WO2015100543A1

WO2015100543A1 - Optical signal transmitter, receiver and method for modulation and demodulation

Info

Publication number: WO2015100543A1
Application number: PCT/CN2013/090913
Authority: WO
Inventors: 周雷; 彭桂开
Original assignee: 华为技术有限公司
Priority date: 2013-12-30
Filing date: 2013-12-30
Publication date: 2015-07-09
Also published as: CN104981992A; CN104981992B

Abstract

The embodiments of the present invention provide an optical signal transmitter and receiver, terminal, and method for modulation and demodulation. The optical signal receiver includes a polarization beam splitter, a first modulation module, a second modulation module and a polarization beam combiner. The polarized light output from a light source is separated by the polarization beam splitter into a first polarization light and a second polarization light with orthogonal polarization. A first polarization signal is generated from the first polarization light modulated with a first data signal by the first modulation module. A second polarization signal is generated from the second polarization light modulated with a second data signal and the optical carrier is suppressed by the second modulation module. The first polarization signal and the second polarization signal are combined into an optical polarization multiplexing signal by the polarization beam combiner. The embodiments of the present invention improve the system capacity.

Description

Optical signal transmitter, receiver, and modulation and demodulation method

TECHNICAL FIELD The present application relates to the field of optical communication technologies, and more particularly to an optical signal transmitter, a receiver, an optical line terminal, an optical network unit, a passive optical network system, and a modulation and demodulation method. BACKGROUND A passive optical network is a pure medium network, and there is no active electronic device between an optical line terminal and an optical network terminal, thereby avoiding electromagnetic interference and lightning impact of external devices, and reducing faults of lines and external devices. The rate increases the reliability of the system, so the primary key becomes the mainstream technology in the field of broadband access.

In a passive optical network system, terminals communicate via optical fibers, and optical signals are used to transmit data. In the process of implementing the present invention, the inventors have found that with the rapid development of various broadband services and the like, people have higher and higher requirements on system capacity. Therefore, in a passive optical network system, how to improve system capacity has become a field in the field. The technical problems that technicians urgently need to solve.

Summary of the invention

In view of this, the present application provides an optical signal transmitter, a receiver, a machine terminal, and a modulation and demodulation method to improve system capacity.

To achieve the above objective, the present application provides the following technical solutions:

In a first aspect, an optical signal transmitter is provided, comprising: a polarization beam splitter, a first modulation module, a second modulation module, and a polarization combiner;

The polarization beam splitter output ends are respectively connected to the first modulation module input end and the second modulation module input end; the first modulation module output end and the second modulation module output end are respectively connected to the polarization Combiner input;

The polarized light output by the light source is divided by the polarization beam splitter into first polarization state light and second polarization state light having orthogonal polarization states; the first polarization state light modulates the first data signal via the first modulation module , Generating a first polarization state signal; the second polarization state light modulates the second data signal by the second modulation module, and suppresses the optical carrier to generate a second polarization state signal; the first polarization state signal and the first The polarization state signal is synthesized by the polarization multiplexer via the polarization multiplexer.

In a first possible implementation manner of the first aspect, the first modulation module includes a first modulator and a carrier signal power ratio control module;

The first modulator input end is connected to the polarization beam splitter output end; the first modulator output end is connected to the carrier signal power ratio control module input end; the carrier signal power is connected to the control module output end Said polarization combiner input;

After the first polarization state light is modulated by the first modulator, the first data signal is output to the carrier signal power ratio control module, and the carrier signal power ratio control module adjusts the optical carrier and does not include the optical carrier. After the optical signal is a preset power ratio, a first polarization state signal is formed.

In conjunction with the first aspect or the first possible implementation of the first aspect, a second possible implementation of the first aspect is further provided, the second modulation module includes a second modulator and a first Carrier separation module;

The second modulator input is connected to the polarization beam splitter output; the second modulator output is connected to the first carrier separation module input; the first carrier separation module output is connected to the polarization Combiner input;

After the second polarization state light modulates the second data signal by the second modulator, the optical carrier is separated by the first carrier separation module, and the second polarization state signal formed after the optical carrier is separated is output to the Polarization combiner.

In conjunction with the first aspect or the first possible implementation of the first aspect, a third possible implementation manner of the first aspect is further provided, where the second modulation module includes a splitter, a delay, and Mach-Zehnder modulator MZM;

The first output end of the splitter is connected to the input end of the delayer; the MZM input end is respectively connected to the second output end of the splitter, the output of the delayer, and the output end of the polarization beam splitter The MZM output is connected to the polarization combiner; the second data signal is divided into a first path signal and a second path signal by the splitter; the first road letter Outputting to the MZM modulator; the first path signal is delayed by the delayer and output to the MZM modulator, and modulated by the MZM modulator and the second polarization state light to generate a second Polarization signal.

In conjunction with any of the foregoing possible implementations of the first aspect, a fourth possible implementation manner of the first aspect is further provided, where the carrier signal control ratio module includes a second carrier separation module, an optical amplifier, and a first Optical coupling module;

The second carrier separation module input end is connected to the first modulator output end; the second carrier separation module first output end is connected to the optical amplifier input end; the first optical coupling module input end is respectively a second output of the second carrier separation module and the output of the optical amplifier are connected;

After the first polarization state light is modulated by the first modulator, the first data signal is output to the second carrier separation module, and the filtered optical carrier is output to the light by the second carrier separation module. An amplifier that outputs an optical signal that filters out the optical carrier to the first optical coupling module; and the optical signal filtered by the optical carrier is coupled to the optical carrier passing through the optical amplifier by the first optical coupling module to have a preset power ratio The first polarization state signal.

In a second aspect, an optical signal receiver is provided, including a third carrier separation module, a first optical splitting module, a second optical splitting module, a 90 degree polarization rotating module, a second optical coupling module, and a third optical coupling. The module, the first photoelectric conversion module, and the second photoelectric conversion module:

The first output end of the third carrier separation module is connected to the input end of the first optical branch module; the second output end of the third carrier separation module is connected to the input end of the second optical branch module; The first output end of the optical branching module is connected to the 90-degree polarization rotation module; the input end of the second optical coupling module is respectively connected to the first output end of the first optical branching module and the second optical branching module a second output end; the third optical coupling module input end is respectively connected to the first optical branching module second output end and the 90 degree polarization rotating module output end; the first photoelectric conversion module input end is connected to the a second optical coupling module output end; the second photoelectric conversion module input end is connected to the third optical coupling module output end;

The optical polarization multiplexing signal separates the optical carrier and the optical signal that does not include the optical carrier by using the third carrier separation module; the optical signal is divided into the first optical signal and the second optical signal by the first optical branching module. The optical carrier is divided into a first optical carrier and a second optical carrier by the second optical branching module; wherein the optical polarization multiplexing signal is a first polarization state signal orthogonal to a polarization state and Number with optical carrier a composition of two polarization states;

The first optical carrier and the first optical signal are coupled to the first coupling signal via the second optical coupling module; the second optical carrier is rotated by the 90-degree polarization rotation module The second optical signal is coupled to the second coupled signal via the third optical coupling module;

The first coupled signal demodulates a first data signal via the first photoelectric conversion module; the second coupled signal demodulates a second data signal via the second photoelectric conversion module.

In a first possible implementation manner of the second aspect, the third carrier separation module includes an optical circulator and a carrier optical filter;

The first port of the optical circulator receives the optical polarization multiplexing signal, the second port is connected to the first port of the carrier optical filter, and the third port is connected to the first optical branching module; the carrier optical filter The second port is connected to the second optical branching module;

Outputting the optical polarization multiplexed signal to the carrier optical filter via the second port of the optical circulator; filtering the optical carrier through the carrier optical filter, and outputting the filtered optical carrier to the second optical The branching module reflects the optical signal filtered out of the optical carrier back to the optical circulator, and outputs the optical port to the first optical branching module through the third port of the optical circulator.

In conjunction with the second aspect or the first possible implementation of the second aspect, a second possible implementation manner of the second aspect is further provided, where the second optical splitting module includes an optical splitter, The first power control module and the second power control module:

The optical splitter input end is connected to the second output end of the third carrier separation module; the first output end of the optical splitter is connected to the input end of the first power control module; the optical splitter is second The output end is connected to the input end of the first power control module; the output end of the first power control module is connected to the input end of the second optical coupling module; and the output end of the second power control module is connected to the third optical coupling module Input

The optical carrier separated by the third carrier separation module is divided into a first optical carrier and a second optical carrier by the optical splitter, and the first optical carrier is adjusted by the first power control module. After outputting, the second optical carrier is output after being adjusted by the second power control module.

In a third aspect, an optical signal receiver is provided, including a third optical splitting module, a third photoelectric conversion module, a fourth carrier separation module, a 90-degree polarization rotation module, a fourth optical coupling module, and a fourth Photoelectric conversion module;

The first output end of the third optical branching module is connected to the input end of the third photoelectric conversion module; the second output end of the third optical branching module is connected to the input end of the fourth carrier separation module; The first output end of the carrier separation module is connected to the input end of the 90-degree polarization rotation module; the input end of the fourth optical coupling module is respectively connected to the second output end of the fourth carrier separation module and the output end of the 90-degree polarization rotation module ;

The optical polarization multiplexing signal is divided into a first optical polarization multiplexing signal and a second optical polarization multiplexing signal by the third optical branching module, where the optical polarization multiplexing signal is orthogonal to the polarization state a polarization state signal and a second polarization state signal having no optical carrier;

The first optical polarization multiplexing signal is demodulated by the third photoelectric conversion module to output a first data signal;

The second optical polarization multiplexing signal separates the optical carrier and the optical signal that does not include the optical carrier by using the fourth carrier separation module; the optical carrier is deflected by the 90-degree polarization rotation module, and then passes through the fourth optical coupling module. Coupling with the optical signal, outputting the coupled signal to the fourth photoelectric conversion module to demodulate the second data signal.

In a first possible implementation manner of the third aspect, the fourth carrier separation module includes an optical circulator and a carrier optical filter;

The first port of the optical circulator is connected to the second output end of the third optical branching module, the second port is connected to the first port of the carrier optical filter, and the third port is connected to the fourth optical coupling module; a second port of the carrier optical filter is connected to the 90 degree polarization rotation module;

Transmitting, by the carrier optical filter, the filtered optical carrier to the 90-degree polarization rotation module, The optical signal filtered out of the optical carrier is reflected back to the optical circulator; and outputted to the fourth optical coupling module via the third port of the optical circulator.

In a fourth aspect, an optical line termination is provided, comprising the optical signal transmitter described above and/or the optical signal receiver described above.

In a fifth aspect, an optical network unit is provided, comprising the optical signal transmitter described above and/or the optical signal receiver described above. In a sixth aspect, a passive optical network system is provided, comprising the optical line terminal described above and the optical network unit described above.

In a seventh aspect, an optical signal modulation method is provided, including:

Polarizing light output by the light source is divided into first polarization state light and second polarization state light orthogonal to the polarization state; modulating the first polarization state light to the first data signal to generate a first polarization state signal; Polarizing light modulates the second data signal and suppresses the optical carrier to generate a second polarization state signal;

And integrating the first polarization signal and the second polarization signal into a polarization polarization multiplexed signal orthogonal to the polarization state.

In a first possible implementation manner of the fifth aspect, the first polarization state light is modulated by the first data signal to generate a first polarization state signal;

And modulating the first polarization state light with the first data signal, and adjusting the optical carrier and the optical signal to a preset power ratio to generate a first polarization state signal.

In an eighth aspect, an optical signal demodulation method is provided, including:

Separating the received optical polarization multiplexed signal into an optical carrier and an optical signal not including the optical carrier, wherein the optical polarization multiplexed signal is a first polarization state signal orthogonal to a polarization state and a second polarization state having no optical carrier Signal composition

Dividing the optical carrier into a first optical carrier and a second optical carrier, and dividing the optical signal into a first optical signal and a second optical signal;

Coupling the first optical signal with the first optical carrier into a first coupled signal, and coupling the second optical signal with a second optical carrier that is 90 degrees deflected into a second coupled signal;

Performing photoelectric conversion on the first coupled signal to demodulate the first data signal;

The second coupled signal is photoelectrically converted to demodulate the second data signal.

In a ninth aspect, an optical signal demodulation method is provided, comprising:

Dividing the optical polarization multiplexed signal into the same first polarization multiplexed signal and a second polarization multiplexed signal, wherein the optical polarization multiplexed signal is composed of a first polarization state signal orthogonal to a polarization state and no optical carrier a second polarization state signal composition; Performing photoelectric conversion on the first polarization multiplexed signal to demodulate the first data signal; separating the second polarization multiplexed signal into an optical carrier and an optical signal not including the optical carrier; and the optical carrier performs 90-degree polarization And coupling with the optical signal, and photoelectrically converting the coupled signal to demodulate the second data signal.

In summary, the embodiments of the present application provide an optical signal transmitter, a receiver, a terminal, and a modulation and demodulation method. The optical signal transmitter is composed of a polarization beam splitter, a first modulation module, a second modulation module, and a polarization multiplexing wave. The polarization beam splitter divides the polarized light output by the light source into first polarization state light and second polarization state light whose polarization states are orthogonal, and the first polarization state light is modulated by the first modulation module to generate the first data signal. a first polarization state signal, the second polarization state light modulates the second data signal by the second modulation module, and after suppressing the optical carrier, generating a second polarization state signal, wherein the first polarization state signal and the second polarization state signal are polarized The device is synthesized into an optical polarization multiplexed signal, and since the one polarization state signal does not have an optical carrier, the data signal can be quickly and conveniently demodulated. The two polarization signals of the optical polarization multiplexed signal are loaded with data signals, which improves the amount of data transmitted during the communication process, thereby increasing the system capacity. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and obviously, in the following description The drawings are merely examples of the present application, and those skilled in the art can obtain other drawings based on the drawings provided without any creative work.

1 is a schematic structural diagram of an embodiment of an optical signal transmitter according to an embodiment of the present disclosure; FIG. 2 is a schematic structural diagram of a second modulation module in an optical signal transmitter according to an embodiment of the present application;

FIG. 3 is a schematic diagram of another structure of a second modulation module in an optical signal transmitter according to an embodiment of the present application; FIG.

FIG. 4 is still another schematic structural diagram of a second modulation module in an optical signal transmitter according to an embodiment of the present disclosure;

FIG. 5 is still another schematic structural diagram of a second modulation module in an optical signal transmitter according to an embodiment of the present disclosure; FIG. 6 is a schematic structural diagram of another embodiment of an optical signal transmitter according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of a carrier signal power ratio control module in an optical signal transmitter according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of a second carrier separation module in an optical signal transmitter according to an embodiment of the present disclosure;

FIG. 7b is another schematic structural diagram of a second carrier separation module in an optical signal transmitter according to an embodiment of the present disclosure;

FIG. 8 is a schematic structural diagram of an embodiment of an optical signal receiver according to an embodiment of the present disclosure; FIG. 9 is a schematic structural diagram of a third carrier separation module in an optical signal receiver according to an embodiment of the present disclosure;

FIG. 10 is a schematic structural diagram of a second optical branching module in an optical signal receiver according to an embodiment of the present disclosure;

FIG. 11 is a schematic structural diagram of another embodiment of an optical signal receiver according to an embodiment of the present disclosure;

FIG. 12 is a schematic structural diagram of a fourth carrier separation module in an optical signal receiver according to an embodiment of the present disclosure;

FIG. 13 is a flowchart of an embodiment of an optical signal modulation method according to an embodiment of the present disclosure; FIG. 14 is a flowchart of another embodiment of an optical signal demodulation method according to an embodiment of the present application;

FIG. 15 is a flow chart of still another embodiment of an optical signal demodulation method according to an embodiment of the present application. The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present application. It is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. example. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without the creative work are all within the scope of the present application.

One of the main ideas of the embodiments of the present application includes: The optical signal transmitter is composed of a polarization beam splitter, a first modulation module, a second modulation module and a polarization combiner. The polarization beam splitter divides the polarization light output by the light source into first polarization states of light and orthogonal to the polarization state. The second polarization state light is modulated by the first modulation module to generate a first polarization state signal, and the second polarization state light is modulated by the second modulation module to modulate the second data signal, and the optical carrier is suppressed Generating a second polarization state signal, wherein the first polarization state signal and the second polarization state signal are synthesized into a polarization polarization multiplexed signal by a polarization combiner, wherein the polarization polarization multiplexed signal does not have an optical carrier because of one polarization state signal, Data signals can be demodulated quickly and easily. The two polarization signals of the optical polarization multiplexed signal are loaded with the data signal, which improves the amount of data transmitted during the communication process, thereby improving the system capacity. The technical solutions of the present application are described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of an embodiment of an optical signal transmitter according to an embodiment of the present application. The optical signal transmitter can include:

Polarization beam splitter 101, first modulation module 102, second modulation module 103, and polarization combiner

104.

The output ends of the polarization beam splitter 101 are respectively connected to the input ends of the first modulation module 102 and the second modulation module 103; the input ends of the polarization combiner 104 are connected to the outputs of the first modulation module 102 and the second modulation module 103, respectively.

The polarized light output by the light source is divided by the polarization beam splitter 101 into first polarization state light and second polarization state light in which polarization states are orthogonal;

The first polarization state light modulates the first data signal by the first modulation module 102 to generate a first polarization state signal;

The second polarization state light modulates the second data signal by the second modulation module 103, and suppresses the optical carrier to generate a second polarization state signal;

The first polarization state signal and the second polarization state signal are combined by the polarization combiner 104 to form a light polarization multiplexed signal.

The light source may specifically be a laser, and the laser may output linearly polarized light, and the linearly polarized light may be used to transmit data when performing optical fiber communication.

Polarization Beam Splitter (PBS) can divide the polarized light into two beams with orthogonal polarization states, that is, the two beams are perpendicular to each other. Specifically, the incident polarized light can be directed to two perpendiculars. Projecting in a straight direction, decomposing two perpendicular polarization states, the incident polarized light is at 45 degrees to the principal axis of the polarization beam splitter, so that the two polarization states have the same optical power.

In contrast to the polarizing beam splitter, a polarization combiner (PBC) can combine two beams while still maintaining an orthogonal state.

The first data signal and the second data signal are data to be transmitted, and can be loaded onto the polarized light by modulation to become an optical signal, and the first polarization state signal and the second polarization state signal are modulated optical signals.

Wherein, the second polarization state signal does not have an optical carrier, that is, during the modulation process, the optical carrier is suppressed to form an optical signal without an optical carrier.

The first polarization state signal and the second polarization state signal are combined by a polarization combiner to generate an optical polarization multiplexed signal, and the orthogonal state is maintained.

In the embodiment of the present application, the polarized light output by the light source is divided into the first polarization state and the second polarization state in which the polarization state is orthogonal, and the polarization is modulated on the two polarization states. The data signal, which generates a light polarization multiplexed signal, can increase the capacity of the system by a factor of two due to the increased data loading.

The generated optical polarization multiplexed signal can be sent to the receiving end. Since one polarization state signal of the optical polarization multiplexed signal does not have an optical carrier, the receiving end can conveniently and quickly demodulate the first data signal and the second data signal. This increases the amount of data transferred during communication, thereby increasing system capacity.

The first modulation module may be specifically a modulator for loading the first data signal onto the first polarization state light to form a first polarization state signal. Of course, the first modulation module can also be implemented in other manners, which will be described in detail in the following embodiments. The second modulation module modulates the second data signal and suppresses the optical carrier to generate a second polarization state signal without a carrier. There may be multiple possible implementations.

In a possible implementation manner, referring to FIG. 2, FIG. 2 is a schematic structural diagram of a second modulation module in an optical signal transmitter according to an embodiment of the present application.

Referring to FIG. 2, the second modulation module 103 includes a second modulator 113 and a first carrier separation module.

123.

An input of the second modulator 113 is coupled to an output of the polarization beam splitter 101;

The input end of the first carrier separation module 123 is connected to the output end of the second modulator 114, and the output end The polarization combiner 104 is connected.

Therefore, the second polarization state light split by the polarization beam splitter 101 specifically modulates the second data signal by the second modulator 113, and the second polarization state light modulates the second data signal to become the optical signal, and then passes through the first The carrier separation module 123 separates the optical carrier, and then outputs the optical signal separated from the optical carrier, that is, the second polarization state signal, to the polarization combiner 104.

The first carrier separation module can separate the optical carriers in the optical signal, so that the optical signals are divided into optical carriers and optical signals that do not include optical carriers.

The optical carrier separated by the first carrier separation module is discarded.

The first carrier separation module may also have multiple possible implementation manners. In a possible implementation manner, the first carrier separation module is specifically an optical filter, and the optical filter has a transmitted optical carrier reflected optical signal or transmitted light. The signal reflects the function of the optical carrier. In order to distinguish between different types of optical filters, in the embodiment of the present application, an optical filter capable of transmitting an optical carrier reflected optical signal is named as a carrier optical filter, and an optical filter that transmits the optical carrier reflected optical carrier is named as a signal. Optical filter; In the embodiment of the present application, a signal optical filter having a function of transmitting a light carrier of the transmitted optical signal may be selected.

Therefore, the filtered optical carrier can be reflected from the input end through the signal optical filter, and the optical signal of the optical carrier wave is filtered out, that is, the second polarization state signal is output from the output end. In another possible implementation manner, referring to FIG. 3, another structural diagram of the second modulation module in the optical signal transmitter provided by the embodiment of the present application is shown.

Referring to FIG. 3, the second modulation module 103 includes a second modulator 113 and a first carrier separation module.

123. The first carrier separation module 123 includes an optical circulator 100 and a signal optical filter 200.

The first port of the optical circulator 100 is coupled to the output of the second modulator 113, the second port is coupled to the first port of the signal optical filter 200, and the second port of the signal optical filter 200 is coupled to the polarization combiner 104.

The second polarization state light split by the polarization beam splitter 101 is specifically modulated by the second modulator 113 and output to the signal light filter 200 via the optical circulator 100. The signal optical filter 200 filters out the optical carrier and outputs a second polarization state signal formed after filtering the optical carrier to the polarization combiner 104.

The optical circulator is an optical device with multiple ports, which allows light to enter from one port, only Output from another port.

The optical filter selects a signal optical filter that reflects the optical carrier of the transmitted optical signal.

Therefore, in the embodiment of the present application, the second polarization state light modulates the second data, enters the optical circulator 100 from the first port, and outputs the second port to the first port of the signal optical filter 200; the signal optical filter 200 The filtered optical carrier is reflected back from the first port to the optical circulator, and the second polarization state signal filtered out of the optical carrier is output from the second port.

The optical carrier reflected into the optical circulator can be output from other ports of the optical circulator and discarded. Of course, the optical filter may also select a carrier optical filter that transmits the optical carrier and reflects the optical signal. Referring to FIG. 4, a schematic diagram of still another structure of the second modulation module in the optical signal transmitter provided by the embodiment of the present application is shown.

Referring to FIG. 4, the second modulation module 103 can include an optical circulator 300 and a carrier optical filter.

400.

The first port of the optical circulator 300 is connected to the output of the second modulator 113, the second port is connected to the carrier optical filter 400, and the third port is connected to the polarization combiner 104.

The second polarization state light split by the polarization beam splitter 101 is specifically modulated by the second modulator 113 and output to the carrier optical filter 200 via the optical circulator 300. The carrier optical filter 200 filters out the optical carrier and outputs a second polarization state signal formed after filtering the optical carrier to the polarization combiner 104.

Outputted to the carrier optical filter 400 via the optical circulator 300, via the carrier optical filter

400 filters out the optical carrier, and reflects the second polarization state signal formed after filtering the optical carrier back to the optical circulator 300, and outputs the third port through the optical circulator 300.

The optical carrier filtered by the carrier optical filter 400 can be discarded. In yet another possible implementation, referring to FIG. 5, a schematic structural diagram of a second modulation module in the optical signal transmitter provided by the embodiment of the present application is shown.

Referring to FIG. 5, the second modulation module 103 can include:

Splitter 501, delay 502, and MZM503 (Mach-Zehnder Modulator, Mach

- Zeng Del modulator :). The first output of the splitter 501 is connected to the input end of the delay 502;

The MZM 503 is connected to the output of the delay 502, the output of the optical splitter 501, and the output of the polarization beam splitter 101, respectively.

The second data signal is divided into a first path signal and a second path signal by the splitter 501; the first path signal is directly output to the MZM 503; the first path signal is timed by the delay 503 After the delay, it is output to the MZM 503; the second polarization state light is also output to the MZM 503, so that by the MZM 503 modulation, a second polarization state signal without an optical carrier can be generated.

The splitter can split the signal into two identical signals. The first signal is delayed by a delay, specifically a delay time π such that the delay between the first signal and the second signal is π, so that the optical carrier can be suppressed when modulated by ΜΖΜ. FIG. 6 is a schematic structural diagram of another embodiment of an optical signal transmitter according to an embodiment of the present disclosure, where the optical signal transmitter may include:

A polarization beam splitter 101, a first modulation module 102, a second modulation module 103, and a polarization combiner 104 are provided. For the specific connection manner, refer to the description in the corresponding embodiment in FIG. 1.

The embodiment is different from the embodiment corresponding to FIG. 1 in that the first modulation module 102 can specifically include:

The first modulator 112 and the carrier signal power ratio control module 122.

An input end of the first modulator 112 is connected to the polarization beam splitter 101, and an output end is connected to an input end of the carrier signal power ratio control module 122. The carrier signal power is connected to the output end of the control module 122. Wave filter 104.

The carrier signal power ratio control module can adjust the power ratio between the optical carrier and the optical signal not including the optical carrier. The carrier signal power ratio control module can modulate the optical carrier and the optical signal not including the optical carrier to a preset power ratio.

Therefore, the first polarization state light split by the polarization beam splitter 101 is modulated by the first modulator 112; the optical signal formed after the first data signal is modulated, and output to the carrier signal power ratio control module 122, the carrier signal After the power ratio control module adjusts the optical carrier and the optical signal including the optical carrier to a preset power ratio, the first polarization state signal is formed. The first polarization state signal is a first polarization state signal having a preset power ratio. The preset power ratio can be set according to the sensitivity of the receiving end. By adjusting the power ratio, the receiving end can accurately demodulate the loaded first data signal.

In this embodiment, the first polarization state signal is obtained by dividing the polarized light output by the light source into the first polarization state light and the second polarization state light having orthogonal polarization states, and respectively modulating the data signals for the two polarization states. And the second polarization state signal, and then combining the first polarization state signal and the second skew state signal into an optical polarization multiplexing signal, where the optical polarization multiplexing signal includes two orthogonal polarization state signals, so that two data can be carried. Therefore, the system capacity can be increased, and the system capacity can be doubled while maintaining the bandwidth of the photovoltaic device. And by adjusting the power ratio of the optical carrier and the optical signal, the accuracy of demodulation can be improved.

The carrier signal power ratio control module may have multiple implementation manners. In a possible implementation manner, referring to FIG. 7, a carrier signal power ratio control module in the optical signal transmitter provided by the embodiment of the present application is shown. Schematic diagram of the structure.

The carrier signal power ratio control module 122 can include:

The second carrier separation module 701, the optical amplifier 702, and the first optical coupling module 703.

The input end of the second carrier separation module 701 is connected to the output end of the first modulator 112; the first output end of the second carrier separation module 701 is connected to the input end of the optical amplifier 702; the input ends of the first optical coupling module 703 are respectively The second output of the two carrier separation module 701 and the output of the optical amplifier 702 are connected.

Therefore, the first polarization state light modulates the first data signal by the first modulator 112, and the optical signal formed by modulating the first data signal is output to the second carrier separation module 701, and the optical carrier is separated by the second carrier separation module 701. The separated optical carrier is output to the optical amplifier 702 through the first output end, and the optical signal separating the optical carrier is output to the first optical coupling module 703 through the second output terminal; after adjusting the optical carrier power through the optical amplifier 702, the output is output to the first An optical coupling module 703; the first optical coupling module 703 couples the optical carrier after adjusting the power and the optical signal of the separated optical carrier to form a first polarization having an optical carrier, and the optical carrier and the optical signal have a preset power ratio State signal.

The first optical coupling module 703 can be specifically an optical coupler.

The second carrier separation module 701 can be implemented in various possible manners, as shown in FIG. 7a and FIG. 7b. Two schematic diagrams of the second carrier separation module are shown. In FIG. 7a and FIG. b, the second carrier separation module is composed of an optical circulator and an optical filter.

In FIG. 7a, the first port of the optical circulator 711 is connected to the output end of the first modulator 112, the second port is connected to the first port of the signal optical filter 721, and the third port is connected to the optical amplifier 702, and the signal optical filter 721 The second port is connected to the first optical coupling module 703. The signal optical filter 721 can realize the transmitted optical signal and reflect the optical carrier, so that the signal optical filter can reflect the filtered optical carrier back to the optical circulator, output from the third port of the optical circulator, and filter the optical signal of the optical carrier. Output from the second port to the first optical coupling module.

In FIG. 7b, the first port of the optical circulator 731 is connected to the output of the first modulator 112, the second port is connected to the first port of the carrier optical filter 741, and the third port is connected to the first optical coupling module 703; carrier optical filtering The second port of the 741 is coupled to the optical amplifier 702. The carrier optical filter 721 can implement a transmitted optical carrier to reflect the optical signal, so that the carrier optical filter can output the filtered optical carrier from the second port to the optical amplifier, and the optical signal filtered out of the optical carrier is reflected back to the optical circulator. The third port of the optical circulator is output to the first optical coupling module.

The possible implementation of the second modulation module in the optical signal transmitter shown in FIG. 6 can be seen in FIG. 2 to FIG. 5, and details are not described herein again.

The optical signal transmitter provided by the foregoing embodiments can implement the generation of an optical signal carrying data, and the optical signal is used for optical fiber communication, and the generated optical signal is an optical polarization multiplexing signal, which can increase the amount of data carried. Can increase system capacity.

The optical signal transmitter provided by the embodiment of the present application has a simple structure and low requirements on a light source, and a laser can be used.

The optical polarization multiplexing signal includes a first polarization state signal and a second polarization state signal that are orthogonal to the polarization state, and the second polarization state signal is an optical signal that does not have an optical carrier. When the optical signal is demodulated, the first polarization is performed. The energy of the state signal is greater than the energy of the signal of the second polarization state, and after the power adjustment of the carrier signal ratio control module, the energy of the first polarization state signal is much larger than the energy of the second polarization state signal, so that the second The polarization state signal is processed as a noise signal, so that the first data signal modulated by the first polarization state signal can be recovered. And for the second polarization state signal, by the optical carrier rotation, so that the second The polarization state signal is an optical signal having an optical carrier, and the first polarization state signal is an optical signal having no optical carrier, so that the second data signal modulated in the second polarization state signal can also be demodulated.

The structure for demodulating the received optical polarization multiplexed signal can be implemented in various manners. Therefore, the embodiment of the present application further provides an optical signal receiver for demodulating a data signal from the optical polarization multiplexed signal. The possible implementation of the optical signal receiver will be described in detail below with reference to the accompanying drawings.

FIG. 8 is a schematic structural diagram of an embodiment of an optical signal receiver according to an embodiment of the present disclosure, where the optical signal receiver may include:

The third carrier separation module 801, the first optical branching module 802, the second optical branching module 803, the 90-degree polarization rotation module 804, the second optical coupling module 805, the third optical coupling module 806, and the first photoelectric conversion module 807 And a second photoelectric conversion module 808.

The first output end of the third carrier splitting module 801 is connected to the input end of the first optical branching module 802, and the second output end is connected to the input end of the second optical branching module 803;

The first output end of the second optical branching module 803 is connected to the 90-degree polarization rotation module 804; the second optical coupling module 805 is connected to the first output end and the second optical branch of the first optical branching module 802, respectively. a second output of the module 803;

The third optical coupling module 806 is respectively connected to the second output end of the first optical branching module 802 and the output end of the 90 degree polarization rotating module 804;

The first photoelectric conversion module 807 is connected to the output of the second optical coupling module 805; the second photoelectric conversion module 808 is connected to the output of the third optical coupling module 806.

The optical polarization multiplexed signal separates the optical carrier and the optical signal that does not include the optical carrier by the third carrier separation module 801; wherein the optical polarization multiplexed signal is composed of a first polarization state signal orthogonal to a polarization state and does not have light The second polarization state signal of the carrier is composed; the first polarization state signal is loaded with the first data signal, and the second polarization state signal is loaded with the second data signal.

The optical signal is divided into a first optical signal and a second optical signal by the first optical branching module 802. The optical carrier is divided into a first optical carrier and a second optical splitter module 803. a two-way optical carrier; wherein the optical polarization multiplexed signal is composed of a first polarization state signal orthogonal to a polarization state and a second polarization state signal having no optical carrier; The first optical carrier and the first optical signal are coupled to the first coupling signal via the second optical coupling module 805;

The second optical carrier is rotated by the 90-degree polarization rotation module 804 and coupled to the second optical signal via the third optical coupling module 806 as a second coupling signal;

The first coupled signal is demodulated by the first photoelectric conversion module 807 by a first data signal; the second coupled signal is demodulated by the second photoelectric conversion module 808 to a second data signal.

After the carrier separation, rotation, and coupling, the first coupled signal and the second coupled signal each include a first polarization state signal and a second polarization state signal whose polarization states are orthogonal.

In the first coupled signal, the second polarization state signal does not have an optical carrier, and in the second coupled signal, since the optical carrier is rotated by 90 degrees, the first polarization state signal of the coupled signal does not have an optical carrier.

Therefore, when the first coupled signal and the second coupled signal are subjected to photoelectric conversion, since one polarization state has an optical carrier and the other polarization state does not have an optical carrier, the signal power obtained by mixing the polarization state signal of the optical carrier is obtained. To be larger than the polarization state signal without the optical carrier, the signal energy without the optical carrier is small, and can be treated as a noise signal. Therefore, the data signal loaded in the polarization state signal having the optical carrier can be recovered therefrom by photoelectric conversion. For the first coupled signal, the first data signal loaded by the first polarization state signal can be demodulated, and for the second coupled signal, the second data signal loaded by the second polarization state can be demodulated.

The first photoelectric conversion module and the second photoelectric conversion module may specifically be photoelectric converters.

The second optical coupling module and the third optical coupling module may specifically be photocouplers.

The first optical shunt module can be an optical splitter. The second optical shunt module can also be an optical splitter, or can be implemented in other ways. The third carrier separation module may have multiple implementation manners. In a possible implementation manner, refer to FIG. 9, which is a schematic structural diagram of a third carrier separation module of the optical signal receiver in the embodiment of the present application. The third carrier separation module 801 can include an optical circulator 811 and a carrier optical filter 821.

The first port of the optical circulator 811 receives the optical polarization multiplexing signal, the second port is connected to the first port of the carrier optical filter 821, and the third port is connected to the first optical branching module 802; The second port of the optical filter is connected to the second optical branching module 803; The optical polarization multiplexed signal is output to the carrier optical filter 821 via the second port of the optical circulator 811; the optical carrier is filtered out by the carrier optical filter 821, and the filtered optical carrier is output to the The second optical branching module 803 reflects the optical signal of the filtered optical carrier back to the optical circulator 811, and outputs the optical port 811 to the first optical branching module 802 through the third port.

At this time, the third port of the optical circulator 811 is the first output end of the third carrier separation module, and the second port of the carrier optical filter is the second output end of the third carrier separation module.

Of course, as another possible implementation manner, the third carrier separation module further comprises an optical circulator and a signal optical carrier. At this time, the first port of the optical circulator receives the optical polarization multiplexed signal, and the second port connects the signal light. The first port of the filter is connected to the second optical branching module; the second port of the signal optical filter is connected to the first optical branching module. The optical polarization multiplexed signal is output to the signal optical filter through the second port of the optical circulator; the optical carrier is filtered by the signal optical filter, and the filtered optical carrier is reflected back to the optical circulator, and the optical circulator is passed through the optical circulator The third port output outputs the optical signal filtered out of the optical carrier from the second port to the first optical branching module. In this case, the third port of the optical circulator is the second output of the third carrier separation module, and the second port of the carrier optical filter is the first output of the third carrier separation module. In order to improve the demodulation accuracy and improve the sensitivity, the second optical branching module may further adjust the power of the first optical carrier and the second optical carrier, so that the optical carrier and the optical signal in the coupled coupled signal have A certain power ratio, so that the data signal can be accurately demodulated. Therefore, as a possible implementation, referring to FIG. 10, a schematic structural diagram of a second optical branching module in the optical signal receiver of the embodiment of the present application is shown.

The second optical branching module 803 can include an optical splitter 813, a first power control module 823, and a second power control module 833.

The input end of the optical splitter 813 is connected to the third carrier separation module 801. The first output terminal is connected to the input end of the first power control module 823, and the second output terminal is connected to the input end of the second power control module 833.

The output of the first power control module 823 is connected to the second optical coupling module 805; the second power control module 833 is connected to the 90-degree polarization rotation module 804.

The optical carrier separated by the third carrier separation module 801 is divided into a first optical carrier and a second optical carrier by the optical splitter 813, and the first optical carrier passes through the first power control module. 823 After the power is adjusted, the second optical carrier is adjusted by the second power control module 833 and output.

The first power control module and the second power control module may specifically be a tunable optical attenuator, and the adjusted power is greater than the sensitivity of the optical signal receiver. Of course, in order to further improve the accuracy, the optical signal receiver may further include an optical amplifier and a narrowband optical filter. The optical carrier separated by the third carrier separation module is first amplified by the optical amplifier, and then filtered by the narrowband optical filter to filter out the noise of the optical amplifier. After that, it enters the second optical branching module. That is, the second output end of the third carrier separation module sequentially passes through the optical amplifier and the narrowband optical filter and is connected to the input end of the second optical branching module. The optical signal receiver of Figs. 8 to 10 can demodulate the optical polarization multiplexed signal generated by the optical signal transmitter described in any of the above embodiments. Moreover, the optical signal receiver of the embodiment of the present application has a simple structure and low complexity. FIG. 11 is a schematic structural diagram of another embodiment of an optical signal receiver according to an embodiment of the present application, where the optical signal receiver may include:

The third optical branching module 1101, the third photoelectric conversion module 1102, the fourth carrier separation module 1103, the 90-degree polarization rotation module 1104, the fourth optical coupling module 1105, and the fourth photoelectric conversion module 1106.

The first output end of the third optical branching module 1101 is connected to the third photoelectric conversion module 1102, and the second output end is connected to the fourth carrier separation module 1103.

The first output of the fourth carrier separation module 1103 is coupled to the 90 degree polarization rotation module 1104.

The input ends of the fourth optical coupling module 1105 are respectively connected to the 90-degree polarization rotation module 1104 and the third optical branch module 1101 second output end.

The input end of the fourth photoelectric conversion module 1106 is connected to the output end of the fourth optical coupling module 1105.

The optical polarization multiplexing signal is divided into a first optical polarization multiplexing signal and a second optical polarization multiplexing signal by the third optical branching module 1101, wherein the optical polarization multiplexing signal is orthogonal to the polarization state. a first polarization state signal and a second polarization state signal having no optical carrier; the first polarization state signal is loaded with the first data signal, and the second polarization state signal is loaded with the second data signal; The first optical polarization multiplexing signal is demodulated by the third photoelectric conversion module 1102 by a first data signal;

The second optical polarization multiplexing signal is separated by the fourth carrier separation module 1103 by an optical carrier and an optical signal that does not include an optical carrier; the optical carrier is deflected by the 90-degree polarization rotation module 1104 and then passes through the fourth light. The coupling module 1105 is coupled to the optical signal, and outputs the coupled signal to the fourth photoelectric conversion module 1106 to demodulate the second data signal.

The second polarization state signal of the first polarization multiplexing signal does not have an optical carrier, and the first polarization state signal has an optical carrier. Therefore, the signal power obtained by mixing the first polarization state signal by the third photoelectric conversion module is greater than that without the light. The second polarization state signal of the carrier has a small energy of the second polarization state signal without the optical carrier, and can be treated as a noise signal. Therefore, the first polarization state signal having the optical carrier can be recovered from the photoelectric conversion. A data signal.

The second polarization multiplexed signal is formed into a coupled signal by carrier separation, optical carrier conversion, and optical coupling, such that the first polarization state signal does not have an optical carrier, and the second polarization state signal has an optical carrier, and thus the second polarization state signal The signal power obtained by mixing the fourth photoelectric conversion module is greater than the first polarization state signal without the optical carrier, and the energy of the first polarization state signal without the optical carrier is small, and can be treated as a noise signal, and therefore, photoelectrically converted. The second data signal loaded in the second polarization state signal having the optical carrier can be recovered therefrom.

The third optical branching module is specifically an optical splitter, and the optical signals can be divided into the same two paths.

The third photoelectric conversion module and the fourth photoelectric conversion module may specifically be photoelectric converters.

The fourth optical coupling module may specifically be a photocoupler. The fourth carrier separation module may have multiple implementation manners. In a possible implementation manner, referring to FIG. 12, it is a schematic structural diagram of a fourth carrier separation module of the optical signal receiver in the embodiment of the present application. The fourth carrier separation module 1103 can include an optical circulator 1113 and a carrier optical filter 1123.

The first port of the optical circulator 1103 is connected to the second output end of the third optical branching module 1101, the second port is connected to the first port of the carrier optical filter 1123, and the third port is connected to the fourth optical coupling. Module 1105; the second port of the carrier optical filter 1123 is connected to the 90-degree polarization rotation module 1104.

The second optical polarization multiplexing signal outputted by the second output end of the third branching module is output to the carrier optical filter 1123 via the optical circulator 1113; the carrier optical filter 1123 outputs the filtered optical carrier To the 90-degree polarization rotation module 1104, the optical signal of the filtered optical carrier is reflected back to the optical circulator 1113; and the third port of the optical circulator 1113 is output to the fourth optical coupling module 1105. In this case, the third port of the optical circulator 1113 is the second output of the fourth carrier separation module, and the second port of the carrier optical filter 1123 is the first output of the fourth carrier separation module. Of course, as another possible implementation manner, the fourth carrier separation module further comprises an optical circulator and a signal optical carrier. In this case, the first port of the optical circulator is connected to the third optical branch module, and the second port is connected to the signal. The first port of the optical filter, the third port is connected to the 90-degree polarization rotation module; the second port of the signal optical filter is connected to the fourth optical coupling module. The second optical polarization multiplexed signal is output to the signal optical filter through the second port of the optical circulator; the optical carrier is filtered by the signal optical filter, and the filtered light is carried back to the optical circulator through the optical ring. The third port of the device is output to the 90-degree polarization rotation module, and the optical signal filtered out of the optical carrier is output to the fourth optical coupling module. In this case, the third port of the optical circulator is the first output of the fourth carrier separation module, and the second port of the signal optical filter is the second output of the fourth carrier separation module. The optical signal receiver illustrated in Figures 11 through 12 can demodulate the optical polarization multiplexed signal generated by the optical signal transmitter described in any of the above embodiments. The optical carrier and the optical signal, which are particularly suitable for the first polarization state signal, have an optical polarization multiplexed signal with a preset power ratio, that is, an optical signal transmitter including a carrier signal power ratio control module, thereby improving the accuracy of demodulation. The optical signal transmitter of any one of the foregoing embodiments or the optical signal receiver of any of the embodiments may be applied to a terminal of a passive optical network system, where the terminal may be an OLT (Optical Line Terminal) or ONU (Optical Network Unit). The terminal includes the optical signal transmitter of any one of the above embodiments, which can implement the generation of the optical polarization multiplexed signal, and transmit the optical polarization multiplexed signal to implement data transmission. The optical signal receiver according to any of the foregoing embodiments is included. Demodulation of the optical polarization multiplexed signal generated by the optical signal transmitter described in any of the above embodiments may be implemented, The data signal is demodulated therefrom.

Therefore, the embodiment of the present application further provides an optical line terminal, including the optical signal transmitter according to any of the above embodiments, and/or the optical signal receiver described in any of the embodiments.

The embodiment of the present application further provides an optical network unit, including the optical signal transmitter of any of the above embodiments and/or the optical signal receiver of any of the embodiments.

By setting the optical line terminal or optical network unit of the optical signal transmitter and the optical signal receiver, large-capacity optical fiber communication can be realized to improve communication quality and communication efficiency.

The embodiment of the present application further provides a passive optical network system, where the passive optical network system includes a light path terminal and an optical network unit. The optical line terminal may include the optical signal transmitter according to any of the above embodiments and/or the optical signal receiver described in any of the embodiments; the optical network unit may include any one of the foregoing embodiments. Optical signal transmitter and/or optical signal receiver as described in any of the embodiments. The passive optical network system provided by the embodiment of the present application can realize large-capacity optical fiber communication, and can improve communication quality and communication efficiency. FIG. 13 is a flowchart of an embodiment of an optical signal modulation method according to an embodiment of the present application. The optical signal modulation method may be specifically applied to an optical signal transmitter according to any of the foregoing embodiments. The method can include the following steps:

1301: The polarized light output from the light source is divided into first polarized light and second polarized light whose polarization states are orthogonal.

1302: modulate the first polarization state light to a first data signal to generate a first polarization state signal. After the first polarization state modulates the first data signal, the optical carrier and the optical signal may be adjusted to a preset power ratio, and finally the first polarization state signal having an optical carrier and the optical signal having a certain power ratio is finally generated.

1303: modulate the second polarization state light to a second data signal, and suppress the optical carrier to generate a second polarization state signal.

1304: Integrate the first polarization signal and the second polarization signal into a polarization polarization multiplexing signal orthogonal to a polarization state.

In this embodiment, the polarized light output by the light source is divided into a first polarization state and a second polarization state in which the polarization states are orthogonal, and the first polarization state light modulates the first data signal, and the second polarization state light modulation Two data signals and suppressing their optical carriers, thereby generating a first polarization state signal with an optical carrier and no optical load The second polarization state signal of the wave combines the first polarization state signal and the second polarization state signal to form a polarization polarization multiplexed signal of orthogonal polarization states, thereby carrying two data signals through one optical polarization multiplexing signal, increasing The amount of data transmitted by the communication increases the system capacity.

The optical polarization multiplexed signal includes a first polarization state signal and a second polarization state signal whose polarization states are orthogonal, and the second polarization state signal is an optical signal that does not have an optical carrier. When performing optical signal demodulation, the first polarization The energy of the state signal is greater than the energy of the signal of the second polarization state, and after the power adjustment by the carrier signal ratio control module, the energy of the first polarization state signal is much larger than the energy of the second polarization state signal, so that the second The polarization state signal is processed as a noise signal, so that the first data signal modulated by the first polarization state signal can be recovered. For the second polarization state signal, the optical carrier is rotated by the optical carrier, so that the second polarization state signal is an optical signal having an optical carrier, and the first polarization state signal is an optical signal having no optical carrier, and the second polarization state can also be demodulated. The second data signal modulated in the polarization signal is simple and efficient. FIG. 14 is a flowchart of an embodiment of an optical signal demodulation method according to an embodiment of the present disclosure. The optical signal demodulation method may be specifically applied to the optical signal demodulation machine described in any of the foregoing embodiments. The method can include the following steps:

1401: Separating the received optical polarization multiplexed signal into an optical carrier and an optical signal that does not include an optical carrier.

The optical polarization multiplexing signal is composed of a first polarization state signal orthogonal to the polarization state and a second polarization state signal having no optical carrier. The first polarization state signal is loaded with the first data signal, and the second polarization state is A second data signal is loaded in the signal.

1402: Divide the optical carrier into a first optical carrier and a second optical carrier, and divide the optical signal into a first optical signal and a second optical signal.

The dividing the optical carrier into the first optical carrier and the second optical carrier may be specifically: dividing the optical carrier into the first optical carrier and the second optical carrier, and respectively respectively, respectively, the first optical carrier and the second optical carrier. The path optical carrier performs power adjustment to improve the accuracy of demodulation.

The optical carrier may also be first amplified by an optical amplifier and filtered out the noise of the optical amplifier, and then divided into a first optical carrier and a second optical carrier.

1403: coupling the first optical signal to the first optical carrier as a first coupled signal, and The second optical signal is coupled to the second optical carrier that is deflected at 90 degrees into a second coupled signal. Wherein, the generated first coupled signal and the second coupled signal both include a first polarization state signal and a second polarization state signal whose polarization states are orthogonal.

1404: The first coupled signal is photoelectrically converted to demodulate the first data signal.

1405: The second coupled signal is photoelectrically converted to demodulate the second data signal.

In this embodiment, by separating the optical polarization multiplexing signal, the separated optical carrier and the optical signal are equally divided into two paths, and the first optical carrier and the first optical signal can be directly coupled, and the second path is The optical carrier is first deflected by 90 degrees and then coupled with the second optical signal, so that the first polarization signal in the first coupled signal has an optical carrier, the second polarization signal does not have an optical carrier, and the second coupled signal A polarization state signal does not have an optical carrier, and the second polarization state signal has an optical carrier. Therefore, when the first coupled signal and the second coupled signal are subjected to photoelectric conversion, the polarization state signal without the optical carrier can be treated as noise, thereby demodulating the first data signal and the second coupled signal in the first coupled signal. The second data signal realizes demodulation of the optical polarization multiplexed signal. FIG. 15 is a flowchart of an embodiment of an optical signal demodulation method according to an embodiment of the present application. The optical signal demodulation method may be specifically applied to the optical signal demodulation machine described in any of the foregoing embodiments. The method can include the following steps:

1501 divides the optical polarization multiplexed signal into the same first polarization multiplexed signal and second polarization multiplexed signal.

The optical polarization multiplexed signal is composed of a first polarization state signal orthogonal to the polarization state and a second polarization state signal having no photocarrier wave. A first data signal is loaded in the first polarization state signal, and a second data signal is loaded in the second polarization state signal.

1502: Perform photoelectric conversion on the first polarization multiplexed signal to demodulate the first data signal. 1503: Separating the second polarization multiplexed signal into an optical carrier and an optical signal that does not include an optical carrier.

1504: The optical carrier is coupled to the optical signal after being deflected by 90 degrees, and photoelectrically converts the coupled signal to demodulate the second data signal.

Wherein, the optical carrier can be adjusted by the optical amplifier and then rotated by 90 degrees. And improve the demodulation accuracy.

In this embodiment, the optical polarization multiplexing signal is divided into two paths, the first optical polarization multiplexing signal is directly subjected to photoelectric conversion, and the second optical polarization multiplexing signal is first separated from the optical carrier and the optical signal, and the optical carrier is performed. After being deflected by 90 degrees, it is coupled with the optical signal, and then photoelectrically converted, so that the first polarization state signal of the first optical polarization multiplexing signal has an optical carrier, and the second polarization state signal does not have an optical carrier, and the coupling generates a signal. A polarization state signal does not have an optical carrier, and the second polarization state signal has an optical carrier. Therefore, when performing photoelectric conversion, the polarization state signal without the optical carrier can be treated as noise, thereby demodulating the first data signal in the first coupled signal and the second data signal in the second coupled signal, thereby realizing light polarization. Demodulation of the multiplexed signal.

For the foregoing method embodiments, for the sake of brevity, they are all described as a series of action combinations, but those skilled in the art should understand that the present application is not limited by the described action sequence, because according to the present application, Some steps can be performed in other orders or at the same time. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the operations and modules involved are not necessarily required by the present application.

The various embodiments in the present specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and the same similar parts between the various embodiments may be referred to each other. In the end, it should also be noted that, in this context, relational terms such as first and second are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these There is any such actual relationship or order between entities or operations. Furthermore, the terms "comprising," "comprising," or "includes" or "includes" are intended to include a non-exclusive inclusion, such that a process, method, article, or device that includes a plurality of elements includes not only those elements but also Other elements, or elements that are inherent to such a process, method, item, or device. An element defined by the phrase "comprising a singular" does not exclude the presence of additional singular elements in the process, method, item, or device that comprises the element.

The above description of the disclosed embodiments enables those skilled in the art to make or use the application. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to the embodiments shown herein, but the broadest scope consistent with the principles and novel features disclosed herein.

+

Claims

Rights request

1. An optical signal transmitter, characterized in that it includes a polarization beam splitter, a first modulation module, a second modulation module and a polarization combiner;

The output end of the polarization beam splitter is respectively connected to the input end of the first modulation module and the input end of the second modulation module; the output end of the first modulation module and the output end of the second modulation module are respectively connected to the polarization beam splitter. Combiner input;

The polarized light output by the light source is divided into first polarized light and second polarized light with orthogonal polarization states through the polarization beam splitter; the first polarized light modulates the first data signal through the first modulation module , generate a first polarization signal; the second polarization light modulates the second data signal through the second modulation module, and suppresses the optical carrier, generating a second polarization signal; the first polarization signal and the The second polarization signal is synthesized into an optical polarization multiplexing signal through the polarization combiner.

2. The transmitter according to claim 1, wherein the first modulation module includes a first modulator and a carrier signal power ratio control module;

The input end of the first modulator is connected to the output end of the polarization beam splitter; the output end of the first modulator is connected to the input end of the carrier signal power ratio control module; the output end of the carrier signal power ratio control module is connected to The input terminal of the polarization combiner;

After the first polarized light modulates the first data signal by the first modulator, it is output to the carrier signal power ratio control module, and the carrier signal power ratio control module adjusts the optical carrier and the signal excluding the optical carrier. After the optical signal has a preset power ratio, a first polarization signal is formed.

3. The transmitter according to claim 1 or 2, characterized in that the second modulation module includes a second modulator and a first carrier separation module;

The input end of the second modulator is connected to the output end of the polarization beam splitter; the output end of the second modulator is connected to the input end of the first carrier separation module; the output end of the first carrier separation module is connected to the polarization beam splitter. Combiner input;

After the second polarized light modulates the second data signal through the second modulator, the optical carrier is separated by the first carrier separation module, and the second polarized signal formed after the separated optical carrier is output to the Polarization combiner.

4. The transmitter according to claim 1 or 2, characterized in that, the second modulation module Includes splitters, delays and Mach-Zehnder modulators MZM;

The first output end of the splitter is connected to the input end of the retarder; the MZM input end is connected to the second output end of the splitter, the retarder output end, and the output end of the polarization beam splitter respectively. ; The MZM output terminal is connected to the polarization combiner;

The second data signal is divided into a first signal and a second signal through the splitter; the first signal is output to the MZM modulator; the first signal is output after being delayed by the delayer to the MZM modulator, the MZM modulator and the second polarized light are modulated to generate a second polarized signal.

5. The transmitter according to any one of claims 2 to 4, characterized in that the carrier signal control ratio module includes a second carrier separation module, an optical amplifier and a first optical coupling module;

The input end of the second carrier separation module is connected to the output end of the first modulator; the first output end of the second carrier separation module is connected to the input end of the optical amplifier; the input end of the first optical coupling module is connected to the input end of the optical amplifier respectively. The second output end of the second carrier separation module is connected to the output end of the optical amplifier;

After the first polarized light modulates the first data signal through the first modulator, it is output to the second carrier separation module, and the filtered optical carrier is output to the optical carrier through the second carrier separation module. Amplifier, output the optical signal of the filtered optical carrier to the first optical coupling module; couple the optical signal of the filtered optical carrier and the optical carrier passing through the optical amplifier to have a preset power ratio through the first optical coupling module the first polarization signal.

6. An optical signal receiver, characterized in that it includes a third carrier separation module, a first optical splitting module, a second optical splitting module, a 90-degree polarization rotation module, a second optical coupling module, and a third optical coupling module. Module, first photoelectric conversion module and second photoelectric conversion module:

The first output end of the third carrier separation module is connected to the input end of the first optical splitting module; the second output end of the third carrier separation module is connected to the input end of the second optical splitting module; the second The first output end of the optical splitting module is connected to the 90-degree polarization rotation module; the input end of the second optical coupling module is connected to the first output end of the first optical splitting module and the second optical splitting module respectively. two output terminals; the input terminal of the third optical coupling module is respectively connected to the second output terminal of the first optical splitting module and the output terminal of the 90-degree polarization rotation module; the input terminal of the first photoelectric conversion module is connected to the The output end of the second optical coupling module; the input end of the second photoelectric conversion module is connected to the output end of the third optical coupling module. come out;

The optical polarization multiplexing signal separates the optical carrier and the optical signal excluding the optical carrier through the third carrier separation module; the optical signal is divided into a first optical signal and a second optical signal through the first optical splitting module. ; The optical carrier is divided into a first optical carrier and a second optical carrier through the second optical splitting module; wherein the optical polarization multiplexing signal consists of a first polarization signal with orthogonal polarization states and a non-parallel polarization signal. Composed of a second polarization state signal with an optical carrier;

The first optical carrier and the first optical signal are coupled into a first coupling signal through the second optical coupling module; the second optical carrier is rotated by the 90-degree polarization rotation module and coupled to the first optical signal. The second optical signal is coupled into a second coupling signal through the third optical coupling module;

The first coupled signal is demodulated by the first photoelectric conversion module to obtain a first data signal; the second coupled signal is demodulated by the second photoelectric conversion module to obtain a second data signal.

7. The receiver according to claim 6, wherein the third carrier separation module includes an optical circulator and a carrier optical filter;

The first port of the optical circulator receives the optical polarization multiplexing signal, the second port is connected to the first port of the carrier optical filter, and the third port is connected to the first optical splitting module; the carrier optical filter The second port is connected to the second optical splitting module;

The optical polarization multiplexing signal is output to the carrier optical filter through the second port of the optical circulator; the optical carrier is filtered out through the carrier optical filter, and the filtered optical carrier is output to the second optical filter The splitting module reflects the optical signal filtered out of the optical carrier back to the optical circulator, and outputs it to the first optical splitting module through the third port of the optical circulator.

8. The receiver according to claim 6 or 7, characterized in that the second optical splitter module includes an optical splitter, a first power control module and a second power control module:

The input end of the optical splitter is connected to the second output end of the third carrier separation module; the first output end of the optical splitter is connected to the input end of the first power control module; the second output end of the optical splitter is connected to the input end of the first power control module. The output end is connected to the input end of the first power control module; the output end of the first power control module is connected to the input end of the second optical coupling module; the output end of the second power control module is connected to the third optical coupling module input terminal;

The optical carrier separated by the third carrier separation module is divided into a first optical path through the optical splitter. carrier and a second optical carrier, the first optical carrier is output after adjusting the power by the first power control module, and the second optical carrier is output after adjusting the power by the second power control module.

9. An optical signal receiver, characterized in that it includes a third optical splitting module, a third photoelectric conversion module, a fourth carrier separation module, a 90-degree polarization rotation module, a fourth optical coupling module and a fourth photoelectric conversion module ;

The first output end of the third optical splitting module is connected to the input end of the third photoelectric conversion module; the second output end of the third optical splitting module is connected to the input end of the fourth carrier separation module; the fourth The first output end of the carrier separation module is connected to the input end of the 90-degree polarization rotation module; the input end of the fourth optical coupling module is connected to the second output end of the fourth carrier separation module and the output end of the 90-degree polarization rotation module respectively. ;

The optical polarization multiplexing signal is divided into a first optical polarization multiplexing signal and a second optical polarization multiplexing signal through the third optical splitting module, wherein the optical polarization multiplexing signal is composed of a third optical polarization multiplexing signal with orthogonal polarization states. Composed of a polarization state signal and a second polarization state signal without an optical carrier;

The first optical polarization multiplexing signal is demodulated by the third photoelectric conversion module to obtain a first data signal;

The second optical polarization multiplexing signal separates the optical carrier and the optical signal excluding the optical carrier through the fourth carrier separation module; the optical carrier is deflected by the 90-degree polarization rotation module and then passes through the fourth optical coupling module. It is coupled with the optical signal, and the coupled signal is output to the fourth photoelectric conversion module to demodulate the second data signal.

10. The receiver according to claim 9, wherein the fourth carrier separation module includes an optical circulator and a carrier optical filter;

The first port of the optical circulator is connected to the second output end of the third optical splitting module, the second port is connected to the first port of the carrier optical filter, and the third port is connected to the fourth optical coupling module; The second port of the carrier optical filter is connected to the 90-degree polarization rotation module;

The second optical polarization multiplexing signal is output to the carrier optical filter through the second end of the optical circulator; the carrier optical filter outputs the filtered optical carrier to the 90-degree polarization rotation module, The optical signal filtered out of the optical carrier is reflected back to the optical circulator; and output to the fourth optical coupling module through the third port of the optical circulator.

11. An optical line terminal, characterized by comprising an optical signal transmitter according to any one of claims 1 to 5 and/or an optical signal receiver according to any one of claims 6 to 10.

12. An optical network unit, characterized in that it includes an optical signal transmitter according to any one of claims 1 to 5 and/or an optical signal receiver according to any one of claims 6 to 10.

13. A passive optical network system, characterized by comprising the optical line terminal as claimed in claim 11 and the optical network unit as claimed in claim 12.

14. An optical signal modulation method, characterized by including:

Divide the polarized light output from the light source into a first polarized light and a second polarized light with orthogonal polarization states; modulate the first polarized light into a first data signal to generate a first polarized signal; convert the second polarized light into a first polarized light. The polarized light modulates the second data signal and suppresses the optical carrier to generate the second polarized signal;

The first polarization signal and the second polarization signal are synthesized into an optical polarization multiplexing signal with orthogonal polarization states.

15. The method according to claim 14, characterized in that, the first polarization state light is modulated into the first data signal to generate a first polarization state signal;

The first polarization state light is modulated into the first data signal, and the optical carrier and the optical signal are adjusted to a preset power ratio to generate the first polarization state signal.

16. An optical signal demodulation method, characterized by including:

Separating the received optical polarization multiplexed signal into an optical carrier and an optical signal excluding the optical carrier, wherein the optical polarization multiplex signal consists of a first polarization state signal with orthogonal polarization states and a second polarization state without an optical carrier. Signal composition;

Divide the optical carrier into a first optical carrier and a second optical carrier, and divide the optical signal into a first optical signal and a second optical signal;

Coupling the first optical signal and the first optical carrier into a first coupling signal, and coupling the second optical signal and the second optical carrier deflected by 90 degrees into a second coupling signal;

The first coupled signal is subjected to photoelectric conversion to demodulate the first data signal;

The second coupled signal is subjected to photoelectric conversion to demodulate the second data signal.

17. An optical signal demodulation method, characterized by including:

The optical polarization multiplexing signal is divided into the same first polarization multiplexing signal and a second polarization multiplexing signal, wherein the optical polarization multiplexing signal consists of a first polarization state signal with orthogonal polarization states and a first polarization state signal without an optical carrier. Second polarization signal composition;

The first polarization multiplexing signal is subjected to photoelectric conversion to demodulate a first data signal; the second polarization multiplexing signal is separated into an optical carrier and an optical signal excluding the optical carrier; the optical carrier is polarized at 90 degrees Then, it is coupled with the optical signal, and the coupled signal is photoelectrically converted to demodulate the second data signal.