CN113873357A

CN113873357A - Optical splitter, ODN, method for identifying optical link where ONU is located, OLT, ONU and PON system

Info

Publication number: CN113873357A
Application number: CN202010614699.6A
Authority: CN
Inventors: 董小龙; 董振华; 董英华
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2021-12-31
Also published as: WO2022001230A1

Abstract

The invention discloses an optical splitter, an ODN, a method for identifying an optical link where an ONU is located, an OLT, the ONU and a PON system. The optical splitter comprises an incoming light section and N outgoing light sections, wherein each outgoing light section of at least N-1 outgoing light sections is provided with at least one optical filtering structure, and each optical filtering structure filters an optical signal with one wavelength by a specific transmissivity; any two light-emitting sections provided with the light filtering structures at least meet one of the following conditions: condition 1, at least one wavelength of the filtering is different; in condition 2, the transmittance for an optical signal of at least one wavelength is different. In the light-emitting section provided with the optical filtering structure, at least two light-emitting sections exist to satisfy the condition 2. The optical splitter is applied to the ODN of the PON, and the optical section can be identified through the wavelength or the transmissivity of the filtered optical signal, so that when the OLT side sends the optical link where the test optical detection ONU is located, the types of test light can be reduced, the test optical wavelength scanning range of the OLT is reduced, and the manufacturing difficulty and the cost of the device of the OLT sending the test light are reduced.

Description

Optical splitter, ODN, method for identifying optical link where ONU is located, OLT, ONU and PON system

Technical Field

The present invention relates to the field of optical communication, and more particularly, to an optical splitter, an ODN, a method for identifying an optical link in which an ONU is located in a PON system, an OLT, the ONU, and the PON system.

Background

In a Passive Optical Network (PON) system, an Optical Line Termination (OLT), an Optical Distribution Network (ODN) and an Optical Network Unit (ONU) are generally included, and the ODN provides an optical transmission physical channel between the OLT and the ONU.

ODNs generally include Optical Distribution Frames (ODFs), cable splice closures (also known as Splice and Splice Closures (SSCs)), cable Distribution closures (also known as Fiber Distribution Terminals (FDTs)), fiber Distribution closures (also known as Fiber Access Terminals (FATs)), fiber termination closures (also known as Access Terminal Boxes (ATBs)), and the like, where the FDTs may include splitters 1 and the FATs may include splitters 2. The optical signal from the OLT is split by the optical splitter 1 in the ODF, SSC, FDT, split by the optical splitter 2 in the FAT, and reach the ONU by the ATB in this order, that is, the optical signal from the OLT is transmitted to the ONU via the optical link between the OLT and the ONU. The optical splitter 1 equally divides the received optical signal power, one branch is transmitted to the optical splitter 2, then the optical splitter 2 equally divides the received optical signal power, and each branch is transmitted to the connected ONU. The output end of the last-stage optical splitter in the ODN is used as the output port of the ODN, and the ONU is connected to the output port of the ODN.

However, an operator or a Central Office (CO) cannot know which output port of the ODN each ONU is specifically connected to, that is, cannot know which optical link each ONU is specifically located on, or needs an installer to record on site to determine which output port of the ODN each ONU is specifically connected to (that is, on which optical link each ONU is specifically located), which is not only prone to error, but also has low efficiency and high labor cost.

Disclosure of Invention

In view of this, the present application provides an optical splitter, an ODN, a method for identifying an optical link where an ONU is located in a PON system, an OLT, the ONU, and the PON system, and aims to quickly and accurately detect the optical link where the ONU is located, and improve the efficiency of determining the optical link where the ONU is located.

In a first aspect, there is provided an optical splitter, comprising: the light source comprises an incident light section and N emergent light sections, wherein N is an integer greater than or equal to 2; each light-emitting section of the at least N-1 light-emitting sections is provided with at least one light filtering structure, and each light filtering structure filters light signals with one wavelength according to a specific transmissivity; any two light-emitting sections provided with the light filtering structures meet at least one of the following conditions 1 and 2: condition 1: at least one of the wavelengths filtered is different; condition 2: the transmittance of the optical signal for at least one wavelength is different. Wherein there are at least two of the light exit segments that satisfy the condition 2. The optical splitter is applied to the ODN of the PON, because the wavelengths of the filtered optical signals between the two light-emitting sections can be different, or the transmissivity of the same optical signal is different, the light sections can be distinguished through the wavelengths of the filtered optical signals, and can also be distinguished through the transmissivity of the same optical signal, so when the OLT side sends and tests the optical link where the optical detection ONU is located, the types of test light can be reduced to a great extent, the wavelength resources are saved, the test light wavelength scanning range of the OLT is reduced, the manufacturing difficulty and the cost of the OLT device sending the test light are reduced, and the optical splitter is easy to realize.

According to the first aspect, in a first possible implementation manner, in the N light-emitting sections, there is one light-emitting section where the optical filter structure is not disposed, and there is at least one light-emitting section where the optical filter structure is disposed.

According to the first aspect and the first possible implementation manner, in a second possible implementation manner, in the N light outgoing sections, at least one of the light outgoing sections is provided with M light filtering structures, each of the light outgoing sections filters optical signals with M wavelengths, and M is an integer greater than or equal to 2.

According to the first aspect and the first possible implementation manner, in a third possible implementation manner, at most one optical filter structure is disposed on each light exit segment.

Each light-emitting section is distinguished through the number of the light filtering structures, the filtering wavelength and the corresponding transmissivity, and the types of the test light are further reduced and the interval of the transmissivity is enlarged in multiple combination modes.

According to the first aspect and any one of the foregoing possible implementation manners, in a fourth possible implementation manner, the optical splitter is an equal-ratio optical splitter or an unequal-ratio optical splitter.

When the light-emitting section is an unequal ratio light splitter, the N light-emitting sections of the unequal ratio light splitter include 1 unequal ratio light-emitting section and N-1 equal ratio light-emitting sections, and the unequal ratio light-emitting section may not be provided with an optical filter structure.

Or one or at least two optical filtering structures can be arranged on the unequal light-emitting section. The unequal ratio light-emitting section and any one equal ratio light-emitting section meet the following conditions: said optical filtering structure capable of filtering the same wavelength is absent. By distinguishing the wavelength filtered by the unequal ratio light-out section from the wavelength filtered by the equal ratio light-out section, the wavelength filtered by the unequal ratio light-out section cannot influence the wavelength filtered by the equal ratio light-out section, and further, more levels of optical splitters can be arranged in the ODN, so that the optical link where the ONU is located can be identified.

When the optical splitter is an equal-ratio optical splitter, the optical splitter can be a planar optical waveguide PLC optical splitter, and the PLC optical splitter comprises an optical fiber at an optical input end, N optical fibers at an optical output end and a planar optical waveguide; the planar optical waveguide comprises an optical input waveguide end, N optical output waveguide ends and a middle branch waveguide connected between the optical input waveguide end and the N optical output waveguide ends; the light inlet end optical fiber is connected with the light inlet waveguide end, and the light inlet section comprises the light inlet end optical fiber and the light inlet waveguide end; the N light-emitting end optical fibers are connected with the N light-emitting waveguide ends in a one-to-one correspondence manner; each light-emitting section comprises the middle branch waveguide, a pair of light-emitting waveguide ends and a light-emitting end optical fiber which are connected with each other. The optical filter structure is disposed at least one of the intermediate branch waveguide, the light exit waveguide end, and the light exit end optical fiber.

The light-emitting end optical fiber comprises a strip fiber, the optical filtering structure is arranged on the strip fiber, the optical filtering structure is convenient to manufacture, the manufacturing is simple, for example, gratings can be etched in a centralized mode, and the cost is reduced.

The optical splitter further comprises a fixed box body, and the fixed box body is used for packaging and fixing the part, provided with the optical filtering structure, of the strip fiber inside the fixed box body. The fixed box body can straighten and fix the part of the optical grating on the strip fiber as much as possible and is arranged in a suspending way, so that the influence of the optical grating on external environmental factors, such as the influence of stress generated by artificial pulling, wind blowing and the like on the optical grating period, is reduced as much as possible, and the effect of protecting the optical grating is achieved

The optical splitter can also be a fused biconical taper optical splitter, the fused biconical taper optical splitter comprises an optical input end fiber, a coupling area fiber and N optical output end fibers, and the optical filtering structure is arranged on the optical output end fibers.

According to the first aspect and any one of the possible implementation manners, in another possible implementation manner, the optical filtering structure is a section of grating, or the optical filtering structure is a filter film.

In a second aspect, an optical distribution network, ODN, is provided, the ODN comprising a primary optical splitter and a secondary optical splitter; the first-stage optical splitter is the optical splitter of any one of the first aspect, an optical input section of the first-stage optical splitter is referred to as a first optical input section, and an optical output section of the first-stage optical splitter is referred to as a first optical output section; the second-stage optical splitter is the optical splitter of any one of the first aspect, an optical entrance section of the second-stage optical splitter is called a second optical entrance section, and an optical exit section of the second-stage optical splitter is called a second optical exit section; the first light-emitting section is connected with the second light-emitting section; the first light-in section, the first light-out section and the second light-in section which are connected with each other, and the second light-out section form an optical link; any two of the optical links satisfy at least one of the following conditions 1 and 2: condition 1, at least one of the wavelengths filtered is different; in condition 2, the transmittance of the optical signal for at least one of the wavelengths is different. Wherein there are at least two optical links that satisfy condition 2. Because the wavelength of the filtered optical signal between the two light-out sections can be different, or the transmissivity to the same optical signal is different, the light-out sections can be distinguished through the wavelength of the filtered optical signal, and can also be distinguished by combining the transmissivity to the same optical signal, so when the OLT side sends and tests the optical link where the optical detection ONU is located, the types of the test light can be reduced to a great extent, the wavelength resource is saved, the test light wavelength scanning range of the OLT is reduced, the manufacturing difficulty and the cost of the OLT device sending the test light are reduced, and the realization is easy.

According to a second aspect, in a first possible implementation manner of the ODN, the first optical splitter and the second optical splitter are equal ratio optical splitters, the number of the second optical splitters is multiple, each of the second optical splitters is the same optical splitter, and any one of the first optical splitters and any one of the second optical splitters are different optical splitters. The second-level optical splitter is the same optical splitter, so that the types of the optical splitters in the ODN can be greatly reduced, the production cost of a manufacturer is reduced, the installation by construction personnel is facilitated, and errors are not easy to occur in the installation process.

According to the second aspect and the first possible implementation manner, in a second possible implementation manner of the ODN, any one of the first light exiting sections and any one of the second light exiting sections satisfy: said optical filtering structure capable of filtering the same wavelength is absent. Therefore, for any optical link, only one optical filter structure exists for optical signals with the same wavelength to filter with a specific transmittance, optical splitters of different levels do not overlap the filtering of the optical signals with the same wavelength, and the optical splitters of different levels do not affect each other when filtering the optical signals.

According to the second aspect and any one of the foregoing possible implementation manners, in a third possible implementation manner of the ODN, the first-stage optical splitter and the second-stage optical splitter are both unequal-ratio optical splitters; the light-emitting section of the unequal ratio light splitter comprises 1 unequal ratio light-emitting section and N-1 equal ratio light-emitting sections; the unequal light-emitting section of the first-level light splitter is connected with the light-entering section of the second-level light splitter. The first-stage light splitter and the second-stage light splitter are the same unequal ratio light splitters. Therefore, the ODN only comprises one type of unequal-ratio optical splitters, the fewer types of optical splitters in the ODN are more beneficial to reducing the cost, and errors are not easy to generate in the installation process.

In a third aspect, a method for identifying an optical link in which an optical network unit ONU is located in a passive optical network PON system is provided, including: the OLT sends test light with Q wavelengths downstream, wherein Q is an integer greater than or equal to 1, and a first optical link between the OLT and a first ONU has specific transmissivity to the test light with at least one wavelength; the OLT receives feedback information fed back by the first ONU, wherein the feedback information is used for indicating the receiving power value of the test light; the OLT determines the transmissivity according to the receiving power value of the test light with at least one wavelength; and the OLT determines that the first ONU is positioned in the first optical link according to the relation between the optical link and the wavelength and the transmissivity, and the at least one wavelength and the determined transmissivity. Because the first optical link between the OLT and the first ONU transmits optical signals, the wavelength and the transmissivity are combined, when the OLT side transmits test light to detect the optical link where the ONU is located, the types of the test light can be reduced to a great extent, the wavelength resource is saved, the test light wavelength scanning range of the OLT is reduced, the manufacturing difficulty and the cost of a device of the OLT which transmits the test light are reduced, and the realization is easy.

According to the third aspect, in a first implementation manner of the third aspect, Q is greater than or equal to 2, and the OLT sending test lights of Q wavelengths downstream includes: the OLT sequentially sends the test lights with the Q wavelengths downwards according to a time sequence; after the OLT sends the test light with one wavelength downstream each time, waiting for receiving the feedback information fed back by the first ONU; and after receiving the feedback information, the OLT sends the test light with the next wavelength in a downlink. The mode does not need to occupy extra information to indicate the wavelength, and the wavelength can be judged directly according to the time sequence. No additional changes to the information format are required.

According to the third aspect, in a second implementation manner of the third aspect, each of the Q types of test lights with wavelengths sent downstream by the OLT carries a label, where the labels carried by any two types of test lights with wavelengths are different; the feedback information is used for indicating the receiving power value of the test light and the label carried in the test light; the method further comprises the following steps: and the OLT determines the wavelength of the test light corresponding to the receiving power value according to the label. In the mode, the OLT sends the test light and the ONU sends the feedback information without being limited by the time sequence, so that the method is flexible to realize.

According to the third aspect and any one of the foregoing implementation manners, in a third implementation manner of the third aspect, the method further includes: the OLT determines a maximum value of the received multiple receiving power values as a reference receiving power value; the OLT determining the transmittance according to the reception power value of the test light of at least one wavelength includes: and the OLT determines the transmissivity of the test light with at least one wavelength in the first optical link according to the receiving power value of the test light with at least one wavelength and the reference receiving power value. Alternatively, the method further comprises: the OLT sends a service optical signal downstream; the OLT receives service optical information fed back by the first ONU, wherein the service optical information is used for indicating a service optical receiving power value of the service optical signal; and the OLT determines the transmissivity of the test light with at least one wavelength in the first optical link according to the receiving power value of the test light with at least one wavelength and the receiving power value of the service light.

According to the third aspect and any one of the foregoing implementation manners, in a fourth implementation manner of the third aspect, the method further includes: the OLT transmits optical link information, wherein the optical link information is used for indicating the first optical link. The optical link information includes identification information of each optical splitter in each optical splitter, and identification information of each port located on the first optical link.

According to the third aspect and any one of the foregoing implementation manners, in a fifth implementation manner of the third aspect, the PON system includes an optical distribution network ODN, where the ODN is the ODN as described above.

In a fourth aspect, a method for identifying an optical link in which an optical network unit ONU is located in a passive optical network PON system is provided, including: an Optical Network Unit (ONU) receives test light with Q wavelengths sent by a light line terminal (OLT), wherein Q is an integer greater than or equal to 1, and a first optical link between the OLT and the ONU has specific transmissivity on the test light with at least one wavelength; the ONU determines a reception power value of the test light for each wavelength received; and the ONU sends feedback information to the OLT, wherein the feedback information is used for indicating the receiving power value of the test light. Because the first optical link between the OLT and the ONU transmits optical signals, the wavelength and the transmissivity are combined, when the OLT side transmits test light to detect the optical link where the ONU is located, the types of the test light can be reduced to a great extent, the wavelength resource is saved, the test light wavelength scanning range of the OLT is reduced, the manufacturing difficulty and the cost of a device of the OLT which transmits the test light are reduced, and the method is easy to realize.

According to a fourth aspect, in a first implementation manner of the third aspect, Q is greater than or equal to 2, and the receiving, by the ONU, the test light of Q wavelengths sent by the OLT includes: the ONU sequentially receives the test lights with the Q wavelengths sent by the OLT according to a time sequence; after receiving the test light of one wavelength, the ONU sends feedback information to the OLT, where the feedback information is used to indicate a reception power value of the test light of the one wavelength; and after transmitting the feedback information, the ONU receives the test light of the next wavelength. The mode does not need to occupy extra information to indicate the wavelength, and the wavelength can be judged directly according to the time sequence. No additional changes to the information format are required.

According to a fourth aspect, in a second implementation manner of the fourth aspect, each of the Q types of wavelength test lights received by the ONU carries a label, where the labels carried by any two types of wavelength test lights are different; the ONU transmitting the determined reception power value of the test light of each wavelength to the OLT includes: and the ONU sends feedback information to the OLT, wherein the feedback information is used for indicating the receiving power value of the test light and indicating the label carried in the test light. In the mode, the OLT sends the test light and the ONU sends the feedback information without being limited by the time sequence, so that the method is flexible to realize.

According to the fourth aspect and any one of the above implementation manners, in a third implementation manner of the fourth aspect, the method further includes: the ONU receives a service optical signal sent by the OLT; the ONU determines a service optical receiving power value of the service optical signal; and the ONU sends service optical information to the OLT, wherein the service optical information is used for indicating the service optical receiving power value of the service optical signal.

According to the fourth aspect and any one of the foregoing implementation manners, in a fourth implementation manner of the fourth aspect, the PON system includes an optical distribution network ODN, where the ODN is the above ODN.

In a fifth aspect, an OLT is provided, which includes a transceiver and a processor; the transceiver is configured to send test light with Q wavelengths downstream, where Q is an integer greater than or equal to 1, and a first optical link between the OLT and a first ONU has a specific transmittance for the test light with at least one wavelength; the transceiver is further configured to receive feedback information fed back by the first ONU, where the feedback information is used to indicate a reception power value of the test light; the processor is used for determining the transmissivity according to the receiving power value of the test light with at least one wavelength; the processor is further configured to determine that the first ONU is located on the first optical link according to the relationship between the optical link and the wavelength, the transmittance, and the at least one wavelength and the determined transmittance. Because the first optical link between the OLT and the first ONU transmits optical signals, the wavelength and the transmissivity are combined, when the OLT side transmits test light to detect the optical link where the ONU is located, the types of the test light can be reduced to a great extent, the wavelength resource is saved, the test light wavelength scanning range of the OLT is reduced, the manufacturing difficulty and the cost of a device of the OLT which transmits the test light are reduced, and the realization is easy.

According to a fifth aspect, in a first implementation manner of the fifth aspect, Q is greater than or equal to 2, and the transceiver sequentially sends down the test lights with the Q wavelengths in a time sequence; after the transceiver sends the test light with one wavelength in a downlink manner each time, waiting for receiving the feedback information fed back by the first ONU; and after receiving the feedback information, the transceiver sends the test light with the next wavelength in a downlink manner. The mode does not need to occupy extra information to indicate the wavelength, and the wavelength can be judged directly according to the time sequence. No additional changes to the information format are required.

According to the fifth aspect and the first implementation manner of the fifth aspect, in a second implementation manner of the fifth aspect, the transceiver is further configured to send optical link information, where the optical link information is used to indicate the first optical link, and the optical link information includes identification information of each optical splitter in each optical splitter and identification information of each port located on the first optical link.

In a sixth aspect, an ONU is provided, comprising a transceiver and a processor; the transceiver is used for receiving test light with Q wavelengths sent by an Optical Line Terminal (OLT), wherein Q is an integer greater than or equal to 1, and a first optical link between the OLT and the ONU has a specific transmissivity to the test light with at least one wavelength; the processor is used for determining the received power value of the test light of each wavelength received; the transceiver is further configured to send feedback information to the OLT, where the feedback information is used to indicate a reception power value of the test light. Because the first optical link between the OLT and the ONU transmits optical signals, the wavelength and the transmissivity are combined, when the OLT side transmits test light to detect the optical link where the ONU is located, the types of the test light can be reduced to a great extent, the wavelength resource is saved, the test light wavelength scanning range of the OLT is reduced, the manufacturing difficulty and the cost of a device of the OLT which transmits the test light are reduced, and the method is easy to realize.

According to the sixth aspect, in a first implementation manner of the sixth aspect, Q is greater than or equal to 2, and the transceiver sequentially receives the test lights with Q wavelengths sent by the OLT according to a time sequence; wherein, after receiving the test light of one wavelength, the transceiver sends feedback information to the OLT, the feedback information being used to indicate a reception power value of the test light of the one wavelength; and after transmitting the feedback information, the transceiver receives the test light of a next wavelength. The mode does not need to occupy extra information to indicate the wavelength, and the wavelength can be judged directly according to the time sequence. No additional changes to the information format are required.

According to the sixth aspect and the first implementation manner of the sixth aspect, in a second implementation manner of the sixth aspect, the transceiver is further configured to receive a service optical signal sent by the OLT; the processor is further configured to determine a service optical reception power value of the service optical signal; the transceiver is further configured to send service optical information to the OLT, where the service optical information is used to indicate a service optical receiving power value of the service optical signal.

In a seventh aspect, a passive optical network PON system is provided, where the PON system includes the optical line terminal OLT, the optical network unit ONU, and the optical distribution network ODN.

In a further aspect of the present application, a computer-readable storage medium is provided, in which corresponding computer software instructions for the OLT according to the third aspect and any of its implementations are stored, which, when run on a computer, cause the computer to perform the corresponding method steps according to the above aspects.

In a further aspect of the present application, a computer-readable storage medium is provided, in which corresponding computer software instructions for an ONU according to the fourth aspect and any implementation thereof are stored, which, when run on a computer, cause the computer to perform the corresponding method steps according to the above aspects.

Drawings

Fig. 1(1) is a schematic structural diagram of a PLC optical splitter according to an embodiment of the present invention;

fig. 1(2) is a schematic structural diagram of a PLC optical splitter according to another embodiment of the present invention;

fig. 1(3) is a schematic structural diagram of a PLC optical splitter in another embodiment of the present invention;

fig. 1(4) is a schematic structural diagram of a PLC optical splitter according to still another embodiment of the present invention;

FIG. 2 is a schematic view of the fixing box and the tape fiber according to an embodiment of the present invention;

fig. 3(1) is a schematic structural diagram of an FBT splitter according to an embodiment of the present invention;

fig. 3(2) is a schematic structural diagram of an FBT splitter according to another embodiment of the present invention;

FIG. 4 is a diagram of an optical filter structure for filtering an optical signal of a wavelength with a specific transmittance according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of an anisometric optical splitter according to an embodiment of the present invention;

FIG. 6 is an exemplary diagram of one implementation of an ODN;

fig. 7 is a schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

FIG. 8 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 9 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 10 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 11 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 12 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 13 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 14 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 15 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 16 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 17 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 18 is another schematic diagram of an ODN in a PON system according to an embodiment of the present invention;

fig. 19 is a flowchart illustrating a method for identifying an optical link where an ONU is located in a PON system according to an embodiment of the present invention;

fig. 20 is a schematic structural diagram of an OLT according to an embodiment of the present invention;

fig. 21 is a schematic structural diagram of an ONU in an embodiment of the present invention.

Detailed Description

The terms "first," "second," and the like in the description and in the claims of the present application and in the above-described drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are capable of operation in other sequences than described or illustrated herein. Furthermore, the terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a list of articles or devices is not necessarily limited to those structures explicitly listed, but may include other structures not expressly listed or inherent to such articles or devices, such that the inclusion of a structure in this application is merely illustrative of one type of structure and alternate structures may be implemented in practice, such that multiple components may be combined or integrated into another structure, or such that certain features of a structure may be omitted, or not implemented, and such that some or all of the structures shown or discussed as coupled to each other may be selected for purposes of illustration of embodiments of the present invention, according to actual requirements.

The technical solutions of the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention.

Embodiments of the present application provide an optical splitter, which may also be referred to as an optical splitter module, an optical splitter, and the like. The optical splitter is used for splitting one path of optical signals into multiple paths of optical signals. The optical splitter can be used in a scene requiring light splitting, for example, in an Optical Distribution Network (ODN). Taking the example of the optical splitter being used in an ODN, the optical splitter may be provided in an optical splitter, and the optical splitter may be, for example, an ODF, SSC, FDT, FAT, CBT (connected block terminal), ATB, or other devices in the ODN.

In an embodiment, referring to fig. 1(1), fig. 1(2), fig. 1(3), fig. 1(4), fig. 3(1), and fig. 3(2), fig. 1(1) to fig. 1(4) are schematic structural diagrams of the plane optical waveguide splitter in an embodiment of the present invention, and fig. 3(1) and fig. 3(2) are schematic structural diagrams of the fused biconical taper splitter in an embodiment of the present invention. The optical splitter includes an input optical section 100 and N output optical sections 200, where N is an integer greater than or equal to 2, and an optical signal enters through the input optical section 100 and is output from the N output optical sections 200. Each light-exiting section 200 of the at least N-1 light-exiting sections 200 is provided with at least one optical filtering structure 210, and each optical filtering structure filters an optical signal with one wavelength at a specific transmittance, which can also be understood as that the optical filtering structure 210 filters an optical signal with one central wavelength at a specific transmittance. It will be appreciated that the optical filter structure 210 filters a range of wavelengths of the optical signal having a center wavelength at which the transmission reaches a minimum. As shown in fig. 4, fig. 4 is a schematic diagram of the optical filter structure 210 filtering an optical signal of one wavelength with a specific transmittance, where the abscissa represents the wavelength and the ordinate represents the transmittance. Assuming that the transmittance reaches a minimum value of 20% at the center wavelength 1 in fig. 4, it can be understood that the optical filter structure 210 filters the optical signal of the wavelength 1 (or the center wavelength 1) with a specific transmittance.

The optical filter structure 210 filters an optical signal with a specific transmittance at a wavelength, wherein the specific transmittance may have a minimum value of 0 and a maximum value of less than 100%.

Wherein, any two light-exiting sections 200 provided with the light filtering structure 210 at least satisfy at least one of the following conditions 1 and 2: condition 1, at least one wavelength of the filtering is different; in condition 2, the transmittance for an optical signal of at least one wavelength is different. It is understood that only the condition 1 may be satisfied between any two light-exiting sections 200 provided with the light filtering structure 210, or only the condition 2 may be satisfied, or both the condition 1 and the condition 2 may be satisfied.

In an embodiment, at least two light-exiting sections 200 in the light-exiting section 200 provided with the light filtering structure 210 satisfy the condition 2. The condition 2 can be understood as that the transmittance for optical signals of the same wavelength is different. For example, if there is one light exit section 200 having a transmittance of 30% for an optical signal having a wavelength of 1 and there is one light exit section 200 having a transmittance of 70% for an optical signal having a wavelength of 1, it is considered that the two light exit sections 200 satisfy the condition 2.

In one embodiment, the optical input section 100 is an optical path in the optical splitter for transmitting the optical signal. The optical splitter divides one optical signal into N optical signals, and the light-out section 200 is a light path after the light-in section 100.

In an embodiment, the number of the light entrance sections 100 of the optical splitter may be 1, or may be at least 2. Taking 2 optical input segments 100 as an example, when the optical splitter is used in an ODN network, one optical input segment 100 is connected to a main optical fiber, and the other optical input segment 100 is connected to a spare optical fiber.

In an embodiment, as shown in fig. 1(1) to fig. 1(4), the optical splitter is a planar light wave circuit (PLC) optical splitter, and the PLC optical splitter includes an optical input end fiber 110, N optical output end fibers 221, and a planar optical waveguide 230. The PLC optical splitter may further include a substrate 240, and the planar optical waveguide 230 is disposed on the substrate 240. The planar optical waveguide 230 includes an input optical waveguide end 120, N output optical waveguide ends 231, and an intermediate branch waveguide 232 connected between the input optical waveguide end and the N output optical waveguide ends 231. The optical fiber 110 at the light input end is connected to the light input waveguide end. The N light-exiting-end optical fibers 221 are connected to the N light-exiting waveguide ends 231 in a one-to-one correspondence. The PLC splitter may further include an adhesive 250 for connecting the optical input end fiber 110 with the optical input waveguide end and connecting the optical output end fiber 221 with the optical output waveguide end 231. The light input section 100 includes a light input end fiber 110 and a light input waveguide end. Each light exit segment 200 includes an intermediate branch waveguide 232, a pair of interconnected light exit waveguide ends 231, and a light exit end fiber 221. It will be appreciated that each light-exiting section 200 comprises a portion of the intermediate branch waveguide 232, for example, the intermediate branch waveguide 232 in the first light-exiting section 200 shown in fig. 1(1) comprises M21, M31; the intermediate branch waveguide 232 in the second light-exiting section 200 includes M21, M32. In one embodiment, the ends of the N light-exiting-end optical fibers 221 form the optical fiber array 220, the substrate 240 and the waveguides form an optical splitter chip, the optical splitter chip and the optical fiber array 220 are bonded together by the adhesive 250, and the N light-exiting waveguide ends 231 are connected to the N light-exiting-end optical fibers 221 in a one-to-one correspondence.

In another embodiment, as shown in fig. 3(1) and fig. 3(2), the optical splitter is a Fused Biconical Taper (FBT) optical splitter, and the FBT optical splitter includes an optical input end fiber 110, a coupling region fiber 270, and N optical output end fibers 221. The FBT optical splitter bundles two or more optical fibers together, then performs fusion drawing on a tapering machine, and monitors the change of the splitting ratio in real time, the fusion drawing is completed after the splitting ratio meets the requirement, wherein one optical fiber is reserved at the input end, the other optical fibers are cut off, the reserved optical fiber is used as the optical fiber 110 at the light input end, and each optical fiber at the output end is used as the N optical fibers 221 at the light output end. The light-input section 100 may include the light-input end fiber 110, and the light-output section 200 may include the N light-output end fibers 221.

In one embodiment, one optical filtering structure 210 is a segment of a grating that filters one wavelength of optical signal at a particular transmittance.

The grating is a diffraction grating formed by periodically modulating the refractive index of the light exit section 200 in the axial direction by a certain method. The grating may be a fiber grating (i.e., the grating is formed on the fiber) or a waveguide grating (i.e., the grating is formed on the waveguide). The fiber grating may be a Fiber Bragg Grating (FBG) or a long period grating (LPFG).

Taking fiber grating as an example, generally, the photosensitivity of the fiber material is utilized, and the incident light coherent field pattern is written into the fiber core by the ultraviolet light exposure method, so as to generate the periodic variation of the refractive index along the axial direction of the fiber core in the fiber core, thereby forming the phase grating of the permanent space. In addition, the fiber grating can also be manufactured by a femtosecond laser, a carbon dioxide laser and the like. The preparation method of the fiber grating can also be adopted for the grating on the waveguide.

A segment of the grating can be viewed as a band-stop filter for a particular center wavelength. When one beam of optical signal with a broad spectrum passes through the grating, the optical signal with a specific central wavelength is totally reflected, and the optical signals with the other wavelengths are transmitted continuously through the grating; alternatively, the grating filters the optical signal with a certain transmittance, i.e. the optical signal with a certain center wavelength is partially reflected, and the optical signal with a certain center wavelength is partially transmitted through the grating, and the optical signals with the rest wavelengths are transmitted through the grating.

It will be appreciated that the grating filters a range of wavelengths of the optical signal having the center wavelength.

The central wavelength and the transmissivity can be controlled by adjusting the grating period, the grating pitch and the exposure time in the grating manufacturing process.

In another embodiment, the light filter structure 210 may also be a filter film. The filter may be a thin film plated on the waveguide or optical fiber. For example, the end face of the waveguide may be coated, or the waveguide may be open and then coated, or the end face of the optical fiber may be coated, or the optical fiber may be open and then coated. The number, the position, and other arrangement manners of the filter films on each light-emitting section 200 can refer to the corresponding descriptions of the gratings, and are not described herein again. It will be appreciated that the filter filters a range of wavelengths of light signals having the center wavelength.

The number of optical filter structures 210 disposed on each light-exiting segment 200 may have various embodiments:

in an embodiment, at most one optical filter structure 210 is disposed on each light-emitting section 200, and the fewer the number of the optical filter structures 210 is, the simpler the production process of the optical splitter is, the smaller the manufacturing difficulty is, and the cost is reduced. Two situations are included: in a case, each of the N light-exiting sections 200 is provided with 1 optical filtering structure 210, and each light-exiting section 200 filters an optical signal with one wavelength, that is, the optical filtering structure 210 on each light-exiting section 200 filters an optical signal with one wavelength. In case two, there is one light-exiting section 200 without the light-filtering structure 210 in the N light-exiting sections 200, and each of the remaining N-1 light-exiting sections 200 has 1 light-filtering structure 210.

In another embodiment, at least one light-exiting section 200 is provided with M optical filtering structures 210, each light-exiting section 200 filters optical signals with M wavelengths, where M is an integer greater than or equal to 2. For example, N-8, each light-exiting section 200 is provided with 2 optical filter structures 210, or a part of the light-exiting sections 200 is provided with 1 optical filter structure 210, and the rest of the light-exiting sections 200 are provided with 2 optical filter structures 210.

In another embodiment, there is one light-exiting section 200 without the optical filtering structure 210 among the N light-exiting sections 200. The remaining light exiting sections 200 are provided with at least 1 light filtering structure 210. Further, case one: of the N light exit segments 200, there is also at least one light exit segment 200 provided with one light filtering structure 210, for example, N-8, where 1 light exit segment 200 is not provided with a light filtering structure 210, and the remaining 7 light exit segments 200 are each provided with 1 light filtering structure 210 or each provided with 2 light filtering structures 210. Case two: in the N light-exiting sections 200, there is at least one light-exiting section 200 provided with one of the light-filtering structures 210, and there is at least one light-exiting section 200 provided with at least two of the light-filtering structures 210, for example, N ═ 8, where 1 light-exiting section 200 is not provided with a light-

filtering structure

210, 2 light-exiting sections 200 are provided with 1 light-filtering structure 210, and the remaining 5 light-exiting sections 200 are provided with at least 2 light-filtering structures 210. Case three: in the N light-exiting sections 200, there is also at least one light-exiting section 200 in which at least two light-filtering structures 210 are disposed, for example, N-8, where 1 light-exiting section 200 is not provided with a light-filtering structure 210, and the remaining 7 light-exiting sections 200 are each provided with at least two light-filtering structures 210.

In one embodiment, for a PLC optical splitter, the optical filtering structure 210 is disposed at least one of the intermediate branch waveguide 232, the light-exiting waveguide end 231 (shown in fig. 1 (2)), and the light-exiting end fiber 221 (shown in fig. 1(1), fig. 1(3), and fig. 1 (4)).

In one embodiment, as shown in fig. 1(3) and fig. 1(4), the light-exiting end optical fiber 221 includes an optical fiber 222, a ribbon fiber 223, a pigtail 224, and the like on the optical fiber array 220. As shown in fig. 1(4), the optical splitter further includes a splitter 225, one end of the splitter 225 is connected with the optical fiber 223, the other end is connected with the pigtail 224, and the optical fiber 223 is located between the splitter 225 and the optical fiber 222 on the optical fiber array 220. The optical filter structure 210 disposed on the light-exiting end optical fiber 221 includes: the optical filtering structure 210 is disposed on at least one of an optical fiber 222 (fig. 1(1)), a ribbon fiber 223 (fig. 1(3)), and a pigtail on the optical fiber array 220.

In one embodiment, as shown in fig. 1(2), all of the M optical filtering structures 210 on one light-exiting section 200 are disposed on the light-exiting waveguide end 231; or may be provided entirely on the light-exiting-end optical fiber 221. As shown in fig. 1(1), all of the M optical filtering structures 210 on one light-exiting section 200 are disposed on the optical fibers 222 on the optical fiber array 220; or as shown in fig. 1(3), all of the M optical filtering structures 210 on one light-exiting section 200 are disposed on the fiber 223; alternatively, as shown in fig. 1(4)), all of the M optical filtering structures 210 on one light-exiting section 200 are disposed on the pigtail 224. Alternatively, the M optical filter structures 210 on one light-exiting section 200 may be dispersedly disposed on at least two of the light-exiting waveguide end 231, the light-exiting end optical fiber 221 (including the optical fiber 222, the ribbon fiber 223, and the pigtail 224 on the optical fiber array 220), and the intermediate branch waveguide 232.

In one embodiment, for an FBT splitter, the optical filtering structure 210 is disposed on the light-exiting end fiber 221.

In an embodiment, for example, all the optical filtering structures 210 are gratings, and the gratings are all disposed on the fiber 223, as shown in fig. 1(3) and fig. 2, the optical splitter further includes a fixing box 260 for fixing the portion of the fiber 223 on which the gratings are disposed inside the fixing box 260. The fixed box 260 can straighten and fix the part of the optical grating on the belt fiber 223 as much as possible, and is arranged in a suspended mode, so that the influence of external environment factors, such as the influence of stress generated by artificial pulling, wind blowing and the like, on the optical grating period is reduced as much as possible, and the effect of protecting the optical grating is achieved. As shown in fig. 2, which is a schematic view of fixing the fixing box 260 and the strip fiber 223, the sleeve of the strip fiber 223 is stripped at the middle part of the strip fiber 223, the optical fiber is exposed, the grating is carved on the exposed optical fiber, and the strip fiber 223 is fixed at two opposite ends of the fixing box 260, so that the optical fiber exposed in the middle of the strip fiber 223 is straightened and fixed. The fixing box 260 may be fixed with the optical fiber 223 by fixing glue, or may be fixed by clamping or the like.

It is understood that, when the optical filter structure 210 is a filter film, the modes shown in fig. 1(1) to fig. 1(4) may also be adopted, and the above-mentioned advantages may also be achieved, which are not described herein again.

It should be understood that the optical fiber 110 at the light input end refers to the optical fiber at the end with less branches of the optical splitter. The light exit end optical fiber 221 is an optical fiber at each end where the optical splitter has many branches. The optical signal may enter from the optical fiber 110 at the light input end, be divided into multiple optical signals by the optical splitter, and be output through the optical fibers 221 at the light output end. The optical signal may enter from the optical fiber 221 at the light exit end and be output through the optical fiber 110 at the light entrance end.

In one embodiment, the optical splitter is an equal ratio optical splitter. The power of the optical signals output by the N optical output sections 200 of the equal-ratio optical splitter is the same or substantially the same. As shown in fig. 1(1) to 1(4), the equal ratio splitter may be a PLC splitter. As shown in fig. 3(1) and 3(2), the equal ratio optical splitter may be an FBT optical splitter.

In another embodiment, as shown in FIG. 5, the beam splitter is an unequal ratio beam splitter. The N light-exiting sections 200 of the unequal ratio splitter include 1 unequal ratio light-exiting section 201 and N-1 equal ratio light-exiting sections 202. The power of the optical signal output by each equal-ratio light-exiting section 202 is the same or substantially the same. The unequal ratio light-exiting section 201 is also generally referred to as a large branching ratio light-exiting section 200, and the power of the optical signal output by the unequal ratio light-exiting section 201 is different from or greatly different from the power of the optical signal output by each equal ratio light-exiting section 202. In general, the power of the optical signal output by the unequal ratio light-emitting segment 201 is greater than the power of the optical signal output by each equal ratio light-emitting segment 202. Accordingly, the anisometric splitter includes 1 anisometric light-exiting end optical fiber 221 and N-1 anisometric light-exiting end optical fibers 221.

The unequal ratio optical splitter can be a PLC optical splitter or an FBT optical splitter.

Or the unequal ratio optical splitter can also be a PLC and FBT combined optical splitter. For example, the 1:2 optical splitting section in fig. 5 can be implemented by FBT, and the 1:8 optical splitting section can be implemented by PLC. Taking fig. 5 as an example, the output optical power ratio of the two branch ends of the 1:2 light splitting section is 30% to 70%, wherein 30% branch ends of the 1:2 light splitting section are connected with the 1:8 light splitting section.

In one embodiment, the unequal light-exiting section 201 is provided with one optical filtering structure 210, and the unequal light-exiting section 201 filters optical signals of one wavelength. At most one equal-ratio light-emitting section 202 without the optical filter structure 210 exists in each equal-ratio light-emitting section 202.

In one embodiment, the unequal light-exiting section 201 and any equal light-exiting section 202 satisfy the following conditions: there is no optical filtering structure 210 capable of filtering the same wavelength. For example, if the unequal light-exiting section 201 filters optical signals of wavelength 1 and the equal light-exiting section 202 filters optical signals of wavelength 1 and wavelength 2, it is considered that the optical filter structure 210 capable of filtering the same wavelength exists. When the unequal light-exiting section 201 filters the optical signal of the wavelength 1 and the equal light-exiting section 202 filters the optical signals of the

wavelengths

2 and 3, it is considered that the optical filter structure 210 capable of filtering the same wavelength does not exist between the two.

In another embodiment, the unequal light-exiting sections 201 are not provided with the optical filtering structures 210, and each equal light-exiting section 202 is provided with at least one optical filtering structure 210.

In another embodiment, the unequal ratio light exit segment 201 provides at least two light filtering structures 210. The unequal light-emitting section 201 and any equal light-emitting section 202 satisfy the following conditions: there is no optical filtering structure 210 capable of filtering the same wavelength. Taking the example of two optical filter structures 210, if the unequal light-exiting section 201 filters optical signals with

wavelengths

1 and 3, and the equal light-exiting section 202 filters optical signals with

wavelengths

1 and 2, it is considered that there are optical filter structures 210 capable of filtering the same wavelengths. When the unequal light-exiting section 201 filters the optical signals of the wavelength 1 and the wavelength 3, and the equal light-exiting section 202 filters the optical signals of the wavelength 2 and the wavelength 4, it is considered that the optical filter structure 210 capable of filtering the same wavelength is not present in both.

It is understood that if the number of wavelength types of the optical signals that can be filtered by the two light-exiting sections 200 is different, the two light-exiting sections 200 are considered to satisfy the above condition 1. For example, if one light-exiting section 200 is not provided with the optical filtering structure 210 (i.e. the number of the filtered wavelength types is 0), and the other light-exiting section 200 is provided with at least 1 optical filtering structure 210 (i.e. the number of the filtered wavelength types is at least 1), the above condition 1 can be considered to be satisfied. For another example, if one light-exiting section 200 has 1 optical filter structure 210 (i.e., the number of the filtered wavelength types is 1) and the other light-exiting section 200 has 2 optical filter structures 210 (i.e., the number of the filtered wavelength types is 2), it is considered that the above condition 1 is satisfied.

It can be understood that if the number of the light filtering structures 210 on the two light-exiting sections 200 is the same, and the wavelengths filtered on the two light-exiting sections 200 are not all the same, the two light-exiting sections 200 are considered to satisfy the above condition 1. For example, if the wavelengths filtered by one light-exiting section 200 are wavelength 1 and wavelength 2, and the wavelengths filtered by the other light-exiting section 200 are wavelength 1 and wavelength 3, it is considered that the above condition 1 is satisfied. For another example, if the wavelengths filtered by one light-exiting section 200 are wavelength 1 and wavelength 2, and the wavelengths filtered by the other light-exiting section 200 are wavelength 3 and wavelength 4, it is considered that the above condition 1 is satisfied.

It can be understood that if the optical signals with the wavelength of 1 can be filtered on both of the two light-exiting sections 200, wherein the transmittance of one light-exiting section 200 for the optical signals with the wavelength of 1 is R1, the transmittance of the other light-exiting section 200 for the optical signals with the wavelength of 1 is R2, and R1 is different from R2, the two light-exiting sections 200 are considered to satisfy the above condition 2.

In another embodiment, the unequal splitter may also include 2 or more than 2 unequal light-exiting sections 201.

The embodiment of the application also provides an ODN, which comprises a primary optical splitter and a secondary optical splitter.

The first-stage optical splitter and the second-stage optical splitter are the optical splitters described in the above embodiments.

The ODN may further include an ODF, SSC, FDT, FAT, ATB, etc., the primary optical splitter may be provided in the FDT, FAT, ODF, SSC, etc., and the secondary optical splitter may be provided in the FDT, FAT, ODF, SSC, etc. The first and second beam splitters may be provided in different types of devices or in the same device.

It is understood that the first-stage optical splitter and the second-stage optical splitter in the embodiments of the present application are relative concepts, and the light-in section 100 of the second-stage optical splitter is directly or indirectly connected to the light-out section 200 of the first-stage optical splitter. The ODN shown in fig. 7 includes four levels of optical splitters, namely, optical splitter 11, optical splitter 21, optical splitter 31, and optical splitter 41. The light-entering section 100 of the optical splitter 12 is directly connected to a light-exiting section 200 of the optical splitter 11 through an optical fiber, so that the optical splitter 11 may be referred to as a first-stage optical splitter, and the optical splitter 12 may be referred to as a second-stage optical splitter. In addition, the light-in section 100 of the optical splitter 31 is directly connected to a light-out section 200 of the optical splitter 21 through an optical fiber, so that the optical splitter 21 may also be referred to as a primary optical splitter, and the optical splitter 31 may be referred to as a secondary optical splitter. In addition, the light-in section 100 of the optical splitter 31 is indirectly connected to a light-out section 200 of the optical splitter 11 through the optical splitter 21, so that the optical splitter 11 can be referred to as a first-stage optical splitter, and the optical splitter 31 can be referred to as a second-stage optical splitter.

For convenience of description, the light-in section 100 of the first-order splitter is referred to as a first light-in section 100, and the light-out section 200 of the first-order splitter is referred to as a first light-out section 200; the light-in section 100 of the secondary beam splitter is referred to as a second light-in section 100, and the light-out section 200 of the secondary beam splitter is referred to as a second light-out section 200.

A first light-exiting section 200 is connected to a second light-entering section 100, and it is understood that the first light-exiting section may be directly connected or indirectly connected. The first optical input section 100, a pair of interconnected first and second

optical output sections

200 and 100, and a second optical output section 200 form an optical link.

In one implementation, as shown in fig. 6, the ODN includes 1 primary

optical splitter

11 and 8 secondary

optical splitters

21, 8 secondary optical splitters being identical, only 2 secondary optical splitters being shown in fig. 6, and the remaining secondary optical splitters not shown. The wavelengths filtered by any two first light-exiting sections 200 are different, and the wavelengths filtered by any one first light-exiting section 200 and any one second light-exiting section 200 are different. The optical link in the ODN of fig. 6 is therefore capable of filtering 16 wavelengths of optical signals. Therefore, in the process that the OLT sends the test optical signals to identify the optical link where each ONU is located, the OLT sends the test optical signals with 16 wavelengths. Not only occupies a lot of wavelength resources, but also causes the scanning wavelength range of the OLT side to be too large, and the cost is higher.

In the embodiment of the present invention, as shown in fig. 7 to 18, any two optical links satisfy at least one of the following conditions 1 and 2: condition 1: at least one of the wavelengths filtered is different; condition 2: the transmittance of the optical signal for at least one wavelength is different. The specific descriptions of

conditions

1 and 2 can refer to the description of the optical splitter, and are not repeated herein.

It is understood that if the number of wavelength types of the optical signals that can be filtered by the two optical links is different, the two optical links are considered to satisfy the above condition 1. For example, if the number of the wavelength types filtered by one optical link is 0 and the number of the wavelength types filtered by the other optical link is at least 1, it is considered that the above condition 1 is satisfied. For another example, if the number of the wavelength types filtered by one optical link is 1 and the number of the wavelength types filtered by the other optical link is 2, it is considered that the above condition 1 is satisfied.

It is understood that if the number of types of optical signals that can be filtered by the two optical links is the same, and the wavelengths filtered by the two optical links are not all the same, the two optical links are considered to satisfy the above condition 1. For example, if the wavelength filtered by one optical link is the wavelength 1 and the wavelength 2, and the wavelength filtered by the other optical link is the wavelength 1 and the wavelength 3, it is considered that the above condition 1 is satisfied. For another example, if the wavelength filtered by one optical link is the wavelength 1 and the wavelength 2, and the wavelength filtered by the other optical link is the wavelength 3 and the wavelength 4, it is considered that the above condition 1 is satisfied.

In an embodiment, there are at least two optical links that satisfy condition 2. For example, if there is one optical link whose transmittance for an optical signal of wavelength 1 is 30% and there is one optical link whose transmittance for an optical signal of wavelength 1 is 70%, the two optical links are considered to satisfy the condition 2.

In the invention, any two light splitting sections of the light splitter meet at least one of the condition 1 and the condition 2, any two optical links meet at least one of the condition 1 and the condition 2, at least two light outgoing sections meet the condition 2 exist in the light outgoing section provided with the optical filtering structure, and at least two optical links meet the condition 2. Therefore, by combining the two conditions of the wavelength and the transmissivity, the types of the test light can be reduced to a great extent, the wavelength resource is saved, the wavelength scanning range of the test light of the OLT is favorably reduced, the manufacturing difficulty and the cost of a device (such as an adjustable laser) of the OLT for sending the test light are greatly reduced, and the realization is easy.

In an embodiment, as shown in fig. 8 to 14, the first-stage optical splitter and the second-stage optical splitter are equal-ratio optical splitters, the second-stage optical splitters are multiple (only 2 second-stage optical splitters are shown in fig. 8 to 10, and the rest are not shown), each second-stage optical splitter is the same optical splitter, and any first-stage optical splitter and any second-stage optical splitter are different optical splitters. Therefore, even if each secondary optical splitter is the same optical splitter, since any two first optical outgoing sections 200 of the primary optical splitter at least satisfy one of the

above conditions

1 and 2, the first optical outgoing section 200 of the optical link where the ONU is located can still be identified, that is, the port of the primary optical splitter on the optical link where the ONU is located is identified; meanwhile, any two second light-exiting sections 200 of the secondary optical splitter at least meet the condition 1 and the condition 2, so that the second light-exiting section 200 of the optical link where the ONU is located can be further identified, that is, the port of the secondary optical splitter on the optical link where the ONU is located is identified. In this embodiment, the second grade spectroscope is the same spectroscope, can greatly reduce the kind of spectroscope in the ODN, firstly reduces manufacturer's manufacturing cost, secondly is convenient for constructor installation, is difficult to make mistakes in the installation.

Further, as shown in fig. 8 and 9, any one of the first light-exiting sections 200 and any one of the second light-exiting sections 200 satisfies: there is no optical filtering structure 210 capable of filtering the same wavelength. Therefore, for any optical link, only one optical filter structure 210 exists for filtering optical signals with the same wavelength by a specific transmittance, optical splitters of different levels do not overlap the filtering of optical signals with the same wavelength, and optical splitters of different levels do not affect each other when filtering optical signals.

Further, in an embodiment, as shown in fig. 9, the wavelengths filtered by any two first light-exiting sections 200 are the same, and the transmittances of any two first light-exiting sections 200 for the filtered wavelengths are different. The wavelengths filtered by any two second light-exiting sections 200 are the same, and the transmittances of any two second light-exiting sections 200 to the filtered wavelengths are different. I.e., the ports of the primary splitter are distinguished by transmissivity and the ports of the secondary splitter are distinguished by transmissivity, with the splitter levels being distinguished by the wavelength being filtered. The types of test lights can be further reduced, and wavelength resources are saved. In another embodiment, as shown in fig. 8, the levels of the optical splitters may be distinguished by wavelengths, and the ports of the optical splitters may be distinguished by combinations of wavelengths and transmittances, which not only reduces the types of test lights, but also makes the transmittance intervals of different ports for the same wavelength as large as possible, is more beneficial to identifying the optical link, and improves the accuracy of identifying the optical link.

In another embodiment, as shown in FIG. 10, the splitter levels may also be differentiated by transmissivity, and the splitter ports by wavelength.

In order to further reduce the test light types and simultaneously make the transmittance intervals of different ports for the same wavelength as large as possible, as described in the above embodiment of the optical splitter, at least M optical filter structures 210 may be disposed on at least one light-exiting section 200 of the first-stage optical splitter, and also at least M optical filter structures 210 may be disposed on at least one light-exiting section 200 of the second-stage optical splitter, where M is an integer greater than or equal to 2. In the following, for example, 2 optical filter structures 210 are disposed on each light-emitting section 200 of the first-order optical splitter and the second-order optical splitter, as shown in fig. 11, for example, the light-emitting section 2001 of the first-order optical splitter has a transmittance of 0% for a wavelength 1 and a transmittance of 0% for a wavelength 2; the transmittance of the light-emitting section 2006 for the wavelength 1 is 40%, and the transmittance for the wavelength 2 is 80%, the same principle can be used for the transmittance of the remaining light-emitting section 200 and the second-stage optical splitter for each wavelength, see fig. 11, which is not described herein again, the number of the wavelength types filtered by each stage of optical splitter is only 4, and the transmittance interval reaches 20% to 40%. As shown in fig. 12, the first and second optical splitters filter a total of 8 wavelength types, and the transmittance interval reaches 50%. As shown in fig. 13, the first and second optical splitters filter 6 kinds of wavelengths, and the transmittance interval is 50%. It can be seen that, by increasing the number of the optical filter structures 210 disposed on one light-emitting section 200, the transmittance intervals of different light-emitting sections 200 for the same wavelength can be enlarged as much as possible while the types of the test light are effectively reduced.

In an embodiment, in order to further reduce the types of test lights and simultaneously make the transmittance intervals of different ports to the same wavelength as large as possible, the number of the optical filtering structures 210 disposed on each light-emitting section 200 of the first-order splitter may be different, for example, there is one light-emitting section 200 without the optical filtering structure 210, and there are 1 light-emitting sections 200 with the optical filtering structures 210. As shown in fig. 14, there may be further 2 light-exiting sections 200 provided with optical filter structures 210. The light-emitting sections 200 are distinguished by the number of light filtering structures, the filtering wavelength and the corresponding transmittance, and the light-emitting sections are combined in various ways, so that the types of test light are further reduced, and the transmittance interval is expanded. The second-stage optical splitter is the same as the first-stage optical splitter, and is not described herein again. In the embodiment, the wavelength types filtered by the first-stage light splitter and the second-stage light splitter are only 4, and the transmissivity interval reaches 50%, so that the transmissivity interval is enlarged as much as possible while the testing light types are effectively reduced.

In one embodiment, as shown in fig. 7 and 15-18, both the primary and secondary splitters are unequal ratio splitters. In one example, the number of each stage of the optical splitters is one, and the light entrance section 100 of the next stage of the optical splitters is connected to the unequal ratio light exit section 201 of the previous stage of the optical splitters. It is understood that in other examples, there may be at least two splitters of the same level.

In one example, no optical filter structure 210 is disposed on the unequal ratio light exit segment 201 of each stage of the optical splitter. As shown in fig. 7, 3 anisometric splitters (such as

splitters

11,21,31 in fig. 7) and 1 anisometric splitter (such as splitter 41 in fig. 7) are included, each anisometric splitter stage distinguishing the splitter level by wavelength and the splitter port by transmittance. It is understood that in other embodiments, as shown in fig. 15, each stage of the unequal ratio splitter may also distinguish splitter stages by transmissivity, as well as splitter ports by wavelength. Or in other embodiments, as shown in fig. 16, each stage of the anisometric optical splitter may also distinguish between splitter stages by wavelength, and splitter ports by a combination of wavelength and transmittance.

In another example, an optical filter structure 210 is disposed on the unequal light-exiting section 201. The unequal ratio light-exiting sections 201 of the unequal ratio optical splitters of each stage may filter optical signals with the same wavelength or different wavelengths. Each stage of the unequal ratio optical splitter can distinguish the optical splitter stage by wavelength or transmissivity or a combination thereof, and can also distinguish the optical splitter ports by wavelength or transmissivity or a combination thereof. It is also possible that the unequal splitters of the respective levels are identical unequal splitters, as shown in fig. 17 and 18. As shown in fig. 17, each of the proportional light-emitting sections 202 of the first-order spectroscope 11 filters only the wavelength 1, each of the proportional light-emitting sections 202 of the second-order spectroscope 21 filters the wavelength 2 with a transmittance of 70%, and also filters the wavelength 1 at the same time, each of the proportional light-emitting sections 202 of the third-order spectroscope 31 filters the wavelength 2 with a transmittance of 70% to 49%, and also filters the wavelength 1 at the same time, and the fourth-order spectroscope is an proportional spectroscope and filters the wavelength 2 with a transmittance of 70% to 70% and 34%, and also filters the wavelength 1 at the same time. Each of the equal-ratio light-exiting sections 202 of the unequal-ratio optical splitters of each level and the equal-ratio optical splitter of the fourth level filters the optical signal of wavelength 1 and distinguishes the ports by the transmittance of wavelength 1. The order of the individual splitters is distinguished by the transmittance at wavelength 2. Therefore, the ODN only comprises two types of optical splitters, so that the production cost of a manufacturer is reduced, the ODN is convenient for constructors to install, and errors are not easy to occur in the installation process. As shown in fig. 18, each of the equal-ratio light-exiting sections 202 of the unequal-ratio optical splitters of each stage and the equal-ratio optical splitters of the fourth stage filter the optical signals of the wavelength 1 and the wavelength 2 and distinguish the ports by the transmittance of the wavelength 1 and the transmittance of the wavelength 2, and the stages of the unequal-ratio optical splitters of each stage are distinguished by the transmittance of the wavelength 3. The ODN only comprises two types of optical splitters, the fewer the types of the optical splitters in the ODN are, the more beneficial the cost reduction is, and errors are not easy to occur in the installation process.

In one embodiment, the unequal light-exiting section 201 and any equal light-exiting section 202 satisfy the following conditions: there is no optical filtering structure 210 capable of filtering the same wavelength. By distinguishing the wavelength filtered by the unequal ratio light-out section 201 from the wavelength filtered by the equal ratio light-out section 202, the wavelength filtered by the unequal ratio light-out section 201 does not influence the wavelength filtered by the equal ratio light-out section 202, and further, more levels of optical splitters can be arranged in the ODN, so that the optical link where the ONU is located can be identified.

It is understood that, for the specific implementation of the equal-ratio light-exiting section 202 of each stage of the unequal-ratio optical splitter, reference may be made to the above description of each stage of the equal-ratio optical splitter (for example, fig. 8 to 14), which also has the above-described effects, and further description is omitted here.

In other examples, at least two optical filtering structures 210 may be disposed on the unequal light-exiting section 201.

In one embodiment, as shown in FIG. 7, and FIGS. 15-18, the first splitter 31 is an unequal splitter and the second splitter 41 is an equal splitter. The detailed description may refer to the related description above, and will not be repeated herein.

It is understood that in the above embodiments, the first-stage optical splitter and the second-stage optical splitter may have the optical filtering structure 210 capable of filtering the same wavelength, as long as at least one of the

above conditions

1 and 2 is satisfied between the optical links.

The PON system in the present application may be a next-generation PON (NG-PON), NG-PON1, NG-PON2, gigabit-capable PON (GPON), 10gigabit per second PON (10gigabit per second PON, XG-PON), symmetric 10 gigabit-capable passive optical network (10-gigabit-capable passive optical network, XGs-PON), Ethernet PON (Ethernet PON, EPON), 10gigabit per second EPON (10gigabit per second EPON, 10G-PON), next-generation PON (NG-PON ), wavelength division multiplexing (wavelength-division multiplexing, WDM) PON, time-division multiplexing (WDM-wavelength-division multiplexing, WDM) PON, point-to-point (WDM-wavelength-division multiplexing, WDM-wavelength-division multiplexing (WDM-PON, WDM-wavelength-division multiplexing, WDM-PON), WDM-node (WDM-node) PON, WDM-node (P-node, WDM-node, or node (P-node), APON), Broadband PON (BPON), and the like, and 25gigabit per second PON (25gigabit per second PON, 25G-PON), 50gigabit per second PON (50gigabit per second PON, 50G-PON), 100gigabit per second PON (100gigabit per second PON, 100G-PON), 25gigabit per second n (25gigabit per second PON, 25G-EPON), 50gigabit per second EPON (50gigabit per second EPON, 50G-EPON), 100gigabit per second EPON (100gigabit per second EPON, 100G-EPON), and other various PON systems specified by ITU, or other various PON systems specified by IEEE, and the like.

The PON system may include an OLT, an ODN, and at least one ONU (shown in fig. 7-18). In this PON system, a direction from the OLT to the ONUs is defined as a downstream direction, and a direction from the ONUs to the OLT is defined as an upstream direction.

The OLT is a core component of an optical access network, usually located in a Central Office (CO), and may collectively manage at least one ONU, and the OLT is configured to provide data for each ONU accessing and management, and so on. The OLT may be configured to send optical signals to each ONU, receive information fed back by each ONU, and process the information or other data fed back by the ONU.

The ONU is configured to receive data transmitted from the OLT, respond to a management command of the OLT, buffer ethernet data of a user, and transmit the data in an upstream direction in a transmission window allocated by the OLT, and the like.

The ODN may be the ODN described in the above embodiments, and is not described herein again. It is understood that the following embodiments also have the advantageous effects described in the above-described ODN embodiments.

Taking fig. 14 as an example, the ODN includes a primary optical splitter 11, which includes 8 ports, and each port is connected to a secondary optical splitter, that is, there are 8 secondary optical splitters in total. Fig. 14 shows only two

secondary splitters

21 and 22, where the secondary splitter 21 is connected to port 1 of the primary splitter, the secondary splitter 22 is connected to port 6 of the primary splitter, the remaining secondary splitters are not shown, and the remaining secondary splitters may be the same splitters as the

secondary splitters

21 and 22. Each secondary optical splitter comprises 8 ports, each port can be connected to one ONU, wherein port 4 of the secondary optical splitter 21 is connected to the first ONU301, port 7 of the secondary optical splitter 22 is connected to the second ONU302, and the remaining ONUs are not shown. The ODN includes a total of 64 optical links. For convenience of description, hereinafter, an optical link between the OLT and the first ONU301 is referred to as a first optical link, and an optical link between the OLT and the second ONU302 is referred to as a second optical link.

It is to be understood that fig. 14 is an exemplary diagram, the optical links where the first ONU301 and the second ONU302 are located are not limited to the optical links shown in fig. 14, and the following description of the embodiments regarding the first ONU301 and the second ONU302 may be applied to ONUs on any optical link in an ODN, and may also be applied to ONUs in other ODN embodiments.

The embodiment of the application also provides a method for identifying the optical link where the ONU is located in the PON system. As shown in fig. 19, the method includes:

in step S10, the OLT sends down the test lights with Q wavelengths, where Q is an integer greater than or equal to 1, and the first optical link between the OLT and the first ONU301 has a specific transmittance for the test lights with at least one wavelength. It is understood that the specific transmittance of the optical link for the test light can be referred to the description of the optical filtering structure 210 in the above embodiment for filtering the optical signal with a specific transmittance, and is not described herein again.

In one embodiment, Q is at least equal to the number of wavelength classes of the optical signal filtered by the first optical link. As shown in fig. 14, the optical filtering structure 210 is not disposed in the optical output section 200 of the first-stage optical splitter where the first optical link is located, and the optical output section 200 of the second-stage optical splitter where the first optical link is located can filter optical signals with

wavelengths

3 and 4, so that the number of the wavelengths of the optical signals that can be filtered by the first optical link is 2, that is, Q is at least equal to 2, and the OLT at least sends test light with

wavelengths

3 and 4 downstream.

In another embodiment, Q is equal to the number of wavelength categories of the optical signals filtered by all optical links in the ODN. As shown in fig. 14, the ODN can filter optical signals of wavelength 1, wavelength 2, wavelength 3 and wavelength 4, so the OLT can send test light of wavelength 1, wavelength 2, wavelength 3 and wavelength 4 downstream. I.e. Q is equal to 4. The following examples are described with Q ═ 4 as an example.

In one embodiment, at least one optical filtering structure is disposed on the first optical link, and one optical filtering structure filters test light of one wavelength with a specific transmittance. The first optical link, where ONU1 is located in fig. 14, filters wavelength 3 with transmission 0%, and filters wavelength 4 with transmission 0%.

It is understood that there is also a special case that when the optical filter structure 210 is not provided on one optical link, the first optical link has a specific transmittance for the test light, which is understood to mean that the transmittance of the first optical link for each wavelength of the test light is 100%. Typically, there is at most one such optical link in each ODN.

In one embodiment, Q is greater than or equal to 2, and step S10 includes: and the OLT sequentially sends the test lights with the Q wavelengths downwards according to the time sequence.

In step S20, the first ONU301 receives the test lights of Q wavelengths transmitted from the OLT. In one embodiment, Q is greater than or equal to 2, and step S20 includes: and the ONU sequentially receives the test lights with the Q wavelengths sent by the OLT according to the time sequence.

In step S30, the first ONU301 determines the reception power value of the received test light of each wavelength.

In step S40, the first ONU301 generates feedback information indicating the reception power value of the test light.

In step S50, the first ONU301 transmits the feedback information to the OLT.

In one embodiment, the feedback information may be a plurality of pieces, and one piece of the feedback information indicates the reception power value of the test light of one wavelength. In another embodiment, the feedback information may be one piece, one piece of feedback information indicating the reception power values of the test lights of the Q wavelengths. Or in another embodiment, the feedback information may be a plurality of pieces, one piece of the feedback information indicating the reception power values of the test lights of at least 2 (less than Q) wavelengths.

In step S60, the OLT receives feedback information fed back by the first ONU 301.

In step S70, the OLT determines the transmittance from the reception power value of the test light of at least one wavelength. The method comprises the following steps:

the first method is as follows: the reception power value of the test light received by the OLT includes, in addition to the reception power value of the test light having a specific transmittance on the first optical link, the reception power value of the test light having a full transmittance on the first optical link, and the method further includes: the OLT determines the maximum value among the received plurality of reception power values as a reference reception power value P0, and step S70 includes: the OLT determines the transmissivity of the test light with at least one wavelength in the first optical link according to the receiving power value and the reference receiving power value of the test light with at least one wavelength.

The OLT may regard a reception power value P1 smaller than P0 as a reception power value of the test light having a specific transmittance on the first optical link. The transmission may be equal to 10^ (P1/10)/10^ (P0/10), for example. For example, for the first optical link where the second ONU302 is located shown in fig. 14, the transmittance at wavelength 3 is 50%, and the transmittance at wavelength 4 is 50%.

The second method comprises the following steps: the method further comprises the following steps: OLT sends down business light signal; the ONU receives the service optical signal, the ONU determines a service optical receiving power value of the service optical signal, and the ONU transmits service optical information to the OLT, wherein the service optical information is used for indicating the service optical receiving power value of the service optical signal.

The OLT receives service optical information fed back by the first ONU 301; the OLT determines the transmissivity of the test light with at least one wavelength in the first optical link according to the receiving power value of the test light with at least one wavelength and the receiving power value of the service light.

The service light receiving power value in this manner has a full transmittance on the first optical link, which is similar to P0 in the first manner, and the calculation formula of the transmittance is the same as the first manner, and is not described herein again.

In step S80, the OLT determines that the first ONU301 is located in the first optical link according to the relationship between the optical link and the wavelength and the transmittance, and the at least one wavelength and the determined transmittance.

In one embodiment, the OLT internally maintains the relationship between each optical link and the wavelength and transmittance. In one embodiment, the optical links may be characterized by optical link numbers, e.g., 64 optical links are included in fig. 14, and there are a total of 64 optical link numbers. In another embodiment, the optical link may be further characterized by an optical splitter level and an optical splitter port number, for example, for the first optical link where the first ONU301 shown in fig. 14 is located, it may be characterized as: a first splitter port 1 and a second splitter port 4. The relationship between the first optical link and the wavelength and transmittance may be: the transmittance of the first-stage optical splitter port 1 and the second-stage optical splitter port 4 is 0% at the

wavelength

3 and 0% at the wavelength 4.

When the above step S80 is executed, the OLT further knows which wavelength of the test light has the received power value. The method further comprises the step that the OLT determines the wavelength of the test light corresponding to the receiving power value. The method comprises the following steps:

the first method is as follows: after the OLT sends the test light with one wavelength downstream each time, the OLT waits to receive feedback information fed back by the first ONU 301;

after receiving the test light with one wavelength each time, the ONU determines a reception power value of the test light and generates feedback information, and sends the feedback information to the OLT, where the feedback information indicates the reception power value of the test light.

After receiving the feedback information, the OLT sends the test light of the next wavelength downstream. The ONU receives the test light of the next wavelength, and the ONU repeats the steps of generating and transmitting the feedback information. Therefore, the wavelength of the test light transmitted before the time when the OLT receives the feedback information is the wavelength of the test light corresponding to the reception power value indicated by the feedback information. The embodiment does not need to occupy additional information to indicate the wavelength, and the wavelength can be judged directly according to the time sequence. No additional changes to the information format are required.

The second method comprises the following steps: after the OLT sequentially sends the test lights with the Q wavelengths downwards according to the time sequence, the ONU sequentially receives the test lights with the Q wavelengths according to the time sequence, determines the receiving power values of the Q wavelengths respectively, and records the receiving time sequence of the test lights with the Q wavelengths.

In an embodiment, the ONU may send Q pieces of feedback information to the OLT, each piece of feedback information indicating a reception power value of one wavelength. And the ONU sequentially sends the corresponding Q pieces of feedback information according to the receiving time sequence of the test light with various wavelengths. The OLT can determine the wavelength of the corresponding test light according to the time sequence of the received feedback information.

In another embodiment, the ONU may send a piece of feedback information to the OLT, the feedback information indicating the reception power values of the Q wavelengths and the reception timing of the test lights of the Q wavelengths.

The third method comprises the following steps: each of the Q types of wavelength test lights sent downstream by the OLT carries a label, wherein the labels carried by any two types of wavelength test lights are different; the feedback information is used for indicating the receiving power value of the test light and a label carried in the test light corresponding to the receiving power value; the method further comprises the following steps: and the OLT determines the wavelength of the test light corresponding to the receiving power value according to the label. In the mode, the OLT sends the test light and the ONU sends the feedback information without being limited by the time sequence, so that the method is flexible to realize.

Further, the method may further include: the OLT transmits optical link information indicating the first optical link. The OLT may send optical link information to other servers. The optical link information is specifically used to indicate the optical splitters and ports of the optical splitters located on the first optical link. For example, the optical link information includes identification information of each optical splitter in each optical splitter stage, and identification information of each port located on the first optical link.

In the above embodiment, the ONU feeds back the reception power value to the OLT, and the OLT determines the transmittance according to the reception power value, and further determines the optical link information. It is to be understood that, in another embodiment, the ONU may also determine the transmittance according to the reception power value, feed back the transmittance to the OLT (for example, feedback information is used to indicate the transmittance), and determine the optical link information by the OLT, and other details may refer to the above embodiment and are not described herein again. Or, in another embodiment, the ONU may determine the transmittance according to the reception power value, and further determine the optical link information, and then the ONU feeds back the optical link information to the OLT (for example, the feedback information is used to indicate the optical link information).

The present invention also provides an OLT400 as described in the various embodiments above. As shown in fig. 20, OLT400 comprises a processor 410 and a transceiver 420.

The transceiver 420 includes an optical transmitter and an optical receiver. The optical transmitter converts the electrical signal into an optical signal and transmits the optical signal to the ODN, and the optical receiver receives the optical signal from the ODN network and converts the optical signal into an electrical signal. The light emitter may be implemented by a light emitting device such as a gas laser, a solid laser, a liquid laser, a semiconductor laser, a direct modulation laser, or the like. The optical receiver may be implemented by a photodetector, such as a photodetector or a photodiode (e.g., an avalanche diode), etc.

The transceiver 420 may be an optical module. The light module may further comprise a control circuit. The optical transmitter has a wavelength tunable function, and may be a Distributed Bragg Reflector (DBR) laser, a group of Distributed Feedback Bragg (DFB) lasers, or other types. The optical module may include an optical transmitter that transmits both the traffic wavelength and the test wavelength.

Alternatively, the optical module may also include two optical transmitters, one optical transmitter for transmitting the service light and the other optical transmitter for transmitting the test light.

The processor 410 is configured to implement the functions of ONU management, DBA (Dynamic Bandwidth Allocation), ONU registration, data transceiving, and the like. The Processor 410 may be implemented by a hardware Circuit, a software program, or a combination of hardware and software, such as a Field-Programmable Gate Array (FPGA), an Application-Specific Integrated Circuit (ASIC), a System on Chip (SoC), a Media Access Control (MAC), a Central Processing Unit (CPU), a Network Processor (NP), a Digital Signal Processing (DSP), a Microcontroller (MCU), or a Programmable Logic Device (PLD), or other Integrated chips. Processor 410 may perform, for example, the above-described determining a transmittance, determining a reference received power value P0, determining an optical link, and/or the like.

OLT400 further includes a Memory 430, which may be a Read Only Memory (ROM), a static Memory device, a dynamic Memory device, or a Random Access Memory (RAM), a register, or a non-volatile Memory (non-volatile Memory), such as a flash Memory, or at least one disk Memory. When the technical solution provided by the embodiment of the present invention is implemented by software or firmware, a program code for implementing the technical solution provided by the embodiment of the present invention is stored in the memory 430 and executed by the processor 410.

The memory 430 and the Processor 410 may be located on different physical entities, or may be partially or completely Integrated on one physical entity, where the physical entity may be a Field-Programmable Gate Array (FPGA), an Application-Specific Integrated Circuit (ASIC), a System on Chip (SoC), a Central Processing Unit (CPU), a Network Processor (NP), a Digital Signal Processor (DSP), a Microcontroller (MCU), or a Programmable Logic Device (PLD), or other Integrated chips.

OLT400 further includes a Wavelength Division Multiplexing (WDM) unit 440. The wavelength division multiplexer is connected to transceiver 420 and acts as a multiplexer when OLT400 transmits an optical signal. When OLT400 receives an optical signal, the wavelength division multiplexer acts as a demultiplexer. Wavelength division multiplexers may also be referred to as optical couplers.

It is understood that wavelength division multiplexer 440 may also exist independently of OLT 400.

According to the above embodiment, OLT400 shown in fig. 20 performs steps S10, S60, S70, S80 in the embodiment shown in fig. 19. Specifically, the processor 410 executes steps S70, S80. The transceiver 420 performs steps S10, S60. Further details of the steps performed by the processor 410 and the transceiver 420 can be obtained from the description of the embodiments of the method and the drawings, and are not repeated herein. Likewise, OLT400 has corresponding advantages to those of the above-described method embodiments, and is not described herein again.

It is understood that OLT400 described above may also include other components, which are not described in detail herein.

The present invention further provides an ONU300 according to the above embodiments. As shown in fig. 21, ONU300 comprises a processor 310 and a transceiver 320.

The transceiver 320 includes an optical transmitter and an optical receiver. The optical transmitter converts the electrical signal into an optical signal and transmits the optical signal to the ODN, and the optical receiver receives the optical signal from the ODN network and converts the optical signal into an electrical signal. The light emitter may be implemented by a light emitting device such as a gas laser, a solid laser, a liquid laser, a semiconductor laser, a direct modulation laser, or the like. The optical receiver may be implemented by a photodetector, such as a photodetector or a photodiode (e.g., an avalanche diode), etc.

The transceiver 320 may be an optical module. The light module includes a light assembly and a control circuit. Alternatively, the transceiver 320 may be an optical component.

The optical assembly includes an optical transmitter and an optical receiver. The optical assembly may include an optical transmitter and an optical receiver for receiving the service light and the test light. Or the optical assembly may also comprise an optical transmitter and two optical receivers, wherein one optical receiver is used for receiving the service light and the other optical receiver is used for receiving the test light.

The processor 310 is configured to implement the functions of management of the ONU300, DBA (Dynamic Bandwidth Allocation), registration of the ONU300, data transceiving, and the like. The Processor 310 may be implemented by a hardware Circuit, a software program, or a combination of hardware and software, such as a Field-Programmable Gate Array (FPGA), an Application-Specific Integrated Circuit (ASIC), a System on Chip (SoC), a Media Access Control (MAC), a Central Processing Unit (CPU), a Network Processor (NP), a Digital Signal processing Circuit (DSP), a Microcontroller (MCU), or a Programmable Logic Device (PLD), or other Integrated chips. The processor 310 may perform, for example, the above-described determination of the reception power values of the test light and the service light, generation of the feedback information and the service light information, and the like.

ONU300 may further include a Memory 330, which may be a Read Only Memory (ROM), a static storage device, a dynamic storage device, or a Random Access Memory (RAM), a register, or a non-volatile Memory (non-volatile Memory), such as a flash Memory, or at least one disk Memory. When the technical solution provided by the embodiment of the present invention is implemented by software or firmware, a program code for implementing the technical solution provided by the embodiment of the present invention is stored in the memory 330 and executed by the processor 310.

The memory 330 and the Processor 310 may be located on different physical entities, or may be partially or completely Integrated on one physical entity, where the physical entity may be a Field-Programmable Gate Array (FPGA), an Application-Specific Integrated Circuit (ASIC), a System on Chip (SoC), a Central Processing Unit (CPU), a Network Processor (NP), a Digital Signal Processor (DSP), a Microcontroller (MCU), or a Programmable Logic Device (PLD), or other Integrated chips.

The ONU300 further includes a Wavelength Division Multiplexing (WDM) device 340. The wavelength division multiplexer 340 is connected to the transceiver 320.

According to the above embodiment, the ONU300 shown in fig. 21 performs steps S20, S30, S40, S50 in the embodiment shown in fig. 19. Specifically, the processor 310 executes steps S30, S40. The transceiver 320 performs steps S20, S50. Further details of the steps performed by the processor 310 and the transceiver 320 can be obtained from the description of the embodiments of the method and the drawings, and are not repeated herein. Similarly, the ONU300 has corresponding beneficial effects to those in the foregoing embodiment of the method, and will not be described herein again.

It is understood that the ONU300 described above may further include other devices, which are not described herein.

The present invention also provides a PON system including OLT400, ONU300, and ODN described in the above embodiments. Reference may be made to the above embodiments, which are not described herein again. Similarly, the PON system has corresponding advantages to those in the foregoing embodiments, and details are not described herein.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

In summary, the above description is only an example of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The optical splitter is characterized by comprising an light incoming section and N light outgoing sections, wherein N is an integer greater than or equal to 2;

each light-emitting section in the at least N-1 light-emitting sections is provided with at least one light filtering structure, and each light filtering structure filters light signals with one wavelength by specific transmissivity;

any two light-emitting sections provided with the light filtering structures meet at least one of the following conditions 1 and 2: condition 1: at least one of the wavelengths being filtered is different; condition 2: the transmittance of optical signals at least one of said wavelengths is different;

and at least two light-emitting sections exist in the light-emitting section provided with the light filtering structure, and the light-emitting section meets the condition 2.

2. The optical splitter of claim 1, wherein one of the N light exiting sections is not provided with the optical filter structure, and at least one light exiting section is provided with the optical filter structure.

3. The optical splitter according to claim 1 or 2, wherein M optical filtering structures are disposed on at least one of the N light-emitting sections, each of the light-emitting sections filters optical signals with M wavelengths, and M is an integer greater than or equal to 2.

4. A spectrometer according to any of claims 1 to 3, wherein the spectrometer is an equal ratio spectrometer or an unequal ratio spectrometer.

5. The optical splitter of claim 4, wherein the N light-exiting sections of the unequal ratio optical splitter include 1 unequal ratio light-exiting section and N-1 equal ratio light-exiting sections, and one of the optical filter structures is disposed on the unequal ratio light-exiting section.

6. The optical splitter according to claim 5, wherein the unequal ratio light-exiting section and any one of the equal ratio light-exiting sections satisfy: said optical filtering structure capable of filtering the same wavelength is absent.

7. The optical splitter according to any one of claims 1 to 6, wherein the optical splitter is a Planar Lightwave Circuit (PLC) splitter, the PLC splitter comprising an optical input end fiber, N optical output end fibers, and a planar lightwave circuit;

the planar optical waveguide comprises an optical input waveguide end, N optical output waveguide ends and a middle branch waveguide connected between the optical input waveguide end and the N optical output waveguide ends;

the light inlet end optical fiber is connected with the light inlet waveguide end, and the light inlet section comprises the light inlet end optical fiber and the light inlet waveguide end;

the N light-emitting end optical fibers are connected with the N light-emitting waveguide ends in a one-to-one correspondence manner;

each light-emitting section comprises the middle branch waveguide, a pair of light-emitting waveguide ends and a light-emitting end optical fiber which are connected with each other.

8. The optical splitter of claim 7, wherein the optical filtering structure is disposed in at least one of the intermediate branch waveguide, the light exit waveguide end, and the light exit end optical fiber.

9. The optical splitter of claim 8 wherein the light exit end fiber comprises a ribbon fiber, the optical filtering structure being disposed on the ribbon fiber;

the optical splitter further comprises a fixed box body, and the fixed box body is used for packaging and fixing the part, provided with the optical filtering structure, of the strip fiber inside the fixed box body.

10. The optical splitter according to any one of claims 1 to 6, wherein the optical splitter is a fused biconical taper optical splitter, the fused biconical taper optical splitter comprises an optical input end fiber, a coupling region fiber and N optical output end fibers, and the optical filtering structure is disposed on the optical output end fibers.

11. The optical splitter according to any one of claims 1 to 10, wherein the light filtering structure is a segment of a grating or the light filtering structure is a filter film.

12. An Optical Distribution Network (ODN) is characterized by comprising a primary optical splitter and a secondary optical splitter;

the first-stage optical splitter is the optical splitter according to any one of claims 1 to 11, and an optical input section of the first-stage optical splitter is referred to as a first optical input section, and an optical output section of the first-stage optical splitter is referred to as a first optical output section;

the secondary optical splitter is the optical splitter according to any one of claims 1 to 11, and an optical input section of the secondary optical splitter is referred to as a second optical input section, and an optical output section of the secondary optical splitter is referred to as a second optical output section;

the first light-emitting section is connected with the second light-emitting section;

the first light-in section, the first light-out section and the second light-in section which are connected with each other, and the second light-out section form an optical link;

any two of the optical links satisfy at least one of the following conditions 1 and 2: condition 1: at least one of the wavelengths being filtered is different; condition 2: the transmittance of optical signals at least one of said wavelengths is different;

wherein there are at least two of the optical links that satisfy the condition 2.

13. The ODN of claim 12, wherein the primary and secondary splitters are equal ratio splitters, the secondary splitter is a plurality of secondary splitters, each of the secondary splitters is the same splitter, and any primary and any secondary splitters are different splitters.

14. The ODN of claim 13, wherein any one of the first light exiting sections and any one of the second light exiting sections satisfies: said optical filtering structure capable of filtering the same wavelength is absent.

15. The ODN of claim 12, wherein said primary beamsplitter and said secondary beamsplitter are each anisometric beamsplitters;

the light-emitting section of the unequal ratio light splitter comprises 1 unequal ratio light-emitting section and N-1 equal ratio light-emitting sections;

the unequal light-emitting section of the first-level light splitter is connected with the light-entering section of the second-level light splitter.

16. The ODN of claim 15, wherein the primary beamsplitter and the secondary beamsplitter are the same unequal ratio beamsplitter; and the unequal ratio light-emitting section of the unequal ratio light splitter and any equal ratio light-emitting section meet the following requirements: said optical filtering structure capable of filtering the same wavelength is absent.

17. A method for identifying an optical link in which an Optical Network Unit (ONU) is located in a Passive Optical Network (PON) system, the method comprising:

the OLT sends test light with Q wavelengths downstream, wherein Q is an integer greater than or equal to 1, and a first optical link between the OLT and a first ONU has specific transmissivity to the test light with at least one wavelength;

the OLT receives feedback information fed back by the first ONU, wherein the feedback information is used for indicating the receiving power value of the test light;

the OLT determines the transmissivity according to the receiving power value of the test light with at least one wavelength;

and the OLT determines that the first ONU is positioned in the first optical link according to the relation between the optical link and the wavelength and the transmissivity, and the at least one wavelength and the determined transmissivity.

18. The method of claim 17, wherein Q is greater than or equal to 2, and wherein sending test light of Q wavelengths downstream by the OLT comprises: the OLT sequentially sends the test lights with the Q wavelengths downwards according to a time sequence;

after the OLT sends the test light with one wavelength downstream each time, waiting for receiving the feedback information fed back by the first ONU; and after receiving the feedback information, the OLT sends the test light with the next wavelength in a downlink.

19. The method of claim 17, wherein each of the Q wavelengths of test light sent downstream by the OLT carries a label, wherein the labels carried by any two wavelengths of test light are different;

the feedback information is used for indicating the receiving power value of the test light and the label carried in the test light;

the method further comprises the following steps: and the OLT determines the wavelength of the test light corresponding to the receiving power value according to the label.

20. The method of any of claims 17 to 19, further comprising:

the OLT sends a service optical signal downstream;

the OLT receives service optical information fed back by the first ONU, wherein the service optical information is used for indicating a service optical receiving power value of the service optical signal;

and the OLT determines the transmissivity of the test light with at least one wavelength in the first optical link according to the receiving power value of the test light with at least one wavelength and the receiving power value of the service light.

21. The method of any of claims 17 to 20, further comprising:

the OLT transmits optical link information, wherein the optical link information is used for indicating the first optical link.

22. The method of claim 21 wherein said optical link information includes identification information for each of said optical splitters in said stages of optical splitters and identification information for each of said ports located on said first optical link.

23. A method according to any one of claims 17 to 22, wherein the PON system comprises an optical distribution network, ODN, according to any one of claims 12 to 16.

24. A method for identifying an optical link in which an Optical Network Unit (ONU) is located in a Passive Optical Network (PON) system, the method comprising:

an Optical Network Unit (ONU) receives test light with Q wavelengths sent by a light line terminal (OLT), wherein Q is an integer greater than or equal to 1, and a first optical link between the OLT and the ONU has specific transmissivity on the test light with at least one wavelength;

the ONU determines a reception power value of the test light for each wavelength received;

and the ONU sends feedback information to the OLT, wherein the feedback information is used for indicating the receiving power value of the test light.

25. The method of claim 24, wherein Q is greater than or equal to 2, and the ONU receiving the test lights of Q wavelengths transmitted by the OLT comprises: the ONU sequentially receives the test lights with the Q wavelengths sent by the OLT according to a time sequence;

after receiving the test light of one wavelength, the ONU sends feedback information to the OLT, where the feedback information is used to indicate a reception power value of the test light of the one wavelength; and after transmitting the feedback information, the ONU receives the test light of the next wavelength.

26. The method according to claim 24, wherein each of the Q wavelengths of test light received by the ONU carries a label, wherein the labels carried by any two wavelengths of test light are different; the ONU transmitting the determined reception power value of the test light of each wavelength to the OLT includes:

and the ONU sends feedback information to the OLT, wherein the feedback information is used for indicating the receiving power value of the test light and indicating the label carried in the test light.

27. The method of any one of claims 24 to 26, further comprising:

the ONU receives a service optical signal sent by the OLT;

the ONU determines a service optical receiving power value of the service optical signal;

and the ONU sends service optical information to the OLT, wherein the service optical information is used for indicating the service optical receiving power value of the service optical signal.

28. A method according to any one of claims 24 to 27, wherein the PON system comprises an optical distribution network, ODN, according to any one of claims 12 to 16.

29. An optical line terminal, OLT, comprising a transceiver and a processor;

the transceiver is configured to send test light with Q wavelengths downstream, where Q is an integer greater than or equal to 1, and a first optical link between the OLT and a first ONU has a specific transmittance for the test light with at least one wavelength;

the transceiver is further configured to receive feedback information fed back by the first ONU, where the feedback information is used to indicate a reception power value of the test light;

the processor is used for determining the transmissivity according to the receiving power value of the test light with at least one wavelength;

the processor is further configured to determine that the first ONU is located on the first optical link according to the relationship between the optical link and the wavelength, the transmittance, and the at least one wavelength and the determined transmittance.

30. The OLT of claim 29, wherein Q is greater than or equal to 2, and wherein said transceivers sequentially downstream transmit said test lights at said Q wavelengths in a time sequence;

after the transceiver sends the test light with one wavelength in a downlink manner each time, waiting for receiving the feedback information fed back by the first ONU; and after receiving the feedback information, the transceiver sends the test light with the next wavelength in a downlink manner.

31. The OLT of claim 29 or 30, wherein the transceiver is further configured to send optical link information indicating the first optical link, the optical link information comprising identification information for each of the optical splitters in the respective stages of optical splitters and identification information for each of the ports located on the first optical link.

32. An optical network unit, ONU, comprising a transceiver and a processor;

the transceiver is used for receiving test light with Q wavelengths sent by an Optical Line Terminal (OLT), wherein Q is an integer greater than or equal to 1, and a first optical link between the OLT and the ONU has a specific transmissivity to the test light with at least one wavelength;

the processor is used for determining the received power value of the test light of each wavelength received;

the transceiver is further configured to send feedback information to the OLT, where the feedback information is used to indicate a reception power value of the test light.

33. The ONU of claim 32, wherein Q is greater than or equal to 2, and the transceiver sequentially receives the test lights with Q wavelengths transmitted from the OLT in time series;

wherein, after receiving the test light of one wavelength, the transceiver sends feedback information to the OLT, the feedback information being used to indicate a reception power value of the test light of the one wavelength; and after transmitting the feedback information, the transceiver receives the test light of a next wavelength.

34. The ONU of claim 32 or 33,

the transceiver is further configured to receive a service optical signal sent by the OLT;

the processor is further configured to determine a service optical reception power value of the service optical signal;

the transceiver is further configured to send service optical information to the OLT, where the service optical information is used to indicate a service optical receiving power value of the service optical signal.

35. A passive optical network, PON, system, characterized in that the PON system comprises an optical line termination, OLT, according to any of claims 29 to 31, an optical network unit, ONU, according to any of claims 32 to 34, and an optical distribution network, ODN, according to any of claims 12 to 16.