WO2018176590A1

WO2018176590A1 - Device and method for performing safety protection on optical signal to be transmitted in wdm system

Info

Publication number: WO2018176590A1
Application number: PCT/CN2017/084240
Authority: WO
Inventors: 王可; 张晗; 吉建华; 徐铭; 杨淑雯
Original assignee: 深圳大学
Priority date: 2017-03-31
Filing date: 2017-05-12
Publication date: 2018-10-04
Also published as: CN107017951B; CN107017951A

Abstract

The present invention relates to a device for performing safety protection on an optical signal to be transmitted in a WDM system. The device comprises: a transmitting and encoding unit used for performing optical wave decomposition on a WDM optical signal and multiplexing same into N optical signals with a single wavelength, performing optical encoding on the obtained optical signals, and combining the N signals subjected to optical encoding into one WDM optical encoding signal and transmitting the WDM optical encoding signal to a transmission optical fiber; a receiving and decoding unit used for receiving the WDM optical encoding signal, converting the WDM optical encoding signal into an optical signal of the WDM system, and transmitting the optical signal to an optical receiver of the WDM system; and a codeword control unit used for generating control codewords and separately transmitting the codewords to the transmitting and encoding unit and the receiving and decoding unit. The present invention also relates to a method for performing safety protection on an optical signal to be transmitted in a WDM system. The device and method for performing safety protection on an optical signal to be transmitted in a WDM system provided by the present invention have the following beneficial effects: it is difficult to illegally steal the optical signal to be transmitted, and the transmission of the signal is safe.

Description

Title: Apparatus and method for security protection of transmitted optical signals in a WDM system

Technical field

[0001] The present invention relates to the field of signal transmission, and more particularly to an apparatus and method for securely protecting transmitted optical signals in a WDM system.

Background technique

[0002] The existing WDM optical fiber communication system is composed of a WDM optical transmitter, a WDM optical receiver, and an optical fiber, as shown in FIG. An optical transmitter (1-N) containing N user signals in a WDM optical transmitter forms N conventional single-wavelength optical fiber communication systems, and combines N multiple channels into one optical wave division by a wavelength division multiplexer. Signal output, transmitted to the far end via fiber optics. After receiving the optical wavelength division multiplexing signal, the remote WDM receiver separates N single-wavelength channels by the wave decomposition multiplexer, and each channel is processed by the optical receiver to obtain N user information. Existing WDM fiber-optic communication systems have potential safety hazards that can be eavesdropped. Because conventional single-wavelength fiber-optic communication systems operate in the OOK system, energy detectors can be used to obtain user information transmitted on the fiber. Multiple user information is transmitted in the WDM system, which improves system security. But when the eavesdropper uses a spectrum analyzer to strip a channel from the WDM channel, the user information is still available, so the WDM fiber-optic communication system is still insecure.

technical problem

[0003] Type a paragraph describing the technical problem here.

Problem solution

Technical solution

[0004] The technical problem to be solved by the present invention is to provide a kind of transmission optical signal in a WDM system that is difficult to be illegally stolen and secure, which is easy to be illegally stolen and insecure in the prior art. Apparatus and method for performing safety protection.

[0005] The technical solution adopted by the present invention to solve the technical problem is: constructing a device for performing security protection on a transmitted optical signal in a WDM system, including: [0006] The transmitting coding unit is connected between the optical transmitter of the WDM and the transmission fiber, and optically demultiplexes the WDM optical signal into N single-wavelength optical signals, optically codes the obtained optical signals, and Combining the N channels of the optically encoded signals into a WDM optical coded signal, and transmitting the WDM optical coded signal to the transmission fiber; wherein, the carrier wavelength of the coded optical carrier of each channel is different;

[0007]

Receiving a decoding unit: receiving the WDM optical coded signal, converting the WDM optical coded signal into an optical signal of the WD M system, and transmitting the optical signal to the optical receiver of the WDM system;

[0008] a codeword control unit: generating a control codeword and transmitting to the transmit coding unit and the receive decoding unit, respectively, wherein the control codeword is used to control parameters of the coded optical carrier of each channel to generate different, corresponding to The coded optical carrier of each channel or control outputs a decoded optical carrier signal of each channel.

[0009] Further, the coded optical carriers of each channel respectively comprise a plurality of set inter-turn units arranged in sequence, and the wavelength of light in each set inter-turn unit is different from that in the adjacent set inter-turn unit The wavelength of light; the wavelength of the light in the same number of the coded optical carrier of each channel is different.

[0010] Further, the transmit coding unit further includes a wave decomposition multiplexer, a plurality of light receiving modules, a plurality of light modulation modules, a light source, and a transmit wavelength division multiplexer; the wave decomposition multiplexer includes a An input terminal and a plurality of output terminals connected to an optical transmitter output of the WDM system, wherein the plurality of output ends of the wave decomposition multiplexer are respectively connected to an input end of a light receiving module, and a light receiving module The output end is connected to a modulation signal input end of a light modulation module; the light source comprises a plurality of coded optical carrier signal output ends, and an input end of an optical modulation module is connected to a coded optical carrier signal output end; an output end of the optical modulation module Connected to an input end of the transmitting wavelength division multiplexer, the output end of the transmitting wavelength division multiplexer is connected to a transmission fiber; the number of output terminals of the wave decomposition multiplexer, the number of optical receiving modules, and light The number of modulation modules, the number of encoded optical carrier outputs, and the number of inputs of the transmit wavelength division multiplexing module are equal

[0011] Further, the light source comprises a broad spectrum light source and an emission wavelength selection switch, the emission wavelength selection switch comprises an input end, a control end and a plurality of output ends; the wide spectrum light source generates a broad spectrum optical signal And outputting to the input end of the transmit wavelength selection switch, the control end of the transmit wavelength selection switch receives the transmit control codeword generated by the codeword control unit as a code conversion control signal, so that the transmit wavelength is selected The plurality of output ends are respectively obtained from the optical signals input by the wide-spectrum light source and respectively outputted in accordance with the The encoded optical carrier signal required to control the codeword is described.

[0012] Further, the receiving and decoding unit includes a receiving wavelength selection switch, a plurality of optical narrow pulse receiving modules, and a receiving wavelength division multiplexer; the receiving wavelength selection switch includes an input end, a control end, and a plurality of output ends; the input end of the receiving wavelength selection switch is connected to the transmission fiber, and the control end of the receiving wavelength selection switch receives the receiving control code word generated by the code word control unit as a control signal, so that The plurality of output ends of the receiving wavelength selection switch respectively output the modulated coded optical carrier signals output by the optical modulation modules of the transmit coding unit; the plurality of output ends of the receive wavelength selection switches are respectively connected to An input end of the plurality of narrow pulse receiving modules, an output end of an optical narrow pulse receiving module is respectively connected to an input end of the receiving wavelength division multiplexer, and an output end of the receiving wavelength division multiplexer The optical receiver connection of the WDM system.

[0013] Further, the optical narrow pulse receiving module detects the modulated encoded optical carrier signal received by the optical narrow pulse receiving module, obtains a modulated optical signal, and outputs the modulated optical signal to a corresponding input port of the receiving wavelength division multiplexer. .

[0014] Further, the control codeword includes a transmit control codeword and a receive control codeword, and the transmit control codeword and the receive control codeword are respectively sent to the transmit coding unit and the The receiving decoding unit is described.

[0015] The present invention also relates to a method for security protection of an optical signal transmitted in a WDM system, comprising: after the WDM system outputs the multiplexed optical signal, the optical signal is processed as follows:

[0016] Decomposing and optically converting the optical signal of the WDM according to the channel, N-channel optical signals of a single wavelength, optically encoding the obtained optical signals, and multiplexing the encoded optical carriers modulated by the respective channels to obtain WDM optical coding. And transmitting the WDM optical code to the transmission fiber; wherein, the carrier wavelength of the coded optical carrier of each channel is different;

[0017] After the WDM system receives the optical signal transmitted on the transmission fiber after the processing, the optical signal is processed as follows:

Receiving the WDM optical code, demultiplexing the WDM optical code into a modulated coded optical carrier signal of each channel, and performing demodulation to obtain a user optical signal of each channel, and obtaining the obtained channel The user optical signal is multiplexed into an optical signal of the WDM and transmitted to the optical receiver of the WDM system;

[0019] wherein a control codeword is generated and used for the optical signal processing described above, wherein the control codeword is used to control parameters of the coded optical carrier of each channel to generate different coded optical carriers corresponding to each channel or Control The modulated, encoded optical carrier signals of different channels are output.

[0020] Further, the coded optical carriers of each channel respectively comprise a plurality of set inter-turn units arranged in sequence, and the wavelength of light in each set inter-turn unit is different from that in the adjacent set inter-turn unit The wavelength of light; the wavelength of the light in the same number of the coded optical carrier of each channel is different.

[0021] Further, the wavelength selection is controlled by controlling the codeword, so that each set wavelength component input to the wavelength selection signal is respectively output to the output end of the wavelength selection switch, thereby obtaining coded light. Carrier signal or modulated encoded optical carrier signal.

Advantageous effects of the invention

Beneficial effect

[0022] An apparatus and method for implementing security protection for transmitting optical signals in a WDM system embodying the present invention has the following beneficial effects: It is transmitted after processing an optical signal transmitted on an optical fiber in an existing WDM system. On the optical fiber, the carrier of a user signal changes in the optical signal transmitted on the optical fiber, and the law of variation is determined by the control codeword, so that even if the control codeword is not known, even for the optical fiber The optical signal on the interception intercepts the optical signal on the optical fiber, and it is impossible to completely demodulate the signal on one channel, so that it is impossible to obtain a user signal. Therefore, it is more difficult to be illegally stolen and the transmission of signals is safer.

Brief description of the drawing

DRAWINGS

1 is a schematic structural diagram of an apparatus and method for protecting a transmitted optical signal in a WDM system according to an embodiment of the present invention;

2 is a schematic structural view of a transmitting unit in the embodiment; [0024] FIG.

3 is a schematic structural diagram of a receiving unit in the embodiment;

4 is a schematic diagram of a first carrier wavelength conversion in one case in the embodiment;

[0027] FIG. 5 is a flow chart of a method for security protection of transmitted optical signals in a WDM system in the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

[0028] The description of the preferred embodiment of the invention is entered here. Embodiments of the invention

[0029] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0030] As shown in FIG. 1, in an embodiment of an apparatus and method for security protection of transmitted optical signals in a WDM system, for an existing WDM system, a light emitter and light in a WDM system The transmission fibers are directly connected between the receivers, and the optical signals transmitted on the transmission fibers are multiplexed signals in the WDM system. In FIG. 1, between the optical transmitter and the optical receiver of the WDM system, not only the transmission optical fiber but also the transmission coding unit, the reception decoding unit, and the codeword control unit, and the signal transmitted on the transmission optical fiber are included. Nor is it a conventional multiplexed signal, but a new multiplexed signal obtained by processing a conventional multiplexed signal. Even if this signal is illegally obtained, it cannot be decoded because it does not know the control codeword. Therefore, it is possible to protect the transmission content from leakage.

[0031] In this embodiment, as shown in FIG. 1, the transmission coding unit is connected between the optical transmitter of the WDM and the transmission fiber, and the WDM optical signal is optically demultiplexed into N optical signals of a single wavelength, The obtained optical signals are optically encoded, and the N optically encoded signals are combined into one WDM optical coded signal, and the WDM optical coded signal is transmitted to the transmission optical fiber; N is the WDM optical signal originally The number of channels, in other words, the WDM optical signal is usually obtained by multiplexing N signals; wherein the carrier wavelength of the coded optical carrier of each channel is different; and the input end of the receiving decoding unit and the above transmission fiber Connecting, receiving the WDM optical coded signal, converting the WDM optical coded signal into an optical signal of the WDM system, and transmitting the optical signal to the optical receiver of the WDM system; the codeword control unit is respectively connected to the above-mentioned transmit coding unit and the receive and decode unit, Generating a control codeword and transmitting to the transmit coding unit and the receive decoding unit, respectively, the control codeword being used to control the coded optical carrier of each channel Parameters to produce different corresponding to different encoded optical carrier wave or control of the output of each channel, the coded light modulated carrier signal of each channel. It is to be noted that, in this embodiment, the optical coding includes performing photoelectric conversion on the obtained channel optical signals of the WDM, and separately encoding and modulating optical carriers of the respective channels by using the obtained electrical signals, thereby obtaining each channel. The optical coded signal is obtained by multiplexing the obtained optical coded signals to obtain a WDM optical coded signal.

[0032] In this embodiment, the coded optical carriers of each channel respectively comprise a plurality of set inter-turn units arranged in sequence, and the wavelength of the light in each set of the inter-turn units is different from the adjacent set daytimes. The wavelength of light in the cell; each The wavelengths of the same sequence number of the coded optical carriers of the channels are different in the wavelength of the light in the inter-cell. In other words, in this embodiment, the multiplexed signal of the WDM system includes multiple channels (ie, multiple user signals, one channel for each user signal), and each channel corresponds to one coded optical carrier, each Although the coded optical carriers of the channel have the same structure, they are sequentially arranged by a plurality of set inter-turn units, but the wavelengths of each coded optical carrier are different, and, in a coded optical carrier, adjacent It is not the same to set the optical carrier in the day unit. The selection of the wavelength of the coded optical carrier and the change of the wavelength in the adjacent set of inter-turn cells are determined by the control codeword. When the control codeword is known, the information content carried by the modulated coded optical carrier can be obtained; and if the control codeword is not known, the first carrier in the current setting unit cannot be predicted. The wavelength does not know the wavelength of the coded optical carrier in the next setting unit, so the information content carried by the modulated coded optical carrier cannot be obtained.

[0033] In the present embodiment, the WDM optical transmitter outputs an optical multiplexed signal including optical signals output from a plurality of channels. In the above transmission coding unit, referring to FIG. 2, a wave decomposition multiplexer, a plurality of light receiving modules, a plurality of light modulation modules, a light source, and a transmission wavelength division multiplexer are included; the wave decomposition multiplexer includes a connection An input end of the optical transmitter output of the WDM system and a plurality of output terminals, wherein the plurality of output ends of the wave decomposition multiplexer are respectively connected to an input end of a light receiving module, and an output of a light receiving module The end is connected to the modulation signal input end of a light modulation module; the light source comprises a plurality of coded optical carrier signal output ends, and the input end of an optical modulation module is connected to a coded optical carrier signal output end; the output end of the optical modulation module is connected And at an input end of the transmitting wavelength division multiplexer, an output end of the transmitting wavelength division multiplexer is connected to a transmission fiber; an output terminal of the wave decomposition multiplexer, a number of optical receiving modules, and optical modulation The number of modules, the number of encoded optical carrier outputs, and the number of inputs of the transmitting wavelength division multiplexing module are equal. In this embodiment, the light source includes a broad spectrum light source and an emission wavelength selection switch, the emission wavelength selection switch includes an input end, a control end, and a plurality of output ends; the wide spectrum light source generates a broad spectrum optical signal and outputs the The transmitting wavelength selects an input end of the switch, and the control end of the transmit wavelength selection switch receives the transmit control codeword generated by the codeword control unit as a code conversion control signal, so that the transmit wavelength selects multiple outputs of the switch The ends are respectively obtained from the optical signals input by the wide-spectrum light source and respectively output encoded optical carrier signals that meet the requirements of the control codeword.

[0034] Generally speaking, in this embodiment, the signal processing for the transmitting end is a conventional WDM system. The multiplexed signal is demultiplexed, processed to obtain a signal on each channel, and then the user signals (one channel is transmitted by one user signal) on the obtained multiple channels are used as modulation signals to modulate the coded optical carrier corresponding to the channel. signal. That is, in this embodiment, there are a plurality of coded optical carrier signals, each coded optical carrier signal corresponds to one channel, and each coded optical carrier signal is on the same frame, and the carrier wavelength is different; For a coded optical carrier signal, the wavelength changes every other time during the setting of the inter-turn period; for the wavelength conversion of the encoded optical carrier signal, see Figure 4. An example in which the wavelengths of a plurality of coded optical carrier signals are converted along the inter-turn axis in one case in the present embodiment is shown in FIG.

3 is a schematic structural diagram of a receiving decoding unit in this embodiment. In this embodiment, the receiving decoding unit includes a receiving wavelength selection switch, a plurality of optical narrow pulse receiving modules, and a receiving wavelength division multiplexer; the receiving wavelength selection switch includes an input terminal, a control terminal, and a plurality of outputs. The receiving end of the receiving wavelength selection switch is connected to the transmission fiber, and the receiving end of the receiving wavelength selection switch receives the receiving control code word generated by the code word control unit as a control signal, so that the receiving The plurality of output ends of the wavelength selection switch respectively output the modulated coded optical carrier signals output by the optical modulation modules of the transmit coding unit; the plurality of output ends of the receive wavelength selection switches are respectively connected to the plurality of outputs An input end of an optical narrow pulse receiving module, an output end of an optical narrow pulse receiving module is respectively connected to an input end of the receiving wavelength division multiplexer, an output end of the receiving wavelength division multiplexer and the WDM system The light receiver is connected. The narrow pulse receiving module detects the modulated encoded optical carrier signal received therefrom to obtain a modulated optical signal and outputs it to a corresponding input port of the receiving wavelength division multiplexer.

[0036] In this embodiment, the control codeword includes a transmit control codeword and a receive control codeword, and the transmit control codeword and the receive control codeword are respectively sent to the transmit coding unit and the The receiving decoding unit is described. The function of the transmission control codeword and the reception control codeword is such that the above-mentioned transmission wavelength selection and reception wavelength selection are respectively outputting signals at wavelengths corresponding to the set requirements at their different output terminals, so that this is achieved in advance. In this embodiment, the foregoing transmit control codeword and the receive control codeword may be the same (may be combined into one control codeword), or may be different, and the specific selection of the transmit wavelength selection and the reception wavelength selection is required. Depending on the situation.

[0037] The device for performing security protection on the WDM optical transmission signal performs channel separation processing on the optical wavelength division multiplexed signal from the WDM optical transmitter, and each channel is separately received for optical-electrical conversion, and the narrow signal is modulated by the electrical signal. Pulse (ie, coded optical carrier signal), narrow-light pulse generated by a broad-spectrum supercontinuum source, or generated by a plurality of narrow-width semiconductor gain-dependent lasers of different wavelengths, after wavelength selection (WSS, Wavel ength Selective Switch Module, WSS has one or more input ports, N output ports, controlled by computer, can output any port input light or any part of the input port light to any output port of W SS (port 1 N), one input port can input one or more wavelengths, and one output port can output one or more wavelengths as expected. By controlling the wavelength of each output port of the WSS, the optical carrier of the channel can be converted. The optical carrier of each channel is subjected to frequency hopping change with time, and the change rule will follow the designed code word.

[0038] In this embodiment, the receiving and decoding unit of the WDM optical transmission signal security protection device is composed of a WSS-Drop wavelength selection switch module, a plurality of optical narrow pulse receiving modules, a wavelength division multiplexer, and a decoding conversion control system (FIG. Not shown in the middle), as shown in Figure 3. The WDM optical code transmitted from the transmission fiber enters the WSS-Drop receiving wavelength selection switch module, and the WSS-Drop receives the wavelength selection switch under the action of the decoding conversion control signal (ie, the reception control code word) sent by the decoding conversion control system. Each output port outputs a single optical carrier, and the wavelength of the carrier is corresponding to the code conversion, so that the wavelength of the single-wave optical signal outputted by each output port (1---N) of the WSS-Drop remains unchanged, and is still λ ρ λ ₂ , respectively. ..., λ _Ν . Each signal enters a plurality of narrow-narrow pulse receiving modules, and is restored to each single-channel user signal of a different wavelength, and is multiplexed into a WDM optical signal by a wavelength division multiplexer. Wherein, when required, the narrow-narrow pulse receiving module sequentially expands the narrow pulse of the light obtained by delaying or expanding, and then returns to the format of the channel optical signal of the WDM and outputs the format.

[0039] Transform coding is Yaoan control system designed to control the coding rule brightest optical carrier wavelength, as in the first lap ^ inches, for the first channel to the second channel are arranged Ν different wavelengths person ₁ To the person ^ In the second inter-turn τ ₂ , change the wavelength of each channel; in the third inter-segment 1 ₃ , change the wavelength of each channel, and so on, as shown in Figure 4. For any channel, the carrier wavelength changes with time. The determination of the length of the inter-turn, and the selection of its wavelength are determined according to the designed coding transformation law. The segments are not necessarily equal. In this way, the eavesdropper can not obtain the user information by using the spectrum analyzer, so that the system plays a security role.

[0040] Referring to FIG. 5, in this embodiment, a method for security protection of optical signals transmitted in a WDM system is further included, which includes the following steps: [0041] Step S1 l demultiplexes the multiplexed signal of the WDM system to obtain a user signal: In this step, the WD is

The multiplexed optical signal output by the M system is decomposed and photoelectrically converted according to the channel to obtain a user signal of each channel.

[0042] Step S12 respectively modulates the obtained user signal to the corresponding coded optical carrier signal, wherein the wavelength of the encoded optical carrier signal varies with the time: In this step, the obtained user signals of each channel are respectively for the channel. Encoded optical carrier for modulation; wherein, a control codeword is generated and used for optical signal processing in this step and a later step, respectively, and the control codeword is used to control parameters of the coded optical carrier of each channel to generate different, corresponding to The coded optical carrier of each channel or control outputs a modulated, coded optical carrier signal of a different channel.

[0043] Step S13 multiplexes the obtained plurality of modulated coded optical carrier signals to obtain WDM optical coding: In this step, since a plurality of modulated coded optical carrier signals are generated in the above steps, each channel is modulated. The latter coded optical carrier multiplexing results in WDM optical coding.

[0044] Step S14 transmits the WDM optical code to the transmission fiber: In this step, the WDM optical code is transmitted to the transmission fiber.

[0045] Step S15 receives the WDM optical code, and obtains the coded optical carrier signal modulated by the user output: In this step, the WDM optical code (optical signal) is transmitted on the transmission fiber and then reaches the receiving end, where the WDM Before the optical code has entered the optical receiver of the WDM system, it is processed, that is, the WDM optical code is received, and the WDM optical code is demultiplexed into modulated modulated optical carrier signals of each channel.

[0046] Step S16 demodulates the output modulated optical carrier signals to obtain respective user signals: In this step, the obtained modulated encoded optical carrier signals are demodulated to obtain user signals of respective channels. .

[0047] Step S17 multiplexes the obtained user signal and outputs it to the optical receiver of the WDM system: In this step, the obtained user signals of each channel are multiplexed into WDM optical signals, and transmitted to the optical receiver of the WDM system.

[0048] In this embodiment, the coded optical carriers of each channel respectively comprise a plurality of set inter-turn units arranged in sequence, and the wavelength of the light in each set inter-turn unit is different from the adjacent set inter-turn time. The wavelength of light in the cell; the wavelength of the light in the same number of the coded optical carrier of each channel is different. By control The code word controls the wavelength selection switch so that each set wavelength component input to the wavelength selection signal is respectively output to the output end of the wavelength selection switch, thereby obtaining a coded optical carrier signal or a modulated coded optical carrier. signal.

The above-mentioned embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is not to be construed as limiting the scope of the invention. It should be noted that various modifications and improvements can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the invention should be subject to the appended claims.

Industrial applicability

[0050] Enter the paragraph of industrial applicability description here.

Sequence table free content

[0051] Type the sequence table free content description paragraph here.

Claims

Claim

[Claim 1] A device for security protection of transmitted optical signals in a WDM system, characterized in that

The method includes: transmitting a coding unit: connecting between the optical transmitter of the WDM and the transmission fiber, optically decomposing the WDM optical signal into N single-wavelength optical signals, optically encoding the obtained optical signals, and Combining the N channels of the optically encoded signals into a WDM optical coded signal, and transmitting the WDM optical coded signal to the transmission fiber; wherein, the carrier wavelength of the coded optical carrier of each channel is different;

Receiving the decoding unit: receiving the WDM optical coded signal, converting the WDM optical coded signal into an optical signal of the WDM system, and transmitting the optical signal to the optical receiver of the WDM system; the codeword control unit: generating the control codeword and transmitting the control code word respectively Transmitting coding unit and receiving decoding unit, wherein the control codeword is used to control parameters of the coded optical carrier of each channel to generate different decoded optical carriers corresponding to each channel or different decoded output signals of each channel Carrier signal.

[Claim 2] The apparatus for security protection of transmitted optical signals in a WDM system according to claim 1, wherein the coded optical carriers of each channel respectively comprise a plurality of set inter-turn units arranged in sequence, The wavelength of the light in each of the set day units is different from the wavelength of the light in the adjacent set day unit; the wavelength of the light in the set number of the same number of coded optical carriers of each channel is different.

[Claim 3] The apparatus for security protection of a transmitted optical signal in a WDM system according to claim 2, wherein the transmission coding unit further comprises a wave decomposition multiplexer, a plurality of light receiving modules, and a plurality of a light modulation module, a light source, and a transmit wavelength division multiplexer; the wave decomposition multiplexer includes an input coupled to an optical transmitter output of the WDM system and a plurality of outputs, the wave decomposition multiplexing The plurality of output ends of the device are respectively connected to the input end of a light receiving module, and the output end of one light receiving module is connected to the modulation signal input end of a light modulation module; the light source comprises a plurality of encoded optical carrier signal output ends. An input of an optical modulation module is connected to a coded optical carrier signal output; the optical modulation module The output end is connected to the input end of the transmitting wavelength division multiplexer, and the output end of the transmitting wavelength division multiplexer is connected to the transmission optical fiber; the number of output ends of the wave demultiplexing multiplexer and the number of optical receiving modules The number of optical modulation modules, the number of encoded optical carrier outputs, and the number of input terminals of the transmitting wavelength division multiplexing module are equal.

[Claim 4] The apparatus for security protection of transmitted optical signals in a WDM system according to claim 3, wherein the light source comprises a broad spectrum light source and an emission wavelength selection, and the emission wavelength is selected. The switch includes an input end, a control end, and a plurality of output ends; the wide-spectrum light source generates a wide-spectrum optical signal and outputs to the input end of the transmit wavelength selection switch, and the control end of the transmit wavelength selection switch receives the code word The transmission control code word generated by the control unit is used as a code conversion control signal, so that the plurality of output ends of the transmission wavelength selection are respectively obtained from the optical signals input by the wide spectrum light source and respectively output and meet the requirements of the control code word. Encoded optical carrier signal.

[Claim 5] The apparatus for performing security protection on a transmitted optical signal in a WDM system according to claim 4, wherein the receiving and decoding unit comprises a receiving wavelength selection switch, a plurality of optical narrow pulse receiving modules, and Receiving a wavelength division multiplexer; the receiving wavelength selection switch comprises an input terminal, a control terminal and a plurality of output terminals; the input end of the receiving wavelength selection switch is connected to the transmission fiber, and the receiving wavelength is selected The control terminal of the switch receives the receive control code word generated by the codeword control unit as a control signal, so that the plurality of output terminals of the receive wavelength selection switch respectively output the output of each light modulation module in the transmit coding unit, a modulated encoded optical carrier signal; a plurality of output terminals of the receiving wavelength selective switch are respectively connected to input ends of the plurality of narrow pulse receiving modules, and outputs of an optical narrow pulse receiving module are respectively connected to the An input of the receive wavelength division multiplexer is coupled to an optical receiver of the WDM system.

[Claim 6] The apparatus for security protection of a transmitted optical signal in a WDM system according to claim 5, wherein the optical narrow pulse receiving module performs the modulated encoded optical carrier signal received thereon Detecting, a modulated optical signal is obtained and output to a corresponding input port of the receiving wavelength division multiplexer.

[Claim 7] The device for security protection of transmitted optical signals in a WDM system according to claim 6. The control codeword includes a transmit control codeword and a receive control codeword, and the transmit control codeword and the receive control codeword are respectively sent to the transmit coding unit and the Receive decoding unit.

[Claim 8] A method for security protection of optical signals transmitted in a WDM system, characterized in that

After the WDM system outputs the multiplexed optical signal, the optical signal is processed as follows: the WDM optical signal is decomposed and photoelectrically converted according to the channel, and the N single-wavelength optical signal is used to illuminate the obtained optical signals. Encoding the modulated optical carrier of each channel to obtain WDM optical coding, and transmitting the WDM optical coding to the transmission optical fiber; wherein, the carrier wavelength of the coded optical carrier of each channel is different;

After the WDM system receives the optical signal transmitted on the transmission fiber after the processing, the optical signal is processed as follows:

Receiving the WDM optical code, demultiplexing the WDM optical code into a modulated coded optical carrier signal of each channel, and performing demodulation to obtain a user optical signal of each channel, and obtaining the obtained user optical signal of each channel. An optical signal multiplexed into WDM and transmitted to an optical receiver of the WDM system;

Wherein, the control codewords are generated and used for the optical signal processing described above, wherein the control codewords are used to control parameters of the encoded optical carriers of the respective channels to generate different encoded optical carriers or control outputs corresponding to the respective channels. Modulated coded optical carrier signal for each channel

[Claim 9] The method according to claim 8, wherein the coded optical carriers of each channel respectively comprise a plurality of set inter-turn cells arranged in sequence, and the wavelengths of light in each set of inter-turn cells are different The wavelength of light in the adjacent set-turn unit; the wavelength of the light in the set number of the same number of coded optical carriers of each channel is different.

[Claim 10] The method according to claim 9, wherein the wavelength selection is controlled by controlling the codeword so that each of the set wavelength components input to the wavelength selection signal is respectively output to the wavelength The output of the gate is selected to obtain a coded optical carrier signal or a modulated coded optical carrier signal.