On-chip integrated optical coupling light splitting structure and photon integrated circuit chip

Abstract

The invention discloses an on-chip integrated optical coupling light splitting structure and a photon integrated circuit chip. The optical coupling light splitting structure comprises a first light input structure, two second light input structures, a light splitting structure and four channels. Wherein the light splitting structure comprises a first-stage light splitter, a first second-stage light splitter and a second second-stage light splitter. The first optical input structure is connected to a first input port of the first-stage optical splitter, and the two second optical input structures are respectively connected to second input ports of the first second-stage optical splitter and the second second-stage optical splitter. According to the first optical signal input to the first optical input structure or the second optical signals input to the two second optical input structures, the effect of dividing one beam of light into four parts or dividing two beams of light into two parts respectively can be flexibly achieved. In addition, the four channels can output light meeting preset conditions. Complex equipment adjustment or feedback is not needed, and the use complexity of the system is simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical communication technology, in particular to an on-chip integrated optical coupling splitting structure and a photonic integrated circuit chip. BACKGROUND

[0002] With the explosion of Internet applications such as video, live broadcast, and AI, the demand for communication rate and communication capacity of data centers is also growing rapidly. With the increase of optical communication module rate, the rate of a single channel is limited by high-speed optical chips and devices, and cannot be continuously increased. Therefore, multi-channel parallelism has become the main means to expand communication capacity. In current 100G / 400G / 800G / 1.6T optical modules, a multi-channel parallel scheme is adopted. Silicon optical chips have been widely used in current optical communication modules due to their high integration, high yield, and high productivity.

[0003] However, due to the characteristics of the indirect band gap of silicon material, silicon material itself does not emit light, so an external laser is needed to provide a light source for the silicon optical chip when used in an optical communication module. The current single laser chip can achieve a strong continuous light output intensity, so the light source is usually divided into multiple paths on the silicon optical chip by a splitter to provide a light source for multiple channels. The splitter on the current silicon optical chip can be divided into a passive scheme and an active scheme, wherein the passive scheme usually adopts a 3-port / 4-port 3dB splitter, and the active scheme usually adopts a Mach-Zehnder interferometer splitter. Once the chip is completed, the splitting ratio of the former is determined and cannot be flexibly changed. Although the latter can flexibly adjust the splitting ratio, it needs to be monitored in real time during the operation of the chip, which increases the complexity of the chip usage. SUMMARY

[0004] The present application aims to provide an on-chip integrated optical coupling splitting structure and a multi-channel photonic integrated circuit chip to solve the problems in the prior art. It has the following advantages: the on-chip integrated optical coupling splitting structure can flexibly realize splitting without the need for complex equipment adjustment or feedback, and simplifies the system usage complexity.

[0005] According to one aspect of the present application, an on-chip integrated optical coupling splitting structure is provided, comprising:

[0006] A first optical input structure and two second optical input structures are respectively used to receive a first optical signal and a second optical signal, wherein the first optical signal and the second optical signal are signals with different optical powers;

[0007] a first light input structure, a second light input structure, a first light output structure, and a second light output structure, wherein the first light input structure is optically connected to one first input port of the first-level optical splitter, the second light input structure is optically connected to another first input port of the first-level optical splitter, the first light output structure is optically connected to one of the at least two first output ports of the first-level optical splitter, and the second light output structure is optically connected to another of the at least two first output ports of the first-level optical splitter;

[0008] 4 channels, wherein 2 channels are connected to the two second output ports of the first second-level optical splitter respectively, and the other 2 channels are connected to the two second output ports of the second second-level optical splitter respectively;

[0009] the first light input structure is optically connected to one first input port of the first-level optical splitter, and the two second light input structures are optically connected to another of the at least two second input ports of the first second-level optical splitter and the second second-level optical splitter respectively;

[0010] the first-level optical splitter divides the first light signal input from the first light input structure into two paths and inputs into the first second-level optical splitter and the second second-level optical splitter respectively, the first second-level optical splitter and the second second-level optical splitter divide the light signal received by each of them into two sub-light signals respectively and output to the corresponding 4 channels;

[0011] Alternatively, the first second-level optical splitter and the second second-level optical splitter divide the second light signal input from the two second light input structures into two sub-light signals respectively and output to the corresponding 2 channels respectively.

[0012] In some embodiments, the optical power of the first light signal received by the first light input structure is greater than the optical power of the second light signal received by the second light input structure.

[0013] In some embodiments, the first-level optical splitter comprises any one of an MMI multi-mode interferometer, a three-pronged optical splitter, an adiabatic coupler, and a directional coupler;

[0014] The first second-level optical splitter and the second second-level optical splitter each comprise any one of an MMI multi-mode interferometer, a three-pronged optical splitter, an adiabatic coupler, and a directional coupler.

[0015] In some embodiments, the splitting ratio of the first-level optical splitter, the first second-level optical splitter, and the second second-level optical splitter is 50:50.

[0016] In some embodiments, the first-level optical splitter has at least two first input ports;

[0017] One of the first input ports in the first-level optical splitter is configured to be idle or receive a first test input signal.

[0018] Further comprising a plurality of optical detectors, each of which is configured to be connected with a corresponding one of the channels to monitor the output of the corresponding channel.

[0019] In some embodiments, the first optical input structure comprises a first edge coupler; and the two second optical input structures comprise second edge couplers.

[0020] In some embodiments, the optical coupling and splitting structure comprises at least two splitting structures, two adjacent ones of the at least two splitting structures are cascaded with each other; wherein each of the at least two splitting structures is optically connected with a corresponding one of the first optical input structures and the two second optical input structures.

[0021] The optical coupling and splitting structure further comprises a zeroth-level optical splitter having at least one zeroth input port and at least two zeroth output ports,

[0022] The two zeroth output ports of the zeroth-level optical splitter are respectively connected with corresponding first input ports in two of the first-level optical splitters in two adjacent splitting structures.

[0023] In some embodiments, the optical coupling and splitting structure further comprises a third optical input structure for receiving a third optical signal;

[0024] The third optical input structure is connected with one of the zeroth input ports of the zeroth-level optical splitter, and the zeroth-level optical splitter is configured to split the third optical signal input from the third optical input structure into two paths and input into two of the first-level optical splitters in two adjacent splitting structures.

[0025] In some embodiments, the zeroth-level optical splitter has at least two zeroth input ports;

[0026] One of the zeroth input ports in the zeroth-level optical splitter is configured to be idle or receive a second test input signal.

[0027] According to yet another aspect of the present application, there is provided a photonic integrated circuit chip, comprising a substrate layer and a waveguide layer, the waveguide layer being provided with the aforementioned optical coupling and splitting structure.

[0028] In the on-chip integrated light coupling splitting structure and the photonic integrated circuit chip provided by the embodiment of the present application, the light coupling splitting structure comprises a first light input structure, two second light input structures, a light splitting structure and four channels. The light splitting structure comprises a first light splitter, a first second light splitter and a second second light splitter. The first light input structure is connected to a first input port of the first light splitter, and the two second light input structures are respectively connected to second input ports of the first second light splitter and the second second light splitter. The light coupling splitting structure can flexibly realize the effect of splitting one light beam into four or splitting two light beams each into two according to a first light signal input to the first light input structure or a second light signal input to the two second light input structures. Moreover, the four channels can all output light meeting preset conditions. Compared with the common technology, the system complexity is simplified without complex equipment adjustment or feedback. BRIEF DESCRIPTION OF DRAWINGS

[0029] The technical scheme and other beneficial effects of the present application will be apparent from the following detailed description of the specific embodiments of the present application with reference to the accompanying drawings.

[0030] Figure 1 An example one structure schematic diagram of an on-chip passive light splitting structure of a multi-channel silicon optical chip in the common technology.

[0031] Figure 2 An example two structure schematic diagram of an on-chip passive light splitting structure of a multi-channel silicon optical chip in the common technology.

[0032] Figure 3 An example one structure schematic diagram of an on-chip active light splitting structure of a multi-channel silicon optical chip in the common technology.

[0033] Figure 4 A structure schematic diagram of the on-chip integrated light coupling splitting structure provided by the embodiment one of the present application.

[0034] Figure 5 A structure schematic diagram of the on-chip integrated light coupling splitting structure provided by the embodiment two of the present application.

[0035] Figure 6A A structure schematic diagram of another on-chip integrated light coupling splitting structure provided by the embodiment two of the present application. Figure 1 .

[0036] Figure 6B A structure schematic diagram of another on-chip integrated light coupling splitting structure provided by the embodiment two of the present application. Figure 2 .

[0037] Figure 6C A structure schematic diagram of another on-chip integrated light coupling splitting structure provided by the embodiment two of the present application. Figure 3 .

[0038] Figure 7 A structure diagram of an on-chip integrated light coupling and splitting structure provided in Embodiment Three of the present application.

[0039] Figure 8 A structure diagram of an on-chip integrated light coupling and splitting structure provided in Embodiment Four of the present application.

[0040] Figure 9 A structure diagram of another on-chip integrated light coupling and splitting structure provided in Embodiment Five of the present application.

[0041] Main reference signs:

[0042] 110, first light input structure; 120, second light input structure; 130, third light input structure;

[0043] 200, light splitting structure; 210, first stage light splitter; 220A, first second stage light splitter; 220B, second second stage light splitter;

[0044] 310, zero stage light splitter;

[0045] 400, light detector. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative work fall within the scope of protection of the present application.

[0047] The terms “first”, “second” in the specification are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with “first”, “second” can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of “multiple” is two or more, unless otherwise specifically limited.

[0048] In the description of the present application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, or electrical connection or can communicate with each other; can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0049] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, reference numerals and / or reference letters can be repeated in different examples in the present application, and such repetition is for the purpose of simplification and clarity, and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0050] At present, the structure of the on-chip passive optical splitting structure of the multi-channel silicon optical chip in the commonly used technology is as shown in Figure 1 and Figure 2 If the structure of Figure 1 is used, 1 laser can provide light sources for 2 channels. If the structure of Figure 2 is used, 1 laser can provide light sources for 4 channels. As can be seen, the number of channels that 1 laser provides light sources is determined when the chip is designed and processed, and cannot be flexibly adjusted according to the performance of the laser, silicon optical chip and customer demand afterwards.

[0051] Figure 3 An exemplary structure diagram of the on-chip active optical splitting structure of the multi-channel silicon optical chip in the commonly used technology is shown.

[0052] As shown in Figure 3 , when 1 laser enters the silicon optical chip from the coupler 1, and the splitting ratio of the tunable optical splitter is 1:1, 1 laser can provide light sources for 4 channels. When 2 lasers enter the silicon optical chip from the coupler 1 and the coupler 2 respectively, and the splitting ratio of the tunable optical splitter is 1:0, 2 lasers can provide light sources for 4 channels. Each laser provides light sources for 2 channels. The problem of the above scheme is: ① the tunable optical splitter needs to be in the power-on state at any time when the chip is working; ② the working point of the tunable optical splitter needs to be controlled in real time through feedback to ensure that the splitting ratio matches the target value. As can be seen, this scheme increases the complexity of the use of the entire system and increases the power consumption.

[0053] Embodiment one

[0054] Figure 4 FIG. 1 is a schematic diagram of a structure of an on-chip integrated light coupling splitting junction according to an embodiment of the present application.

[0055] Referring to Figure 4 The embodiment one of the present application provides an on-chip integrated light coupling splitting structure, comprising: a first light input structure 110, two second light input structures 120, a splitting structure 200 and four channels.

[0056] The first light input structure 110 and the two second light input structures 120 are respectively used for receiving a first light signal and a second light signal. The first light signal and the second light signal are signals of different optical powers.

[0057] The splitting structure 200 comprises a first-stage splitter 210, a first second-stage splitter 220A and a second second-stage splitter 220B. The first-stage splitter 210 has at least one first input port 211 and at least two first output ports 212, and the first second-stage splitter 220A and the second second-stage splitter 220B each have at least two second input ports 221 and at least two second output ports 222. One of the two first output ports 212 of the first-stage splitter 210 is optically connected with one of the at least two second input ports 221 of the first second-stage splitter 220A, and the other is optically connected with one of the at least two second input ports 221 of the second second-stage splitter 220B.

[0058] Two of the four channels are respectively connected with the two second output ports 222 of the first second-stage splitter 220A, and the other two channels are respectively connected with the two second output ports 222 of the second second-stage splitter 220B.

[0059] The first light input structure 110 is optically connected with one first input port 211 of the first-stage splitter 210, and the two second light input structures 120 are respectively optically connected with the other of the at least two second input ports 221 of the first second-stage splitter 220A and the second second-stage splitter 220B.

[0060] The first-stage splitter 210 splits the first light signal input from the first light input structure 110 into two paths and inputs them into the first second-stage splitter 220A and the second second-stage splitter 220B respectively, the first second-stage splitter 220A and the second second-stage splitter 220B each splits the received light signal into two sub-light signals and outputs them to the corresponding four channels (channel 1, channel 2, channel 3 and channel 4).

[0061] Alternatively, the first second-level optical splitter 220A and the second second-level optical splitter 220B respectively output two sub-optical signals to the corresponding two channels after splitting the second optical signal input from the two second optical input structures 120.

[0062] In actual applications, the first optical input structure 110 can be selected to input the first optical signal to achieve splitting one first optical signal into four, thereby providing the required light source for the four channels. Alternatively, the two second optical input structures 120 can be selected to simultaneously input the second optical signal to achieve splitting two second optical signals into two, thereby providing the required light source for the four channels.

[0063] The on-chip integrated optical coupling and splitting structure provided by the embodiment of the present application includes the first optical input structure 110, the two second optical input structures 120, the optical splitting structure 200, and the four channels. The optical splitting structure 200 includes the first-level optical splitter 210, the first second-level optical splitter 220A, and the second second-level optical splitter 220B. The first optical input structure 110 is connected to the first input port 211 of the first-level optical splitter 210, and the two second optical input structures 120 are respectively connected to the second input ports 221 of the first second-level optical splitter 220A and the second second-level optical splitter 220B. The optical coupling and splitting structure can flexibly achieve the effect of splitting one light into four or splitting two lights into two according to the first optical signal input to the first optical input structure 110 or the second optical signal input to the two second optical input structures 120, and the four channels can all output light meeting the preset conditions. Compared with the conventional technology, the system complexity is simplified without the need for complex equipment adjustment or feedback.

[0064] In the embodiment of the present application, the first optical input structure 110 is used for optical coupling and interfacing with the first laser to receive the first optical signal emitted by the first laser, and the second optical input structure 120 is used for optical coupling and interfacing with the second laser to receive the second optical signal emitted by the second laser. The optical power of the first optical signal emitted by the first laser is greater than the optical power of the second optical signal emitted by the second laser.

[0065] Exemplarily, when the first light signal is input, the first light input structure 110 is selected, and the first light signal is divided into four by a first-level optical splitter 210, a first second-level optical splitter 220A and a second second-level optical splitter 220B, and the first light signal is evenly divided into channel 1, channel 2, channel 3 and channel 4. When the second light signal is input, the two second light input structures 120 are selected, and the two second light signals are respectively divided into two by the first second-level optical splitter 220A and the second second-level optical splitter 220B, wherein one second light signal is evenly divided into channel 1 and channel 2, and the other second light signal is evenly divided into channel 3 and channel 4. Thus, the external laser (the first laser or the second laser) can be coupled with the first light input structure 110 or the two second light input structures 120 according to the output optical power of the external laser. For example, if the optical power of the light signal emitted by the external laser is large (for example, the first light signal), the external laser can be used as the first laser. If the optical power of the light signal emitted by the external laser is small (for example, the second light signal), the external laser can be used as the second laser.

[0066] Exemplarily, the first light input structure 110 and the two second light input structures 120 each include an edge coupler. The edge coupler has the advantages of high coupling efficiency and wide working bandwidth.

[0067] Specifically, the first light input structure 110 includes a first edge coupler, and the two second light input structures 120 include two second edge couplers. The first edge coupler is coupled with the first laser to receive the first light signal. The two second edge couplers are respectively coupled with the corresponding second lasers to respectively receive the second light signal.

[0068] In some embodiments, the first-level optical splitter 210 is a 3dB optical splitter, and the 3dB optical splitter includes any one of an MMI (Multi-Mode Interferometer), a 3-dB splitter, an adiabatic coupler and a directional coupler. The above devices can all achieve the function of dividing one input light into two output lights. Exemplarily, the first-level optical splitter 210 is a 2*4 MMI, wherein 2 is the number of input ports and 4 is the number of output ports. Exemplarily, the first-level optical splitter 210 is a 4*4 MMI, wherein 4 is the number of input ports and 4 is the number of output ports.

[0069] The first second-level optical splitter 220A and the second second-level optical splitter 220B are both 3dB optical splitters, and the 3dB optical splitter includes any one of an MMI (Multi-Mode Interferometer), a 3-dB splitter, an adiabatic coupler and a directional coupler. The above devices can all achieve the function of dividing one input light into two output lights. Exemplarily, the first second-level optical splitter 220A and the second second-level optical splitter 220B are both 2*4 MMIs,

[0070] Where 2 represents the number of input ports and 4 represents the number of output ports. For example, both the first and second stage splitters 220A and 220B are 4*4 MMIs, where 4 represents the number of input ports and 4 represents the number of output ports.

[0071] Furthermore, to ensure energy balance in the output of each channel and to make the optical power of each channel similar, thus guaranteeing that the light sources in each channel after beam splitting can operate normally, the splitting ratio of the first-stage beam splitter 210, the first-second-stage beam splitter 220A, and the second-second-stage beam splitter 220B is 50:50. That is, the two first output ports 212 of the first-stage beam splitter 210 have a splitting ratio of 50:50, for example. The two second output ports 222 of the first-second-stage beam splitter 220A have a splitting ratio of 50:50, for example. The two second output ports 222 of the second-second-stage beam splitter 220B have a splitting ratio of 50:50, for example.

[0072] Example 2

[0073] Figure 5 This is a schematic diagram of an on-chip integrated optical coupling beam splitter structure provided in Embodiment 2 of this application. Figure 6A This is a schematic diagram of another on-chip integrated optical coupling beam splitter structure provided in Embodiment 2 of this application. Figure 1 . Figure 6B This is a schematic diagram of another on-chip integrated optical coupling beam splitter structure provided in Embodiment 2 of this application. Figure 2 . Figure 6C This is a schematic diagram of another on-chip integrated optical coupling beam splitter structure provided in Embodiment 2 of this application. Figure 3 .

[0074] Please see Figure 5 , Figure 6A - Figure 6C Compared to Embodiment 1, in this embodiment, the first-stage beam splitter 210 has at least two first input ports 211.

[0075] For example, such as Figure 5 As shown, a first input port 211 in the first-stage splitter 210 is configured to be idle.

[0076] For example, such as Figure 6A As shown, a first input port 211 in the first-stage beam splitter 210 is configured to receive a first test input signal. This first test input signal can be an optical test signal. For example, Figure 6A In the first stage, a first input port 211 of the first-stage beam splitter 210 is connected to the grating coupler 510 to receive optical test signals.

[0077] Further, the light coupling and splitting structure of the embodiment of the present application further comprises a plurality of light detectors 400, each of which is configured to be connected with a corresponding channel, for example, channel 1, channel 2, channel 3 and channel 4 are respectively connected to corresponding light detectors 400 to monitor the output of the corresponding channel. Exemplarily, the light detector 400 is usually composed of a light-sensitive element (such as a photodiode, a photomultiplier tube, a photoresistor, etc.) and related electronic elements. The light-sensitive element will generate a current or voltage output after receiving the light signal, which is proportional to the intensity or power of the light of the corresponding channel.

[0078] It should be understood that in some other embodiments, for example, as shown in Figure 6B , a light splitting device can also be provided between the channel and the light detector. Alternatively, as shown in Figure 6C , a light splitting device is also provided before the output of the corresponding channel, which is respectively connected with the light detector and the corresponding channel.

[0079] Embodiment three

[0080] Figure 7 The structure diagram of the on-chip integrated light coupling and splitting structure provided by the embodiment three of the present application.

[0081] Compared with the embodiment one, in the present embodiment, the light coupling and splitting structure comprises at least two light splitting structures 200. Adjacent two light splitting structures 200 in the at least two light splitting structures 200 are cascaded with each other. Wherein, each light splitting structure 200 in the at least two light splitting structures 200 is optically connected with a corresponding first light input structure 110 and two second light input structures 120.

[0082] Exemplarily, as shown in Figure 7 , taking the light coupling and splitting structure comprising two light splitting structures 200 as an example, at this time, the two light splitting structures 200 can provide light sources for 8 channels. It should be understood that in other embodiments, three light splitting structures 200 or more light splitting structures 200 can also be used to provide light sources for 12 channels or more channels, which will not be described herein again.

[0083] Exemplarily, in the present embodiment of the present application, the light coupling and splitting structure further comprises a zeroth-order light splitter 310, the zeroth-order light splitter 310 has at least one zeroth-order input port 311 and at least two zeroth-order output ports 312, two zeroth-order output ports 312 of the zeroth-order light splitter 310 are respectively connected with corresponding first input ports 211 in two first-order light splitters 210 in adjacent two light splitting structures 200. Exemplarily, the zeroth-order light splitter 310 is a 3dB light splitter, which includes any one of an MMI multi-mode interferometer, a three-pronged light splitter, an adiabatic coupler and a directional coupler.

[0084] Further, the splitting ratio of the zeroth-order splitter 310 is 50:50. That is, the splitting ratio between the two zeroth output ports 312 of the zeroth-order splitter 310 is, for example, 50:50. Thus, the received third optical signal is equally divided into the corresponding first input ports 211 of the two first-order splitters 210 in the adjacent two optical splitting structures 200.

[0085] Further, the optical coupling splitting structure further comprises a third optical input structure 130 for receiving a third optical signal. The third optical input structure 130 is connected to the zeroth input port 311 of the zeroth-order splitter 310. The zeroth-order splitter 310 is configured to split the third optical signal input from the third optical input structure 130 into two paths and input into the two first-order splitters 210 in the adjacent two optical splitting structures 200, respectively.

[0086] Specifically, the third optical input structure 130 is used for optical coupling with the third laser to receive the third optical signal emitted by the third laser. The power of the third optical signal is greater than the power of the first optical signal, and the power of the first optical signal is greater than the power of the second optical signal. When the powers of the two first optical signals are equal, the power of the third optical signal is equal to the sum of the powers of the two first optical signals. Or, when the powers of the four second optical signals are equal, the power of the third optical signal is equal to the sum of the powers of the four second optical signals, and in this case, the use of one third optical signal to input the on-chip integrated optical coupling splitting structure from the third optical input structure 130, the use of two first optical signals to input the on-chip integrated optical coupling splitting structure from two first optical input structures, and the use of four second optical signals to input the on-chip integrated optical coupling splitting structure from four second optical input structures, the optical powers of all channels (channels 1 to 8) finally reach equalization. Here, the optical powers of all channels are equal, which means that in the three use cases, the optical power of channel 1 is equal, and the optical power of all channels from channel 1 to channel 8 is also equal.

[0087] Further, the third optical input structure 130 comprises an edge coupler.

[0088] Embodiment Four

[0089] Figure 8 A structure diagram of an on-chip integrated optical coupling splitting structure provided in Embodiment Four of the present application.

[0090] Please refer to Figure 8 As shown, compared with Embodiment Three, in the present embodiment, the zeroth-order splitter 310 has at least two zeroth input ports. Among them, one zeroth input port 311 in the zeroth-order splitter 310 is configured to be idle.

[0091] In some embodiments, the light coupling and splitting structure can be used in a light emitting end. In which, the first light input structure 110 can be used to optically couple with a first laser to receive a first light signal emitted by the first laser. The second light input structure 120 can be used to optically couple with a second laser to receive a second light signal emitted by the second laser. The third light input structure 130 can be used to optically couple with a third laser to receive a third light signal emitted by the third laser. The first light signal, the second light signal, or the third light signal is then split by the two splitting structures 200 respectively to the corresponding plurality of channels, and finally output to an external optical fiber via the plurality of channels.

[0092] Embodiment Five

[0093] Figure 9 Another structure diagram of an on-chip integrated light coupling and splitting structure is provided in Embodiment Five of the present application. Please refer to Figure 9 As shown, compared with Embodiment Three, in the present embodiment, the zeroth-order splitter 310 has at least two zeroth input ports. In which, one of the zeroth input ports 311 of the zeroth-order splitter 310 is configured to receive a second test input signal. In which, the second test input signal can be an optical test signal. For example, one of the zeroth input ports 311 of the zeroth-order splitter 310 is connected with the grating coupler 510 to receive the optical test signal.

[0094] Further, a plurality of light detectors 400 are also included, each of which is configured to be connected with a corresponding channel to monitor the output of the corresponding channel. Exemplarily, the light detector 400 is usually composed of a light sensitive element (such as a photodiode, a photomultiplier tube, a photoresistor, etc.) and related electronic elements, which will generate a current or voltage output after receiving the light signal, which is proportional to the intensity or power of the light of the corresponding channel. It should be understood that in some other embodiments, for example, a splitting device can also be arranged between the channel and the light detector. Alternatively, a splitting device is arranged before the output of the corresponding channel, which is respectively connected with the light detector and the corresponding channel.

[0095] In some embodiments, the light coupling and splitting structure can be used in a light receiving end. In which, the light coupling and splitting structure inputs the light signal to the corresponding first light input structure 110, the second light input structure 120, or the third light input structure 130 through an external optical fiber. For example, the first light signal is input to the first light input structure 110, the second light signal is input to the second light input structure 120, and the third light signal is input to the third light input structure 130. Then the first light signal, the second light signal, or the third light signal is respectively split by the splitting structure 200 to the corresponding plurality of channels, and then input to the corresponding light detector 400, and finally the received light signal is converted into an electrical signal by the light detector 400 and parsed out.

[0096] The application also provides a photonic integrated circuit chip, comprising a substrate layer and a waveguide layer, wherein the waveguide layer is provided with the light coupling and splitting structure according to any one of the preceding embodiments.

[0097] In addition, the photonic integrated circuit chip has a first end surface for coupling with external light. The first light input structure 110 and the two second light input structures 120 are all optically coupled with the external environment from the first end surface.

[0098] In the on-chip integrated light coupling and splitting structure and the photonic integrated circuit chip provided in the embodiments of the application, the light coupling and splitting structure comprises a first light input structure, two second light input structures, a light splitting structure and four channels, wherein the light splitting structure comprises a first-stage light splitter, a first second-stage light splitter and a second second-stage light splitter. The first light input structure is connected to a first input port of the first-stage light splitter, and the two second light input structures are respectively connected to second input ports of the first second-stage light splitter and the second second-stage light splitter. The light coupling and splitting structure can flexibly realize the effect of splitting one light beam into four or splitting two light beams each into two according to a first light signal input to the first light input structure or a second light signal input to the two second light input structures, and the four channels can all output light meeting preset conditions. Compared with the conventional technology, the light coupling and splitting structure does not need complex equipment adjustment or feedback, and thus simplifies the use complexity of the system.

[0099] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0100] The on-chip integrated light coupling and splitting structure and the photonic integrated circuit chip provided in the application are described in detail above in combination with the embodiments. The principles and implementation manners of the application are described by applying specific examples in this paper, and the above embodiment descriptions are only used to help understand the technical solutions and core ideas of the application. Those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. An on-chip integrated light coupling and splitting structure, characterized by, Comprising: a first light input structure and two second light input structures for receiving a first light signal and a second light signal respectively, wherein the first light signal and the second light signal are signals of different optical power; a light splitting structure, the light splitting structure comprising a first level light splitter, a first second level light splitter and a second second level light splitter, the first level light splitter having at least one first input port and at least two first output ports, the first second level light splitter and the second second level light splitter each having at least two second input ports and at least two second output ports, one of the two first output ports of the first level light splitter being optically connected with one of the at least two second input ports of the first second level light splitter, and the other of the two first output ports of the first level light splitter being optically connected with one of the at least two second input ports of the second second level light splitter; four channels, two of which are connected with two second output ports of the first second level light splitter respectively, and the other two of which are connected with two second output ports of the second second level light splitter respectively; the first light input structure being optically connected with one first input port of the first level light splitter, and the two second light input structures being optically connected with the other of the at least two second input ports of the first second level light splitter and the second second level light splitter respectively; the first level light splitter splitting the first light signal input from the first light input structure into two paths and inputting into the first second level light splitter and the second second level light splitter respectively, the first second level light splitter and the second second level light splitter each splitting the light signal received by itself into two sub light signals and outputting into the corresponding four channels respectively; or, the first second level light splitter and the second second level light splitter each splitting the second light signal input from the two second light input structures into two sub light signals and outputting into the corresponding two channels respectively.

2. The on-chip integrated optical coupling light splitting structure of claim 1, wherein: the optical power of the first light signal received by the first light input structure is greater than the optical power of the second light signal received by the second light input structure.

3. The on-chip integrated optical coupling light splitting structure of claim 1, wherein: the first level light splitter comprises any one of an MMI (Multi-Mode Interferometer), a 1x3 splitter, an adiabatic coupler and a directional coupler; the first second level light splitter and the second second level light splitter each comprise any one of an MMI (Multi-Mode Interferometer), a 1x3 splitter, an adiabatic coupler and a directional coupler.

4. The on-chip integrated optical coupling light splitting structure of claim 3, wherein: the splitting ratio of the first level light splitter, the first second level light splitter and the second second level light splitter is 50:

50.

5. The on-chip integrated optical coupling light splitting structure of claim 3, wherein: the first level light splitter has at least two first input ports; one of the first input ports of the first level light splitter is configured to be idle or to receive a first test input signal.

6. The on-chip integrated optical coupling and splitting structure of claim 5, wherein, further comprising a plurality of optical detectors, Each of the light detectors is configured to be connected with the corresponding channel to monitor the output of the corresponding channel. 7.The on-chip integrated optical coupling and splitting structure of claim 1, wherein, the first optical input structure comprises a first edge coupler; two of the second optical input structures comprise a second edge coupler.

8. The integrated on-chip optical coupling and splitting structure of claim 1, wherein, The optical coupling and splitting structure comprises at least two splitting structures, and adjacent two of the at least two splitting structures are cascaded with each other. Each of the at least two splitting structures is optically connected with the corresponding first optical input structure and two of the second optical input structures. The optical coupling and splitting structure further comprises a zeroth-order splitter having at least one zeroth-order input port and at least two zeroth-order output ports, two of the zeroth-order output ports of the zeroth-order splitter are respectively connected with the corresponding first input ports of two of the first-order splitters in the adjacent two splitting structures.

9. The on-chip integrated optical coupling and splitting structure of claim 8, wherein, The optical coupling and splitting structure further comprises a third optical input structure for receiving a third optical signal; the third optical input structure is connected with one of the zeroth-order input ports of the zeroth-order splitter, and the zeroth-order splitter is configured to split the third optical signal input from the third optical input structure into two paths and input into two of the first-order splitters in the adjacent two splitting structures. 10.The on-chip integrated optical coupling and splitting structure of claim 8, wherein, the zeroth-order splitter has at least two zeroth-order input ports; one of the zeroth-order input ports of the zeroth-order splitter is configured to be idle or receive a second test input signal.

11. A photonic integrated circuit chip, characterized by comprising: a substrate layer and a waveguide layer, the waveguide layer being provided with the optical coupling and splitting structure according to any one of claims 1 to 10.

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