-stage wavelength demultiplexer A and one input port of the second-stage wavelength demultiplexer B. Specifically, after the first optical signals λ1A, λ2A, λ3A, and λ4A are input to the first and second-stage wavelength demultiplexer A, they are split into four optical signals and output from the four output ports of the first and second-stage wavelength demultiplexer A, respectively, corresponding to sub-optical signals of the four wavelengths λ1A, λ2A, λ3A, and λ4A; after the second optical signals λ1B, λ2B, λ3B, and λ4B are input to the second and second-stage wavelength demultiplexer B, they are split into four optical signals and output from the four output ports of the first and second-stage wavelength demultiplexer A, respectively, corresponding to sub-optical signals of the four wavelengths λ1A, λ2A, λ3A, and λ4A. The four output ports of the second-stage wavelength demultiplexer B output sub-optical signals corresponding to the four wavelengths λ1B, λ2B, λ3B, and λ4B, respectively. After passing through the first and second-stage wavelength demultiplexers A and B, the light is divided into a total of eight paths, corresponding to the sub-optical signals (first sub-optical signals) with wavelengths λ1A, λ2A, λ3A, and λ4A, and the sub-optical signals (second sub-optical signals) with wavelengths λ1B, λ2B, λ3B, and λ4B, respectively. It should be noted that the second-stage wavelength demultiplexer has a specific internal design structure that can directly decompose one optical signal into four sub-optical signals.

[0081] Figure 5 This is a schematic diagram of the channel response of the first and second stage wave demultiplexer A and the second stage wave demultiplexer B in the wave demultiplexing module provided in the first embodiment of this application.

[0082] like Figure 5 As shown, the four output ports of the first and second-stage wavelength demultiplexer A sequentially output four sub-optical signals (first sub-optical signals) of λ1A, λ2A, λ3A, and λ4A, and the four output ports of the second and second-stage wavelength demultiplexer B sequentially output four sub-optical signals (second sub-optical signals) of λ1B, λ2B, λ3B, and λ4B. The bands of λ1A, λ2A, λ3A, and λ4A are non-adjacent, as are the bands of λ1B, λ2B, λ3B, and λ4B.

[0083] For example, after transmission via a trace (e.g., an optical waveguide), the first sub-optical signal λ1A and the second sub-optical signal λ1B corresponding to channel 1 are simultaneously input to two photodetectors 300 (photodetector λ1A and photodetector λ1B) in a set of photodetectors 300. Photodetector λ1A and photodetector λ1B convert the received optical signal into their respective corresponding electrical signals and output them, which are then superimposed at node N1 to output the electrical signal corresponding to channel 1. Similarly, the first sub-optical signal λ2A and the second sub-optical signal λ2B corresponding to channel 2 are simultaneously input to two photodetectors 300 (photodetector λ2A and photodetector λ2B) in a set of photodetectors 300. Photodetector λ2A and photodetector λ2B convert the received optical signal into their respective corresponding electrical signals and then superimpose them at node N2 to output the electrical signal corresponding to channel 2. The first sub-optical signal λ3A and the second sub-optical signal λ3B corresponding to channel 3 are simultaneously input to two photodetectors 300 (photodetector λ3A and photodetector λ3B) in a set of photodetectors 300. Photodetectors λ3A and λ3B convert the received optical signals into their respective electrical signals, and then superimpose them at node N3 to output the electrical signal corresponding to channel 3. The first sub-optical signal λ4A and the second sub-optical signal λ4B corresponding to channel 4 are simultaneously input to two photodetectors 300 (photodetector λ4A and photodetector λ4B) in a set of photodetectors 300. Photodetectors λ4A and λ4B convert the received optical signals into their respective electrical signals, and then superimpose them at node N4 to output the electrical signal corresponding to channel 4.

[0084] Figure 6A This is a schematic diagram of the equivalent photodetector response of a corresponding channel A output, provided for the first embodiment of this application.

[0085] Figure 6B This is a schematic diagram of the equivalent photodetector response of a corresponding channel B output provided in the first embodiment of this application.

[0086] Figure 6C This is a schematic diagram of the equivalent photoelectric response of a wave demultiplexing receiver structure provided in the first embodiment of this application.

[0087] like Figures 6A-6C As shown, by combining the overall responses of the wave demultiplexing receivers corresponding to channel A and channel B, it can be seen that, by adopting the technical solution provided in the embodiments of this application, the actual response spectrum of each channel has the advantages of large channel bandwidth and low insertion loss. Figure 6C In the diagram, the "dashed line" represents the standard response spectrum for each channel, and the "solid line" represents the actual response spectrum for each channel.

[0088] For example, in an embodiment of the present invention, the second-stage wave demultiplexer is a flat-top wave demultiplexing structure, which is used to demultiplex a single optical signal received from an input port into at least two sub-optical signals with flat-top bandwidth, and output the at least two sub-optical signals from at least two output ports respectively.

[0089] The flat-top wave demultiplexing structure includes any one of the following: etched diffraction grating structure, arrayed waveguide grating structure, Mach-Zehnder interference structure, and reflective grating structure. At least two output ports of the flat-top wave demultiplexing structure can output at least two narrow-bandwidth optical signals with flat-top bandwidth.

[0090] In some embodiments, the on-chip integrated wave demultiplexing receiver architecture also includes multiple transimpedance amplifiers 400. Each transimpedance amplifier 400 is configured to be coupled to the output interface of each photodetector 300 in the same group of photodetectors 300 to convert the received superimposed current signal into a corresponding voltage signal. Specifically, the output interface of each photodetector 300 in the same group of photodetectors 300 is coupled to the same transimpedance amplifier 400 via the same node. The transimpedance amplifier 400 can be used to convert the received superimposed current signal into a voltage signal and amplify it.

[0091] Example 2

[0092] Figure 7 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for a second embodiment of this application.

[0093] See Figure 7 The difference from the first embodiment is that in the second embodiment, a group of photodetectors 300 includes one photodetector 300 with two input interfaces and one output interface. This photodetector 300 converts the first and second sub-optical signals received from the two input interfaces, corresponding to the same channel, into two corresponding electrical signals, and then merges the two electrical signals to generate a combined electrical signal, which is output from the output interface. That is, each photodetector 300 has dual input interfaces for simultaneously receiving two sub-optical signals from the same channel. It should be understood that the center wavelengths of these two sub-optical signals are close.

[0094] For example, each photodetector 300 has two input interfaces located on opposite sides to convert the received two optical signals into corresponding electrical signals and output them. Each photodetector 300 includes a light absorption region and an electrode output region. The first sub-optical signal and the second sub-optical signal corresponding to the same channel are input to the light absorption region of the photodetector 300 via the two input interfaces, respectively, and converted into corresponding photocurrents before being output from the electrode output region of the photodetector 300. The two electrical signals are combined in the electrode output region of the photodetector 300 and then output from the output interface of the photodetector 300.

[0095] Furthermore, each photodetector 300 output interface is coupled to the same transimpedance amplifier 400 via the same node. The transimpedance amplifier 400 can be used to convert the received superimposed current signal into a voltage signal and amplify it.

[0096] Example 3

[0097] Figure 8 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for the third embodiment of this application.

[0098] See Figure 8 Since light typically has two polarization states, and conventional wavelength division multiplexers / demultiplexers can only operate in one of these polarization states, a difference from the first and second embodiments described above is that, in this embodiment, the wavelength division demultiplexing module 200 further includes a polarization beam rotator 230 to achieve dual-polarization large-channel wavelength division multiplexing reception. The polarization beam rotator 230 is used to convert the received original optical multiplexed signal into a first set of optical multiplexed signals and a second set of optical multiplexed signals with mutually perpendicular polarization states; the first set of optical multiplexed signals and the second set of optical multiplexed signals are respectively input to the input ports corresponding to two different first-stage wavelength division demultiplexers.

[0099] Taking an input light containing four CWDM channels with wavelengths λ1, λ2, λ3, and λ4 as an example, where λ1, λ2, λ3...λ4 are arranged in ascending or descending order of their center wavelengths. In this embodiment, λ1, λ2, λ3, and λ4 respectively include two polarization modes: TE and TM. The input light first enters the polarization beam splitter rotator 230. After being processed by the polarization beam splitter rotator 230, the input light is split into two paths and output from the two output ports of the polarization beam splitter rotator. One path contains optical signals of four wavelengths (λ1, λ2, λ3, and λ4) in the TE polarization mode, and the other path contains optical signals of four wavelengths (λ1, λ2, λ3, and λ4) in the TM polarization mode. The input light containing TE polarization modes λ1, λ2, λ3, and λ4 and the input light containing TM polarization modes λ1, λ2, λ3, and λ4 are respectively input to different input ports of the first-stage wavelength demultiplexer 210.

[0100] Specifically, the input light containing TE polarization states λ1, λ2, λ3, and λ4 is split into two paths after passing through the first-stage wavelength demultiplexer 210 and output from the two output ports of the first-stage wavelength demultiplexer 210. The first optical signal is TE polarized and contains four sub-optical signals (first sub-optical signals) with wavelengths λ1A, λ2A, λ3A, and λ4A. The second optical signal is TE polarized and contains four sub-optical signals (second sub-optical signals) with wavelengths λ1B, λ2B, λ3B, and λ4B. The number of sub-optical signals in the first and second optical signals is the same and corresponds to the four channels. Furthermore, the center wavelengths of TE polarization states λ1A, λ2A, λ3A, and λ4A in the first optical signal are not adjacent, and the center wavelengths of TE polarization states λ1B, λ2B, λ3B, and λ4B in the second optical signal are not adjacent. This ensures that the center wavelengths of adjacent channels in the same output optical multiplexed signal have a predetermined wavelength interval, reducing signal crosstalk between adjacent channels.

[0101] The first and second optical signals in the TE polarization state are input to the input ports of the first and second stage wave demultiplexer A and the second stage wave demultiplexer B, respectively. Specifically, the first optical signal λ1A, λ2A, λ3A, and λ4A in the TE polarization state is input into the first and second-stage wavelength demultiplexer A and split into four paths, which are output from the four output ports of the first and second-stage wavelength demultiplexer A, corresponding to the four wavelengths λ1A, λ2A, λ3A, and λ4A, respectively. The second optical signal λ1B, λ2B, λ3B, and λ4B in the TE polarization state is input into the second and second-stage wavelength demultiplexer B and split into four paths, which are output from the four output ports of the second and second-stage wavelength demultiplexer B, corresponding to the four wavelengths λ1B, λ2B, λ3B, and λ4B, respectively. After passing through the first and second-stage wavelength demultiplexer A and the second and second-stage wavelength demultiplexer B, the TE polarization state light is split into a total of eight paths, corresponding to the sub-optical signals with wavelengths λ1A, λ2A, λ3A, and λ4A and the sub-optical signals with wavelengths λ1B, λ2B, λ3B, and λ4B, respectively.

[0102] Specifically, the input light containing TM polarization states λ1, λ2, λ3, and λ4 is split into two paths after passing through the first-stage wavelength demultiplexer 210 and output from the two output ports of the first-stage wavelength demultiplexer 210. The first optical signal is TM polarized and contains four sub-optical signals (first sub-optical signals) with wavelengths λ1A, λ2A, λ3A, and λ4A. The second optical signal is TM polarized and contains four sub-optical signals (second sub-optical signals) with wavelengths λ1B, λ2B, λ3B, and λ4B. The number of sub-optical signals in the first and second optical signals is the same and corresponds to the four channels. Furthermore, the center wavelengths of λ1A, λ2A, λ3A, and λ4A in the first optical signal are not adjacent, and the center wavelengths of λ1B, λ2B, λ3B, and λ4B in the second optical signal are not adjacent. This ensures that there is a predetermined wavelength interval between the center wavelengths of adjacent channels in the same output optical signal, reducing signal crosstalk between adjacent channels.

[0103] The first and second optical signals in TM polarization state are input to the input ports of the first and second stage wave demultiplexer A and the second stage wave demultiplexer B, respectively. Specifically, the first optical signal λ1A, λ2A, λ3A, and λ4A in the TM polarization state is input into the first and second-stage wavelength demultiplexer A and split into four paths, which are output from the four output ports of the first and second-stage wavelength demultiplexer A, corresponding to the four wavelengths λ1A, λ2A, λ3A, and λ4A, respectively. The second optical signal λ1B, λ2B, λ3B, and λ4B in the TM polarization state is input into the second and second-stage wavelength demultiplexer B and split into four paths, which are output from the four output ports of the second and second-stage wavelength demultiplexer B, corresponding to the four wavelengths λ1B, λ2B, λ3B, and λ4B, respectively. After passing through the first and second-stage wavelength demultiplexer A and the second and second-stage wavelength demultiplexer B, the TM polarization state light is split into a total of eight paths, corresponding to the sub-optical signals with wavelengths λ1A, λ2A, λ3A, and λ4A and the sub-optical signals with wavelengths λ1B, λ2B, λ3B, and λ4B, respectively.

[0104] Continue to refer to Figure 8 As shown, exemplarily, when a set of photodetectors 300 includes two photodetectors 300, the two photodetectors 300 in the set are arranged in parallel and adjacent to each other. Each photodetector 300 in the set has two input interfaces and one output interface. The sub-optical signal of λ1A with TE polarization state and the sub-optical signal of λ1B with TM polarization state corresponding to the λ1 channel are respectively input to the two input interfaces of one photodetector λ1 in the set. The sub-optical signal of λ1B with TE polarization state and the sub-optical signal of λ1A with TM polarization state corresponding to the λ1 channel are respectively input to the two input interfaces of the other photodetector λ1 in the set. After the two photodetectors 300 in the set convert the received dual-polarization sub-optical signals into electrical signals, they output them from the output interfaces of all photodetectors 300 in the set. Then, they are superimposed to form the electrical signal corresponding to the λ1 channel and output to the transimpedance amplifier 400 to obtain the corresponding voltage signal. The photoelectric conversion for the other corresponding λ2, λ3, and λ4 channels is similar and will not be described in detail here.

[0105] In other implementations, such as Figure 9As shown, when each photodetector 300 in a group of photodetectors 300 has only one input interface, the sub-optical signals of λ1A and λ1B corresponding to the TE polarization state of channel λ1 are respectively input to the input interfaces of the first two photodetectors 300 in the group of photodetectors 300. The sub-optical signals of λ1A and λ1B corresponding to the TM polarization state of channel λ1 are respectively input to the input interfaces of the last two photodetectors 300 in the group of photodetectors 300. After all the photodetectors 300 in the group of photodetectors 300 convert the received optical signals into electrical signals, they are output from the output interfaces of all the photodetectors 300 in the group of photodetectors 300. Then, they are superimposed to form the electrical signal corresponding to channel λ1 and output to the transimpedance amplifier 400 to obtain the corresponding voltage signal. The photoelectric conversion for channels λ2, λ3, and λ4 is similar and will not be described in detail here.

[0106] Example 4

[0107] Figure 10 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for the fourth embodiment of this application. Figure 11 This is a schematic diagram of the channel response of the first-stage wave demultiplexer in a wave demultiplexing module provided in the fourth embodiment of this application. Figure 12 This is a schematic diagram of the channel response of the first and second stage wave demultiplexer A and the second stage wave demultiplexer B in a wave demultiplexing module provided in the fourth embodiment of this application. Figure 13A This is a schematic diagram of the equivalent photodetector response of a corresponding channel A output, provided in the fourth embodiment of this application. Figure 13B This is a schematic diagram of the equivalent photodetector response of a corresponding channel B output provided in the fourth embodiment of this application. Figure 13C This is a schematic diagram of the equivalent photoelectric response of a wave demultiplexing receiver structure provided in the fourth embodiment of this application.

[0108] like Figures 10-13C As shown, in this embodiment, the functional block diagram of the on-chip integrated wavelength demultiplexing receiver structure is similar to that of Embodiment 1. The only difference is that, for each channel, after demultiplexing by the first-stage wavelength demultiplexer, the two optical waves corresponding to that channel are not separate from each other, but overlap in the center band. Taking the channel corresponding to wavelength λ1 as an example, a portion of the light in the center band λ1C of wavelength λ1 will be input as one light path along with λ1A into a second-stage wavelength demultiplexer 220, and another portion of the light in the center band λ1C of wavelength λ1 will be input as another light path along with λ1B into another second-stage wavelength demultiplexer 220. The wavelength decomposition process for the other channels corresponding to wavelengths λ2, λ3, and λ4 is similar and will not be described in detail here.

[0109] Specifically, taking an input light containing four CWDM channels with wavelengths λ1, λ2, λ3, and λ4 as an example, where λ1, λ2, λ3...λ4 are arranged in ascending or descending order of their center wavelengths. The input light first enters the input port of the first-stage wavelength demultiplexer 210. After passing through the first-stage wavelength demultiplexer 210, the input light is split into two paths and output from the two output ports of the first-stage wavelength demultiplexer 210 respectively. When the input light wavelengths are λ1C, λ2C, λ3C, and λ4C (where λ1C, λ2C, λ3C, and λ4C correspond to the center bands of wavelengths λ1, λ2, λ3, and λ4 respectively), λ1C, λ2C, λ3C, and λ4C will be simultaneously output from their respective corresponding output ports of different second-stage wavelength demultiplexers 220.

[0110] The first optical signal comprises four sub-optical signals (first sub-optical signals) with wavelengths λ1A+λ1C, λ2A+λ2C, λ3A+λ3C, and λ4A+λ4C. The second optical signal comprises four sub-optical signals (second sub-optical signals) with wavelengths λ1B+λ1C, λ2B+λ2C, λ3B+λ3C, and λ4B+λ4C. In this case, for each channel, the wavelengths of the first sub-optical signal in the first optical signal and the second sub-optical signal in the second optical signal partially overlap within the corresponding channel.

[0111] The four output ports of the first and second-stage wavelength demultiplexer A sequentially output sub-optical signals of four wavelengths: λ1A+λ1C, λ2A+λ2C, λ3A+λ3C, and λ4A+λ4C. Similarly, the four output ports of the second and second-stage wavelength demultiplexer B sequentially output sub-optical signals of four wavelengths: λ1B+λ1C, λ2B+λ2C, λ3B+λ3C, and λ4B+λ4C. In this case, for each channel, the center wavelength of the first sub-optical signal in the first optical signal band is smaller than the center wavelength of the second sub-optical signal in the second optical signal band. Specifically, the bands of λ1A+λ1C, λ2A+λ2C, λ3A+λ3C, and λ4A+λ4C are non-adjacent, as are the bands of λ1B+λ1C, λ2B+λ2C, λ3B+λ3C, and λ4B+λ4C.

[0112] After transmission via a trace (e.g., an optical waveguide), the first sub-optical signal λ1A+λ1C and the second sub-optical signal λ1B+λ1C corresponding to channel 1 are simultaneously input to two photodetectors 300 (photodetectors λ1A,λ1C and photodetectors λ1B,λ1C, respectively) in a set of photodetectors 300. Photodetectors λ1A,λ1C and photodetectors λ1B,λ1C respectively convert the received optical signal into their respective corresponding electrical signals and output them. These signals are then superimposed at node N1 to output the electrical signal corresponding to channel 1. Similarly, the first sub-optical signal λ2A+λ2C and the second sub-optical signal λ2B+λ2C corresponding to channel 2 are simultaneously input to two photodetectors 300 (photodetectors λ2A,λ2C and photodetectors λ2B,λ2C, respectively) in a set of photodetectors 300. Photodetectors λ2A,λ2C and photodetectors λ2B,λ2C respectively convert the received optical signal into their respective corresponding electrical signals and then superimpose them at node N2 to output the electrical signal corresponding to channel 2. The first sub-optical signal λ3A+λ3C and the second sub-optical signal λ3B+λ3C of channel 3 are simultaneously input to two photodetectors 300 (photodetectors λ3A,λ3C and photodetectors λ3B,λ3C, respectively). Photodetectors λ3A,λ3C and photodetectors λ3B,λ3C respectively convert the received optical signals into their corresponding electrical signals, and then superimpose them at node N3 to output the electrical signal corresponding to channel 3. The first sub-optical signal λ4A+λ4C and the second sub-optical signal λ4B+λ4C of channel 4 are simultaneously input to two photodetectors 300 (photodetectors λ4A,λ4C and photodetectors λ4B,λ4C, respectively). Photodetectors λ4A,λ4C and photodetectors λ4B,λ4C respectively convert the received optical signals into their corresponding electrical signals, and then superimpose them at node N4 to output the electrical signal corresponding to channel 4.

[0113] Two sub-optical signals corresponding to the same channel are respectively input to the input interfaces of two corresponding photodetectors 300 in the same group of photodetectors 300, and are converted into corresponding electrical signals and output from the output interfaces of the two photodetectors 300. The output interfaces of the two photodetectors 300 in the same group of photodetectors 300 are coupled to the same node (e.g., N1) so that the node outputs a superimposed current signal, which serves as the photodetection response of the corresponding channel.

[0114] Based on the overall response of the wave demultiplexing receivers corresponding to channel A and channel B, it can be seen that, by adopting the technical solution provided in the embodiments of this application, the actual response spectrum of each channel has the advantages of large channel bandwidth and low insertion loss. Figure 13C In the diagram, the "dashed line" represents the standard response spectrum for each channel, and the "solid line" represents the actual response spectrum for each channel.

[0115] Example 5

[0116] Figure 14 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided in the fifth embodiment of this application.

[0117] like Figure 14 As shown, the functional block diagram of the on-chip integrated wavelength demultiplexing receiver structure and the subsequent conversion to the corresponding electrical signals are similar to those in Embodiment 2. The only difference is that, for each channel, after demultiplexing by the first-stage wavelength demultiplexer, the first and second sub-optical signals corresponding to that channel are not separate but partially overlap. Taking the channel corresponding to wavelength λ1 as an example, a portion of the light in the center band λ1C of wavelength λ1 will be input as one path to a second-stage wavelength demultiplexer 220 along with λ1A, and another portion of the light in the center band λ1C of wavelength λ1 will be input as another path to another second-stage wavelength demultiplexer 220 along with λ1B. The wavelength demultiplexing process for the other channels corresponding to wavelengths λ2, λ3, and λ4 is similar and will not be described in detail here.

[0118] Specifically, taking an input light containing four CWDM channels with wavelengths λ1, λ2, λ3, and λ4 as an example, where λ1, λ2, λ3...λ4 are arranged in ascending or descending order of their center wavelengths. The input light first enters the input port of the first-stage wavelength demultiplexer 210. After passing through the first-stage wavelength demultiplexer 210, the input light is split into two paths and output from the two output ports of the first-stage wavelength demultiplexer 210 respectively. When the input light wavelengths are λ1C, λ2C, λ3C, and λ4C (where λ1C, λ2C, λ3C, and λ4C correspond to the center bands of λ1, λ2, λ3, and λ4 respectively), λ1C, λ2C, λ3C, and λ4C will be simultaneously output from their respective corresponding output ports of different second-stage wavelength demultiplexers 220. The first optical signal contains four wavelengths (first sub-optical signals): λ1A+λ1C, λ2A+λ2C, λ3A+λ3C, and λ4A+λ4C. The second optical signal contains four wavelengths (second sub-optical signals): λ1B+λ1C, λ2B+λ2C, λ3B+λ3C, and λ4B+λ4C. In this case, for each channel, the wavelengths of the first sub-optical signals in the first optical signal and the second sub-optical signals in the second optical signal partially overlap within the corresponding channel.

[0119] Example 6

[0120] Figure 15 This is a functional block diagram of an on-chip integrated wave demultiplexer receiver structure provided for the sixth embodiment of this application. Figure 16 This is a functional block diagram of another on-chip integrated wave demultiplexer receiver structure provided in the sixth embodiment of this application.

[0121] like Figure 15 , Figure 16 As shown, the functional block diagram of the on-chip integrated wavelength demultiplexing receiver structure and the subsequent conversion to the corresponding electrical signal are similar to those in Embodiment 3. The only difference is that, for each channel, after demultiplexing by the first-stage wavelength demultiplexer, the two optical signals corresponding to that channel are not separate from each other, but overlap in the center band. Taking the channel corresponding to wavelength λ1 as an example, a portion of the light in the center band λ1C of wavelength λ1 will be input as one light into a second-stage wavelength demultiplexer 220 along with λ1A, and another portion of the light in the center band λ1C of wavelength λ1 will be input as another light into another second-stage wavelength demultiplexer 220 along with λ1B. The wavelength demultiplexing process for the other channels corresponding to wavelengths λ2, λ3, and λ4 is similar and will not be described in detail here. At this time, for each channel, the band of the first sub-optical signal in the first optical signal and the band of the second sub-optical signal in the second optical signal partially overlap within the corresponding channel.

[0122] Specifically, taking an input light containing four CWDM channels with wavelengths λ1, λ2, λ3, and λ4 as an example, where λ1, λ2, λ3...λ4 are arranged in ascending or descending order of their center wavelengths. In this embodiment, λ1, λ2, λ3, and λ4 respectively include two polarization modes: TE and TM. The input light first enters the polarization beam splitter rotator 230. After being processed by the polarization beam splitter rotator 230, the input light is split into two paths and output from the two output ports of the polarization beam splitter rotator. One path contains optical signals of four wavelengths (λ1, λ2, λ3, and λ4) in the TE polarization mode, and the other path contains optical signals of four wavelengths (λ1, λ2, λ3, and λ4) in the TM polarization mode. The input light containing TE polarization modes λ1, λ2, λ3, and λ4 and the input light containing TM polarization modes λ1, λ2, λ3, and λ4 are respectively input to different input ports of the first-stage wavelength demultiplexer 210.

[0123] Specifically, the input light containing TE polarization states λ1, λ2, λ3, and λ4 is split into two paths after passing through the first-stage wavelength demultiplexer 210 and output from the two output ports of the first-stage wavelength demultiplexer 210. The first optical signal is TE polarized and contains four sub-optical signals (first sub-optical signals) with wavelengths λ1A+λ1C, λ2A+λ2C, λ3A+λ3C, and λ4A+λ4C. The second optical signal is TE polarized and contains four sub-optical signals (second sub-optical signals) with wavelengths λ1B+λ1C, λ2B+λ2C, λ3B+λ3C, and λ4B+λ4C. The number of sub-optical signals in the first and second optical signals is the same, and each corresponds to one of the four channels.

[0124] The first and second optical signals in TE polarization state are input to the input ports of the first and second-stage wavelength demultiplexer A and the second and second-stage wavelength demultiplexer B, respectively. Specifically, the first optical signal in TE polarization state (λ1A+λ1C, λ2A+λ2C, λ3A+λ3C, λ4A+λ4C) is input to the first and second-stage wavelength demultiplexer A and split into four paths, which are output from the four output ports of the first and second-stage wavelength demultiplexer A, corresponding to the four wavelengths λ1A+λ1C, λ2A+λ2C, λ3A+λ3C, and λ4A+λ4C, respectively; the second optical signal in TE polarization state (λ1B+λ1C, λ2B+λ2C, λ3B+λ3C, λ4B+λ4C) is input to the second and second-stage wavelength demultiplexer B and split into four paths, which are output from the four output ports of the first and second-stage wavelength demultiplexer A, respectively. The light is divided into four paths and output from the four output ports of the second-stage wavelength demultiplexer B, corresponding to the four wavelengths λ1B+λ1C, λ2B+λ2C, λ3B+λ3C, and λ4B+λ4C, respectively. After passing through the first-stage wavelength demultiplexer A and the second-stage wavelength demultiplexer B, the light in the TE polarization state is divided into a total of eight paths, corresponding to the sub-optical signals with wavelengths λ1A+λ1C, λ2A+λ2C, λ3A+λ3C, and λ4A+λ4C, and the sub-optical signals with wavelengths λ1B+λ1C, λ2B+λ2C, λ3B+λ3C, and λ4B+λ4C, respectively.

[0125] The process of input light containing TM polarization states λ1, λ2, λ3, and λ4 passing through the first-stage wave demultiplexer 210 is similar to the process of input light containing TE polarization states λ1, λ2, λ3, and λ4 passing through the first-stage wave demultiplexer 210, and will not be described again here.

[0126] This application also proposes a chip that includes the on-chip integrated wavelength demultiplexer receiver structure of any of the foregoing embodiments.

[0127] The on-chip integrated wavelength demultiplexing receiver structure and chip provided in this application embodiment includes a wavelength demultiplexing module and photodetectors. The wavelength demultiplexing module includes a cascaded first-stage wavelength demultiplexer and a second-stage wavelength demultiplexer. The aim is to demultiplex a single original optical multiplexed signal containing N channels into N first sub-optical signals and N second sub-optical signals using the wavelength demultiplexing module. Then, at least two sub-optical signals from the same channel are respectively input to the corresponding photodetectors in the same group of photodetectors to be converted into corresponding electrical signals and output. Finally, all electrical signals output from the same group of photodetectors are configured as a superimposed output to serve as the optical detection output for the corresponding channel. Compared to commonly used technologies, the on-chip integrated wavelength demultiplexing receiver structure of this application not only achieves large channel bandwidth, low insertion loss, and low crosstalk, but also achieves accurate monitoring of the intensity of the optical signals in each channel.

[0128] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0129] The on-chip integrated wavelength division multiplexing receiver structure and chip provided in this application have been described in detail above with reference to the embodiments. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An on-chip integrated wave demultiplexing receiver structure, characterized in that, It includes a wave demultiplexing module and multiple sets of photodetectors. The wave demultiplexing module includes a cascaded first-stage wave demultiplexer and a second-stage wave demultiplexer. The first-stage wave demultiplexer has one input port and two output ports, and the second-stage wave demultiplexer has one input port and N output ports. The second-stage wave demultiplexer includes a first-stage wave demultiplexer and a second-stage wave demultiplexer. The two output ports of the first-stage wave demultiplexer are optically connected to the input ports of the first-stage wave demultiplexer and the second-stage wave demultiplexer, respectively, where N is a positive integer greater than 1. The first-stage wavelength demultiplexer is used to demultiplex a single original optical multiplexed signal containing N channels received at an input port, and decompose the optical signal of each channel into a first sub-optical signal and a second sub-optical signal according to the wavelength band. The first sub-optical signal of the N channels after demultiplexing is input to the input port of the first-stage wavelength demultiplexer, and the second sub-optical signal of the N channels after demultiplexing is input to the input port of the second-stage wavelength demultiplexer. The first and second-stage wavelength division multiplexers demultiplex the received N channels of first sub-optical signals into N first sub-optical signals, and output the N first sub-optical signals from the N output ports of the first and second-stage wavelength division multiplexers respectively; the second and second-stage wavelength division multiplexers demultiplex the received N channels of second sub-optical signals into N second sub-optical signals, and output the N second sub-optical signals from the N output ports of the second and second-stage wavelength division multiplexers respectively. One group of photodetectors is connected to one of the output ports of the first and second stage wave demultiplexers and one of the output ports of the second stage wave demultiplexer. The same group of photodetectors is configured to convert the received sub-optical signals from the same channel into corresponding electrical signals and output them. All electrical signals output by the same group of photodetectors are configured to be superimposed and output as the optical detection output of the corresponding channel.

2. The on-chip integrated wave demultiplexing receiver structure according to claim 1, characterized in that, For each channel, the center wavelength of the first sub-optical signal band is smaller than the center wavelength of the second sub-optical signal band.

3. The on-chip integrated wave demultiplexing receiver structure according to claim 2, characterized in that, For each channel, the bands of the first sub-optical signal and the second sub-optical signal partially overlap within the corresponding channel.

4. The on-chip integrated wave demultiplexing receiver structure according to claim 1, characterized in that, A set of photodetectors includes at least two photodetectors, each of the at least two photodetectors having an input interface and an output interface, which is used to convert a sub-optical signal received at an input interface into a corresponding electrical signal and output it from the output interface.

5. The on-chip integrated wave demultiplexing receiver structure according to claim 4, characterized in that, All photodetectors in the same group are arranged in parallel and adjacent to each other, so as to convert the received sub-optical signals into corresponding electrical signals and output them respectively; The output interfaces of all photodetectors in a group of photodetectors are coupled to the same node so that all electrical signals are superimposed and output through the node.

6. The on-chip integrated wave demultiplexing receiver structure according to claim 1, characterized in that, A set of photodetectors includes at least one photodetector, each of the at least one photodetector having two input interfaces and one output interface, which is used to convert two sub-optical signals received from the two input interfaces into two corresponding electrical signals, and generate a combined electrical signal and output it from the output interface.

7. The on-chip integrated wave demultiplexing receiver structure according to claim 6, characterized in that, The two input interfaces of each photodetector are located on both sides of the photodetector to convert the two received sub-optical signals into corresponding electrical signals and output them.

8. The on-chip integrated wave demultiplexing receiver structure according to claim 7, characterized in that, A set of photodetectors includes at least two photodetectors. All photodetectors in the same group are arranged in parallel and adjacent to each other, so as to convert the received at least four sub-optical signals into two corresponding combined electrical signals and output them from the corresponding output interface. The output interfaces of all photodetectors in a group of photodetectors are coupled to the same node so that the two combined electrical signals are superimposed and output through the node.

9. The on-chip integrated wave demultiplexing receiver structure according to claim 1, characterized in that, The second-stage wave demultiplexer is a flat-top wave demultiplexing structure, which is used to demultiplex a single optical signal received from one input port into at least two sub-optical signals with flat-top bandwidth, and output the at least two sub-optical signals from at least two output ports respectively. The flat-top wave decomposition and multiplexing structure includes any one of the following: etched diffraction grating structure, arrayed waveguide grating structure, Mach-Zehnder interference structure, and reflective grating structure.

10. The on-chip integrated wave demultiplexer receiver structure according to any one of claims 1 to 9, characterized in that, The wave demultiplexing module also includes a polarization beam splitter, which is used to convert the received original optical multiplexed signal into a first set of optical multiplexed signals and a second set of optical multiplexed signals with mutually perpendicular polarization states. The first set of optical multiplexed signals and the second set of optical multiplexed signals are respectively input to the input ports corresponding to different first-stage wavelength demultiplexers.

11. The on-chip integrated wave demultiplexing receiver structure according to claim 1, characterized in that, It also includes multiple transimpedance amplifiers, Each transimpedance amplifier is configured to be coupled to the output interface of each photodetector in the same group of photodetectors to convert the received superimposed electrical signal into a corresponding voltage signal.

12. A chip, characterized in that, Includes the on-chip integrated wave demultiplexer receiver structure as described in any one of claims 1-11.

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