WO2022037245A1

WO2022037245A1 - Four-channel ultra-high-speed two-way otdm secure communication system

Info

Publication number: WO2022037245A1
Application number: PCT/CN2021/101651
Authority: WO
Inventors: 钟东洲; 曾能; 杨华; 徐喆
Original assignee: 五邑大学
Priority date: 2020-08-18
Filing date: 2021-06-22
Publication date: 2022-02-24
Also published as: CN111970105B; CN111970105A

Abstract

Disclosed is a four-channel ultra-high-speed two-way OTDM secure communication system, comprising two optical fiber generation and wave division modules, two multiplexing delay and modulation modules, and two optical fiber beam splitting and modulation modules. According to embodiments of the present invention, the chaotic synchronization between two spinning VCSELs is implemented by performing external light injection on the two spinning VCSELs. The asymmetry of the two spinning VCSELs is caused by uneven propagation delay, such that such asymmetry is eliminated to a great extent by injecting elliptically polarized light into the two spinning VCSELs. Moreover, by means of further optimization of parameters, high-quality in-phase and anti-phase lead/lag chaotic synchronization is achieved, and four-channel ultra-high-speed two-way OTDM secure communication is achieved.

Description

A four-channel ultra-high-speed two-way OTDM secure communication system

technical field

The invention relates to the technical field of secure communication, in particular to a four-channel ultra-high-speed two-way OTDM secure communication system.

Background technique

Optically pumped spin-polarized vertical-cavity surface-emitting lasers (spin VCSELs) have low thresholds, independent control of output polarization state and intensity, ultrafast dynamics, and large modulation bandwidths (~200 GHz) Etc. Taking advantage of these properties, optically pumped spin VCSELs have new application prospects in the fields of optical communication, optical information processing, data storage, quantum computing, and biochemical sensing. Various forms of ultrafast instability can be observed in optically pumped spin VCSELs, including periodic oscillations, polarization inversion, and chaotic dynamical behavior. The chaotic dynamics of optically pumped spin VCSELs has potentially important applications in ultrafast optical chaotic computing, ultrafast random number generation, and ultrafast chaotic secure communications.

Due to the advantages of mutually coupled semiconductor lasers (MCSLs) such as high security and bidirectional information transmission capability, more and more researches have been carried out on their chaotic synchronization and communication. It is demonstrated that by using self-feedback for two MCSLs, real-time chaos synchronization and lead/lag chaos synchronization can be established between them. However, stable real-time synchronization is difficult to obtain for face-to-face mutual-coupled conventional lasers including electrically pumped spin VCSELs, and definitively stable lead/lag synchronization requires a certain detuning between MCSLs. In order to achieve stable real-time synchronization and well-defined and stable lead/lag synchronization, some complex systems of MCSLs have been proposed. However, in these schemes, although chaotic synchronization can be achieved with equal forward and backward propagation delays, the realization of chaotic synchronization faces new challenges due to the asymmetry between the two MCSLs. challenge. More importantly, in the mutually coupled conventional lasers, it is difficult to realize multi-channel OTDM chaotic secure communication due to its dynamic characteristics on the order of nanoseconds.

Therefore, the existing technology still needs to be further improved and improved.

SUMMARY OF THE INVENTION

In view of the above-mentioned technical problems, the present invention provides a four-channel ultra-high-speed two-way OTDM secret communication system to realize high-quality in-phase and reverse phase lead/lag chaotic synchronization and channel ultra-high-speed two-way OTDM secret communication.

In order to solve the above technical problems, the embodiment of the present invention provides a four-channel ultra-high-speed two-way OTDM secure communication system, including two optical fiber generation and demultiplexing modules, two multiplexing delay modulation modules and two optical fiber beam splitting modulation modules, wherein ,

Each fiber generation and demultiplexing module includes a feedback laser, a spin VCSEL, and a bidirectional fiber circulator, respectively. The polarized light generated by the feedback laser passes through the spin VCSEL and the bidirectional fiber circulator in turn to generate two paths of light waves. The light waves are respectively injected into the optical fiber beam splitting modulation module and the multiplexing delay module;

Each multiplexing delay modulation module includes a fiber polarization beam splitter, two delay multiplexing modules, a fiber polarization controller, and a fiber beam splitter respectively, and the fiber polarization beam splitter generates all the components of the wave splitting module through the fiber. The injection of one of the generated light waves generates two polarized waves from the light waves, and the two polarized waves are modulated and delayed multiplexed with four input optical signals through a delay multiplexing module respectively, and after two delay multiplexing The two light waves generated by the module respectively modulated and time-delayed are polarized by the fiber polarization controller to generate one light wave fiber. The light wave fiber generates two light waves through the fiber beam splitter. One of the light waves generated by the fiber beam splitter Injecting into the optical fiber polarization beam splitter of the optical fiber beam splitting modulation module, and injecting another light wave into the bidirectional optical fiber circulator of the optical fiber generation wave splitting module;

Each optical fiber beam splitting modulation module includes two optical fiber polarization beam splitters and two demodulation filter modules respectively, and the two optical fiber polarization beam splitters respectively generate one of the light waves generated by the wave splitting module and the complex optical fiber through the optical fiber. Using the injection of one of the light waves generated by the delay modulation module, the injected two light waves generate two polarized waves respectively, and the two polarized waves are injected into the two demodulation filter modules respectively. The filtering modules are respectively synchronously demodulated and filtered to generate four output optical signals.

Further, the optical fiber generation and demultiplexing module includes a first optical fiber generation and demultiplexing module and a second optical fiber generation and demultiplexing module, and the first optical fiber generation and demultiplexing module includes a first feedback laser, a first polarization control circuit, a first A spin VCSEL and a first bidirectional fiber circulator, the second fiber generating and demultiplexing module includes a second feedback laser, a second polarization control circuit, a second spin VCSEL and a second bidirectional fiber circulator, the first feedback The polarized light emitted by the laser is injected into the first spin VCSEL in parallel via the first polarization control circuit, and the polarized light emitted by the second feedback laser is injected in parallel into the second spin VCSEL via the second polarization control circuit.

Further, a first fiber isolator and a second fiber isolator are respectively provided between the first feedback laser and the first polarization control circuit, and between the second feedback laser and the second polarization circuit to make the polarized light unidirectional. spread.

Further, the multiplexing delay modulation module includes a first multiplexing delay modulation module and a second multiplexing delay modulation module, and the first multiplexing delay modulation module includes a first optical fiber polarization beam splitter, a second multiplexing delay modulation module. a delay multiplexing module, a second delay multiplexing module, a first fiber polarization controller and a first fiber beam splitter; the second multiplex delay modulation module includes a second polarization beam splitter, a third delay a time multiplexing module, a fourth delay multiplexing module, a second optical fiber polarization controller and a second optical fiber beam splitter; the bidirectional optical fiber circulator includes a first bidirectional optical fiber circulator and a second bidirectional optical fiber circulator;

One of the light waves generated by the first bidirectional fiber circulator is injected into the first fiber polarization beam splitter to split into two polarized waves, and the two polarized waves are injected into the first delay multiplexing module and the second delay respectively. The multiplexing module synthesizes one optical fiber through the first optical fiber polarization controller, one optical fiber generates two optical waves through the first optical fiber beam splitter, and one of the optical waves generated by the first optical fiber beam splitter is injected into the second bidirectional optical fiber circulator;

One of the light waves generated by the second bidirectional optical fiber circulator is injected into the second optical fiber polarization beam splitter to split into two polarized waves, and the two polarized waves are respectively injected into the third delay multiplexing module and the fourth delay multiplexer. The time multiplexing module synthesizes one optical fiber through the second optical fiber polarization controller, one optical fiber generates two optical waves through the second optical fiber beam splitter, and one of the optical waves generated by the second optical fiber beam splitter Inject the first bidirectional fiber optic circulator.

Further, the first delay multiplexing module, the second delay multiplexing module, the third delay multiplexing module and the fourth delay multiplexing module respectively include a third fiber beam splitter and four modulators. , four delayers and an optical multiplexer, each of the modulators corresponds to each delayer one-to-one;

The two polarized waves injected by the first optical fiber polarization beam splitter are respectively injected into the first delay multiplexing module and the second delay multiplexing module, and are respectively passed through the first delay multiplexing module and the second delay multiplexing module. The third fiber beam splitter of the delay multiplexing module is divided into four paths of light waves, and the four paths of light waves divided by the third fiber beam splitter are modulated with the input signals of the four paths of light waves through the four modulators respectively, and the four delay devices Delay and inject into the first optical fiber polarization controller after multiplexing by the optical multiplexer;

The two polarized waves injected by the second optical fiber polarization beam splitter are respectively injected into the third delay multiplexing module and the fourth delay multiplexing module, and are respectively passed through the third delay multiplexing module and the fourth delay multiplexing module. The third fiber beam splitter of the delay multiplexing module is divided into four paths of light waves, and the four paths of light waves divided by the third fiber beam splitter are respectively modulated by four modulators and four paths of light wave input signals, and delayed by four delay devices. , and the optical multiplexer is multiplexed and then injected into the second optical fiber polarization controller.

Further, the optical fiber splitting modulation module includes a first optical fiber splitting modulation module and a second optical fiber splitting modulation module, and the first optical fiber splitting modulation module includes a third optical fiber polarization splitter, a fourth optical fiber polarization splitter. a beam splitter, a first demodulation filter module and a second demodulation filter module, the second fiber beam splitting modulation module includes a fifth fiber polarization beam splitter, a sixth fiber polarization beam splitter, a third demodulation filter module and the fourth demodulation filter module;

The other light wave of the first optical fiber beam splitter is injected into the third optical fiber polarization beam splitter, and two polarized waves are generated by the third optical fiber polarization beam splitter. The two polarized waves are injected into the first demodulation filter module and the second demodulation filter module respectively; the other channel of the second bidirectional fiber circulator is injected into the fourth fiber polarization beam splitter, The four-fiber polarization beam splitter generates two paths of polarized waves, and the two paths of polarized waves generated by the fourth fiber polarization beam splitter are respectively injected into the first demodulation filter module and the second demodulation filter module;

Another light wave of the second optical fiber beam splitter is injected into the sixth optical fiber polarization beam splitter, and two paths of polarized waves are generated by the sixth optical fiber polarization beam splitter. The two polarized waves are injected into the third demodulation filter module and the fourth demodulation filter module respectively; the other channel of the first bidirectional optical fiber circulator is injected into the fifth optical fiber polarization beam splitter, The five-fiber polarization beam splitter generates two polarized waves, and the two polarized waves generated by the fifth fiber polarization beam splitter are respectively injected into the third demodulation filter module and the fourth demodulation filter module.

Further, the first demodulation filter module, the second demodulation filter module, the third demodulation filter module and the fourth demodulation filter module respectively comprise a fourth fiber beam splitter, an optical time division multiplexer, four delayers, four subtraction filter modules and eight photodetectors, the fourth fiber beam splitter corresponds to four photodetectors, and the optical time division multiplexer corresponds to four delayers and four photodetectors device;

One of the polarized waves generated by the third optical fiber polarization beam splitter and one of the polarized waves generated by the fourth optical fiber polarization beam splitter pass through the optical time division multiplexer and the optical time division multiplexer of the first demodulation filter module, respectively. The demultiplexing of the second demodulation and filtering module is to convert four paths of light waves, the delay of the delayer, and the conversion of the four photodetectors into four paths of electrical signals, and another path of polarization generated by the third fiber polarization beam splitter The wave and the other polarized wave generated by the fourth fiber polarization beam splitter are respectively divided into the fourth fiber beam splitter of the first demodulation filter module and the fourth fiber beam splitter of the second demodulation filter module. The four paths of light waves and the four optical detectors are converted into four paths of electrical signals, and the four paths of electrical signals converted by the four optical detectors corresponding to the optical time division multiplexer are the same as the four paths of electrical signals converted by the fourth optical fiber beam splitter. The four-way electrical signals converted by the photodetector are demodulated and filtered synchronously by four subtraction filtering modules to generate four-way output optical signals;

One of the polarized waves generated by the fifth optical fiber polarization beam splitter and one of the polarized waves generated by the sixth optical fiber polarization beam splitter pass through the optical time division multiplexer and the optical time division multiplexer of the third demodulation filter module, respectively. The demultiplexing of the fourth demodulation filter module is four-way light wave, the delay of the delay device, and the four optical detectors are converted into four-way electrical signals, and the other channel of polarization generated by the fifth optical fiber polarization beam splitter The wave and another polarized wave generated by the sixth optical fiber polarization beam splitter are respectively divided into the fourth optical fiber beam splitter of the third demodulation filtering module and the fourth optical fiber beam splitter of the fourth demodulation filtering module. The four paths of light waves and the four optical detectors are converted into four paths of electrical signals, and the four paths of electrical signals converted by the four optical detectors corresponding to the optical time division multiplexer are the same as the four paths of the electrical signals corresponding to the fourth optical fiber beam splitter. The four paths of electrical signals converted by the photodetector are respectively demodulated and filtered synchronously by four subtraction filter modules to generate four paths of output optical signals.

Further, neutral density filters are respectively provided before and after the spin VCSEL to control the light intensity.

Further, both the first polarization control circuit and the second polarization control circuit include an optical fiber polarizer, an optical fiber polarization controller and an optical fiber depolarizer for converting two polarization components of polarized light.

Further, the four input optical signals are four different input optical signals.

The embodiment of the present invention is a four-channel ultra-high-speed two-way OTDM secure communication system. By injecting external light into two spin VCSELs, the chaotic synchronization between them is realized. , so this asymmetry is largely eliminated by injecting them with elliptically polarized light. And by further optimizing the parameters, high-quality in-phase and anti-phase lead/lag chaotic synchronization is achieved, and four-channel ultra-high-speed two-way OTDM secure communication is realized.

Description of drawings

FIG. 1 is a preferred structural block diagram of a four-channel ultra-high-speed two-way OTDM secure communication system provided by an embodiment of the present invention.

FIG. 2 is another preferred structural block diagram of a four-channel ultra-high-speed two-way OTDM secure communication system provided by an embodiment of the present invention.

FIG. 3 is a device connection structure diagram corresponding to the block diagram shown in FIG. 2 .

FIG. 4 is an optical path structure diagram of the PCOC in FIG. 3 .

FIG. 5 is an optical path structure diagram of the DMM in FIG. 3 .

FIG. 6 is an optical path structure diagram of the SMM in FIG. 3 .

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

The terms "first", "second" and the like in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances so that the embodiments described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

Referring to FIG. 1, FIG. 2 and FIG. 3, a four-channel ultra-high-speed two-way OTDM secure communication system provided by the embodiment of the present invention includes two optical fiber generation and demultiplexing modules, two multiplexing delay modulation modules and two optical fiber splitting modules. Beam modulation module, each fiber generation and demultiplexing module respectively includes a feedback laser, a spin VCSEL and a bidirectional fiber circulator, and the polarized light generated by the feedback laser passes through the spin VCSEL and the bidirectional fiber circulator in turn to generate two paths light waves, and the two paths of the light waves are respectively injected into the optical fiber beam splitting modulation module and the multiplexing delay module.

Each multiplexing delay modulation module includes a fiber polarization beam splitter, two delay multiplexing modules, a fiber polarization controller, and a fiber beam splitter respectively, and the fiber polarization beam splitter generates all the components of the wave splitting module through the fiber. The injection of one of the generated light waves generates two polarized waves from the light waves, and the two polarized waves are modulated and delayed multiplexed with four input optical signals through a delay multiplexing module respectively, and after two delay multiplexing The two light waves generated by the module respectively modulated and time-delayed are polarized by the fiber polarization controller to generate one light wave fiber, and the light wave fiber generates two light waves through the fiber beam splitter, and one of the light waves generated by the fiber The optical fiber polarization beam splitter of the optical fiber beam splitting modulation module is injected, and another light wave is injected into the bidirectional optical fiber circulator of the optical fiber generation wave splitting module.

The spin VCSEL used in the present invention not only has the advantages of flexible spin control of the laser output, fast dynamic behavior of femtosecond order, and large modulation bandwidth, etc., but also has more control parameters, such as pumping magnitude , polarization ellipticity, etc. Taking advantage of these favorable properties, chaotic synchronization between two MCOP-spin VCSELs is achieved by external optical injection with unequal forward and backward propagation delays.

The two spin VCSELs are coupled to each other and are respectively injected by the external light field from the feedback laser to perform light polarization and corresponding modulation and multiplexing. When two polarization components of the polarized light appear in the two mutually coupled spin VCSELs When there is a lag synchronization between the two, two-channel advanced OTDM secure communication can be performed; and when there is a pre-synchronization between the two polarization components of the polarized light, a dual-channel lag OTDM secure communication can be realized, so the system can realize four-channel advanced OTDM secure communication. Two-way OTDM secure communication.

The secure communication system is described in detail below.

The optical fiber generation and demultiplexing module in this embodiment includes a first optical fiber generation and demultiplexing module 11 and a second optical fiber generation and demultiplexing module 12, and the first fiber generation and demultiplexing module 11 includes a first feedback laser 111 (DFB ₁ ) , a first polarization control circuit 112 (PCOC ₁ ) and a first spin VCSEL 113 (VCSEL ₁ ), the second fiber generation and demultiplexing module 12 includes a second feedback laser 121 (DFB ₂ ), a second polarization control circuit 122 and For the second spin VCSEL 123, the polarized light emitted by the first feedback laser 111 is injected into the first spin VCSEL 113 (VCSEL _{1 ) in parallel via the first polarization control circuit 112 (PCOC 1} ₎ , and the second feedback laser 121 (DFB ₂ ) The emitted polarized light is injected in parallel into the second spin VCSEL 123 (VCSEL _{2 ) via the second polarization control circuit 122 (PCOC 2} ₎ .

The VCSEL ₁ and the VCSEL ₂ in this embodiment are coupled to each other and are injected by the external light fields of the DFB ₁ and the DFB ₂ , respectively. For the convenience of distinction, in this embodiment, the x-polarization component (XPC) and the Y-polarization component (YPC) output by the VCSEL ₁ are named 1-XPC and 1-YPC respectively, and the XPC and YPC output by the VCSEL ₂ are respectively defined as 2- XPC and 2-YPC. In order to ensure that the polarized light of DFB ₁ and DFB ₂ is injected into the XPC and YPC of VCSEL ₁ and VCSEL ₂ in parallel, it is necessary to use two polarization control optical paths (PCOC ₁ and PCOC ₂ ) respectively to convert the polarized light output from DFB ₁ and DFB ₂ Light waves are divided into XPC and YPC.

In this embodiment, the first polarization control circuit 112 (PCOC ₁ ) and the second polarization control circuit 122 (PCOC ₂ ) both include a fiber polarizer (FP), a fiber polarization controller (FPC), and a fiber depolarizer ( FD) is used to convert the two polarized components of polarized light. For the polarization control function of the two polarization control optical paths (PCOC ₁ and PCOC ₂ ), please refer to Figure 4, PCOC ₁ and PCOC ₂ are used for the conversion between XPC and YPC through fiber polarizer (FP), fiber polarization controller ( It is realized by passive devices such as FPC) and fiber depolarizer (FD), and the polarization control function of the polarization control optical path belongs to the well-known technology, and will not be described in detail here.

In this embodiment, referring to FIG. 3 again, between the first feedback laser 111 (DFB ₁ ) and the first polarization control circuit 112 (PCOC ₁ ), and between the second feedback laser 121 (DFB ₂ ) and the second polarization circuit ( A first fiber isolator (FI ₁ ) and a second fiber isolator (FI ₂ ) are respectively provided between the PCOC ₂ ) to make the polarized light propagate in one direction. Neutral density filters (NDFs) are arranged before and after the spin VCSEL to control the light intensity, that is, NDF ₁ and NDF ₂ are respectively arranged before and after VCSEL ₁ , and NDF ₃ and NDF are arranged before and after VCSEL ₂ respectively. _4. Through the neutral density filter, the light intensity in and out of the spin VCSEL can be effectively controlled.

The bidirectional fiber circulators (BFCs) of this embodiment are used to realize bidirectional propagation of light waves, and include a first bidirectional fiber circulator 114 (BFC ₁ ) and a second bidirectional fiber circulator 124 (BFC ₂ ). BFC ₁ injects VCSEL ₁ into The polarized light is divided into two light waves, one of which is injected into one of the multiplexing delay modulation modules, and the other is injected into one of the fiber beam splitting modulation modules. BFC ₂ divides the polarized light injected by VCSEL ₂ into two light waves, one of which is a light wave Another multiplexing delay modulation module is injected, and another light wave is injected into another fiber splitting modulation module, so that the optical fibers are mutually coupled in each multiplexing delay modulation module and the fiber splitting modulation module.

Specifically, the multiplexing delay modulation module in this embodiment includes a first multiplexing delay modulation module 21 and a second multiplexing delay modulation module 22, and the first multiplexing delay modulation module 21 includes a first optical fiber polarization splitter 211 (FPBS ₁ ), first delay multiplexing module 212 (1-DMM), second delay multiplexing module 213 (2-DMM), first fiber polarization controller 214 (FPC ₁ ) and first fiber Beam splitter 215 (FBS ₄ ); the second multiplexing delay modulation module 22 includes a second polarization beam splitter 221 (FPBS ₂ ), a third delay multiplexing module 222 (3-DMM), a fourth delay multiplexer A module 223 (4-DMM), a second fiber polarization controller 224 (FPC ₂ ), and a second fiber beam splitter 225 (FBS ₆ ) are used.

One of the light waves generated by the first bidirectional fiber circulator 114 (BFC ₁ ) is injected into the first fiber polarization beam splitter 211 (FPBS ₁ ) to split into two polarized waves (1-XPC and 1-YPC). The waves (1-XPC and 1-YPC) are injected into the first delay multiplexing module 212 (1-DMM) and the second delay multiplexing module 213 (2-DMM), respectively, and pass through the first fiber polarization controller 214 (FPC). ₁ ) Synthesize one optical fiber (Fiber), one of the optical fibers (Fiber) generates two optical waves through the first optical fiber beam splitter 215 (FBS ₄ ₎ , and the first optical fiber One light wave is injected into the second bidirectional fiber circulator 124 (BFC ₂ ), and another light wave generated by the first fiber beam splitter 215 (FBS ₄ ) is injected into the first fiber beam splitting modulation module 31 .

One of the light waves generated by the second bidirectional fiber circulator 124 (BFC ₂ ) is injected into the second fiber polarization beam splitter (FPBS ₂ ) to split into two polarized waves (2-XPC and 2-YPC), the two polarized waves The waves (2-XPC and 2-YPC) are injected into the third delay multiplexing module 222 (3-DMM) and the fourth delay multiplexing module 223 (4-DMM), respectively, and pass through the second fiber polarization controller 224 (FPC). ₂ ) Synthesize one light wave fiber (Fiber), one light wave fiber (Fiber) generates two light waves through the second fiber beam splitter 225 (FBS ₆ ), and the second fiber beam splitter 225 (FBS ₆ ) generates two light waves. One of the generated light waves is injected into the first bidirectional fiber circulator 114 (BFC ₁ ), and the other light wave generated by the second fiber beam splitter 225 (FBS ₆ ) is injected into the second fiber beam splitting modulation module 32 .

In this embodiment, the first delay multiplexing module 212 (1-DMM), the second delay multiplexing module 213 (2-DMM), the third delay multiplexing module 222 (3-DMM) and the fourth delay multiplexing module 222 (3-DMM) The delay multiplexing module 223 (2-DMM) includes a third fiber beam splitter (FBS), four modulators (MD), four delayers (DL), and an optical multiplexer (OTM), respectively. A modulator (MD) corresponds to a delay device (DL) one-to-one. The specific optical path structure of the delay multiplexing module in this embodiment is shown in FIG. 4 . The polarized wave output by the optical fiber polarization beam splitter is divided into four optical waves by the third optical beam splitter, and the four optical waves are respectively input by one modulator and one optical wave. Signals (m _j1 , m _j2 , m _j3 and m _j4 , j=1, 2, 3, 4) are modulated after being processed by the delays (dt ₁ , dt ₂ , dt ₃ and dt ₄ ) of the delayers Four light waves are multiplexed by an optical multiplexer to produce one light wave signal.

Specifically, one of the polarized waves (1-XPC) injected by the first fiber polarization beam splitter 211 (FPBS ₁ ) is injected into the first delay multiplexing module 212 (1-DMM), and the first delay multiplexing The third fiber beam splitter (FBS) of the module 212 (1-DMM) is divided into four light waves, and the four light waves divided by the third fiber beam splitter (FBS) pass through the four modulators (MD) and the four light waves respectively. Input signal (m ₁₁ , m ₁₂ , m ₁₃ and m ₁₄ ) modulation, four delays (dt ₁ , dt ₂ , dt ₃ and dt ₄ ), and optical multiplexer (OTM) multiplexing injection An optical fiber polarization controller 214 (FPC ₁ ); another polarized wave (1-YPC) injected by the first optical fiber polarization beam splitter 211 (FPBS ₁ ) is injected into the second delay multiplexing module 213 (2-DMM), It is divided into four light waves by the third fiber beam splitter (FBS) of the second delay multiplexing module 213 (2-DMM), and the four light waves divided by the third fiber beam splitter (FBS) pass through four modulators respectively. (MD) modulation with four optical wave input signals (m ₂₁ , m ₂₂ , m ₂₃ and m ₂₄ ), four delays (dt ₁ , dt ₂ , dt ₃ and dt ₄ ), and an optical multiplexer ( OTM) is multiplexed and injected into the first fiber polarization controller 214 (FPC ₁ ).

Similarly, one of the polarized waves (2-XPC) injected by the second fiber polarization beam splitter (FPBS ₂ ) is injected into the third delay multiplexing module 222 (3-DMM), and the third delay multiplexing module 222 (3-DMM) is passed through the third delay multiplexing module. The third fiber beam splitter (FBS) of 222 (3-DMM) is divided into four light waves, and the four light waves divided by the third fiber beam splitter (FBS) are input through four modulators (MD) and four light waves respectively. Signal (m ₃₁ , m ₃₂ , m ₃₃ and m ₃₄ ) modulation, four delays (dt ₁ , dt ₂ , dt ₃ and dt ₄ ), and optical multiplexer (OTM) multiplexing into the second Fiber polarization controller 224 (FPC ₂ ); another polarized wave (2-YPC) injected by the second fiber polarization beam splitter (FPBS ₂ ) is injected into the fourth delay multiplexing module 223223 (4-DMM), The third fiber beam splitter (FBS) of the four-delay multiplexing module 223223 (4-DMM) is divided into four paths of light waves, and the four paths of light waves divided by the third fiber beam splitter (FBS) pass through four modulators (MD ) with four optical wave input signals (m ₄₁ , m ₄₂ , m ₄₃ and m ₄₄ ) modulation, four delayers (dt ₁ , dt ₂ , dt ₃ and dt ₄ ), and an optical multiplexer (OTM) After multiplexing, it is injected into the second fiber polarization controller 224 (FPC ₁ ).

Through the processing of the above-mentioned multiplexing delay modulation module, the externally input four-way optical input signal (or message) and the polarized light injected by the external light field can be combined together for modulation, multiplexing and coding.

In this embodiment, the optical fiber splitting modulation module includes a first optical fiber splitting modulation module 31 and a second optical fiber splitting modulation module 32, and the first optical fiber splitting modulation module 31 includes a third optical fiber polarization beam splitter 311 (FPBS ₃ ), a fourth fiber polarization beam splitter 312 (FPBS ₄ ), a first demodulation filter module 313 (1-SDM) and a second demodulation filter module 314 (2-SDM), the second fiber beam splitting modulation module 32 includes The fifth fiber polarization beam splitter 321 (FPBS ₅ ), the sixth fiber polarization beam splitter 322 (FPBS ₆ ), the third demodulation filter module 323 (3-SDM), and the fourth demodulation filter module 324 (4-SDM ).

Another light wave of the first optical fiber beam splitter 215 (FBS ₄ ) in this embodiment is injected into the third optical fiber polarization beam splitter 311 (FPBS ₃ ), and the third optical fiber polarization beam splitter 311 (FPBS ₃ ) generates two The two polarized waves (1-XPC and 1-YPC) generated by the third fiber polarization beam splitter 311 (FPBS ₃ ) are respectively injected into the first demodulation filter module 313 (1-SDM) and a second demodulation filter module 314 (2-SDM). The other light wave of the second bidirectional fiber circulator 124 (BFC ₂ ) is injected into the fourth fiber polarization beam splitter 312 (FPBS ₄ ), and the fourth fiber polarization beam splitter 312 (FPBS ₄ ) generates two polarization waves (2- XPC and 2-YPC), the two polarized waves (2-XPC and 2-YPC) generated by the fourth fiber polarization beam splitter 312 (FPBS ₄ ) are injected into the first demodulation filter module 313 (1-SDM) and the second Two demodulation filter modules 314 (2-SDM).

Similarly, another light wave of the second fiber beam splitter 225 (FBS ₆ ) is injected into the sixth fiber polarization beam splitter 322 (FPBS ₆ ), and two polarized waves are generated by the sixth fiber polarization beam splitter 322 (FPBS ₆ ) (2-XPC and 2-YPC), the two polarized waves (2-XPC and 2-YPC) generated by the sixth fiber polarization beam splitter 322 (FPBS ₆ ) are respectively injected into the third demodulation filter module 323 (3- SDM) and the fourth demodulation filter module 324 (4-SDM); another light wave from the first bidirectional fiber circulator 114 (BFC ₁ ) is injected into the fifth fiber polarization beam splitter 321 (FPBS ₅ ), and polarized by the fifth fiber The beam splitter 321 (FPBS ₅ ) generates two polarized waves (1-XPC and 1-YPC), and the fifth fiber polarized beam splitter 321 (FPBS ₅ ) generates two polarized waves (1-XPC and 1-YPC) ) are injected into the third demodulation filter module 323 (3-SDM) and the fourth demodulation filter module 324 (4-SDM), respectively.

In this embodiment, the first demodulation and filtering module 313, the second demodulation and filtering module 314, the third demodulation and filtering module 323, and the fourth demodulation and filtering module 324 respectively include a fourth fiber beam splitter (FBS), One optical time division multiplexer (OTD), four delayers (DL), four subtraction filter modules (SMF) and eight photodetectors (PD), the fourth fiber beam splitter (FBS) corresponds to four optical The detector (PD), the optical time division multiplexer (OTD) corresponds to four delayers (DL) and four photodetectors (PD). The specific optical path structure of the demodulation filter module in this embodiment is shown in FIG. 5 . One of the polarized waves generated by the optical fiber polarization beam splitter and one of the polarized waves generated by the optical fiber polarization beam splitter, and one of the two polarized waves passes through The optical time division multiplexer (OTD) demultiplexes into four light waves, and passes through the delay (δt ₁ , δt ₂ , δt ₃ and δt ₄ ) of the delay device (DL), and four photodetectors (PD) Converted into four electrical signals, the other of the two polarized waves is divided into four optical waves by the fourth fiber beam splitter (FBS), and then converted into four electrical signals by the four optical detectors (PD), and then multiplexed. The four-way electrical signals obtained by delay conversion and the four-way electrical signals obtained by beam splitting are respectively demodulated and filtered synchronously by four subtraction filter modules (SMF) to generate four output optical signals (m" _j1 , m" _j2 , m" _j3 and m" _j4 , j=1, 2, 3, 4).

Specifically, one of the polarized waves (1-YPC) generated by the third fiber polarization beam splitter 311 (FPBS ₃ ) is multiplexed by the optical time division multiplexer (OTD) of the first demodulation filter module 313 (1-SDM). It is used as four-way four-way light waves, and is converted into four-way electrical signals through the delay (δt ₁ , δt ₂ , δt ₃ and δt ₄ ) of the delay device (DL), and four photodetectors (PD), the first One of the polarized waves (2-YPC) generated by the four-fiber polarization beam splitter 312 (FPBS ₄ ) is divided into four optical waves by the fourth optical fiber beam splitter (FPS), and then converted into four optical waves by the four optical detectors (PD) Four-channel electrical signal, the four-channel electrical signal obtained by multiplexing delay conversion and the four-channel electrical signal obtained by beam splitting are respectively demodulated and filtered by four subtraction filter modules (SMF) synchronously to generate four-channel output optical signals (m" ₂₁ , m" ₂₂ , m" ₂₃ and m" ₂₄ ).

Another polarized wave (1-XPC) generated by the third fiber polarization beam splitter 311 (FPBS ₃ ) is multiplexed into four by the optical time division multiplexer (OTD) of the second demodulation filter module 314 (2-SDM) Four paths of light waves are converted into four paths of electrical signals through the delay (δt ₁ , δt ₂ , δt ₃ and δt ₄ ) of a delay device (DL), and four photodetectors (PD), and the fourth fiber polarization One of the polarized waves (2-XPC) generated by the beam splitter 312 (FPBS ₄ ) is divided into four optical waves by the fourth fiber beam splitter (FPS), and then converted into four electrical waves by the four optical detectors (PD). Signal, the four-way electrical signal obtained by multiplexing delay conversion and the four-way electrical signal obtained by beam splitting are respectively demodulated and filtered by four subtraction filter modules (SMF) synchronously to generate four output optical signals (m" ₁₁ , m" ₁₂ , m" ₁₃ and m" ₁₄ ).

Similarly, one of the polarized waves (1-YPC) generated by the fifth fiber polarization beam splitter 321 (FPBS ₅ ) is multiplexed by the optical time division multiplexer (OTD) of the third demodulation filter module 323 (3-SDM). It is used as four-way four-way light waves, and is converted into four-way electrical signals through the delay (δt ₁ , δt ₂ , δt ₃ and δt ₄ ) of the delay device (DL), and four photodetectors (PD), the first One of the polarized waves (2-YPC) generated by the six-fiber polarization beam splitter 322 (FPBS ₆ ) is divided into four optical waves by the fourth optical fiber beam splitter (FPS), and then converted into four optical waves by the four optical detectors (PD). Four-channel electrical signal, the four-channel electrical signal obtained by multiplexing delay conversion and the four-channel electrical signal obtained by beam splitting are respectively demodulated and filtered by four subtraction filter modules (SMF) to generate four output optical signals. (m" ₄₁ , m" ₄₂ , m" ₄₃ and m" ₄₄ ).

One of the polarized waves (1-XPC) generated by the fifth fiber polarization beam splitter 321 (FPBS ₅ ) is multiplexed into four by the optical time division multiplexer (OTD) of the fourth demodulation filter module 324 (4-SDM). Four paths of light waves are converted into four paths of electrical signals through the delay (δt ₁ , δt ₂ , δt ₃ and δt ₄ ) of the delay device (DL), and four photodetectors (PD), and the sixth fiber is polarized One of the polarized waves (2-XPC) generated by the beam splitter 322 (FPBS ₆ ) is divided into four optical waves by the fourth fiber beam splitter (FPS), and then converted into four electrical waves by the four optical detectors (PD). Signal, the four-way electrical signal obtained by multiplexing delay conversion and the four-way electrical signal obtained by beam splitting are respectively demodulated and filtered by four subtraction filter modules (SMF) synchronously to generate four output optical signals (m" ₃₁ , m" ₃₂ , m" ₃₃ and m" ₃₄ ).

Through the above-mentioned optical fiber beam splitting modulation module, the present embodiment can demodulate the coded and modulated four-way optical input signals (or messages) to obtain decoded messages (m" _j1 , m" _j2 , m" _j3 and m" _j4 , j=1,2,3,4). However, the four input optical signals in this embodiment are four different input optical signals. Therefore, when the lag synchronization between 1-XPC (1-YPC) and 2-XPC (2-YPC) occurs in the two mutually coupled spin VCSELs of this embodiment, two-channel advanced OTDM secure communication can be performed , and when there is pre-synchronization between 1-XPC (1-YPC) and 2-XPC (2-YPC), two-channel lag OTDM secure communication can be realized.

Through experiments, the system provided by the embodiment of the present invention, under the condition of unequal forward propagation delay and backward propagation delay, injects the in-phase and anti-phase lead/lag chaotic synchronization of the polarization components in the two spin VCSELs through light injection , so that the evolution trajectories of high-quality in-phase and anti-phase lead/lag chaotic synchronization exhibit periodic changes in different parameter spaces, such as propagation delay difference and total normalized pump power, propagation delay difference and pump polarization Ovality, propagation delay difference and injection strength wait. By optimizing these key parameters, two spin VCSELs can achieve high-quality in-phase and anti-phase lead/lag chaotic synchronization when the propagation delay difference is fixed at different values. Under the condition of obtaining high-quality lead/lag chaotic synchronization, the system can well realize four-channel two-way OTDM secure communication by using the advantages of flexible spin control and polarization coding and decoding of laser output, and has good two-way OTDM security communication. OTDM secure communication performance.

Of course, the embodiment of the present invention mainly uses two mutually coupled spin VCSELs to construct a two-way secure communication system. The above embodiment realizes four-channel two-way OTDM secure communication. On the basis of this embodiment, by modulating the multiplexing delay The expansion of the module and the optical fiber beam splitting modulation module can also realize other multi-channel bidirectional OTDM secure communication, such as 8 channels, 16 channels and so on.

The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features It is considered to be the range described in this specification.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the patent of the present application shall be subject to the appended claims.

Claims

A four-channel ultra-high-speed two-way OTDM security communication system is characterized in that it comprises two optical fiber generation and demultiplexing modules, two multiplexing delay modulation modules and two optical fiber beam splitting modulation modules, wherein,

Each fiber generation and demultiplexing module includes a feedback laser, a spin VCSEL, and a bidirectional fiber circulator, respectively. The polarized light generated by the feedback laser passes through the spin VCSEL and the bidirectional fiber circulator in turn to generate two paths of light waves. The light waves are respectively injected into the optical fiber beam splitting modulation module and the multiplexing delay module;

Each multiplexing delay modulation module includes a fiber polarization beam splitter, two delay multiplexing modules, a fiber polarization controller, and a fiber beam splitter respectively, and the fiber polarization beam splitter generates all the components of the wave splitting module through the fiber. The injection of one of the generated light waves generates two polarized waves from the light waves, and the two polarized waves are modulated and delayed multiplexed with four input optical signals through a delay multiplexing module respectively, and after two delay multiplexing The two light waves generated by the module respectively modulated and time-delayed are polarized by the fiber polarization controller to generate one light wave fiber. The light wave fiber generates two light waves through the fiber beam splitter. One of the light waves generated by the fiber beam splitter Injecting into the optical fiber polarization beam splitter of the optical fiber beam splitting modulation module, and injecting another light wave into the bidirectional optical fiber circulator of the optical fiber generation wave splitting module;

Each optical fiber beam splitting modulation module includes two optical fiber polarization beam splitters and two demodulation filter modules respectively, and the two optical fiber polarization beam splitters respectively generate one of the light waves generated by the wave splitting module and the complex optical fiber through the optical fiber. Using the injection of one of the light waves generated by the delay modulation module, the injected two light waves generate two polarized waves respectively, and the two polarized waves are injected into the two demodulation filter modules respectively. The filtering modules are respectively synchronously demodulated and filtered to generate four output optical signals.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 1, wherein the optical fiber generation and demultiplexing module comprises a first optical fiber generation and demultiplexing module and a second optical fiber generation and demultiplexing module, and the first optical fiber generates and demultiplexes a module. The generation and demultiplexing module includes a first feedback laser, a first polarization control circuit, a first spin VCSEL and a first bidirectional fiber circulator, and the second fiber generation and demultiplexing module includes a second feedback laser, a second polarization control circuit, The second spin VCSEL and the second bidirectional fiber circulator, the polarized light emitted by the first feedback laser is injected into the first spin VCSEL in parallel via the first polarization control circuit, and the polarized light emitted by the second feedback laser Light is injected in parallel into the second spin VCSEL via a second polarization control circuit.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 2, wherein the first feedback laser and the first polarization control circuit and between the second feedback laser and the second polarization circuit are respectively set There are first fiber isolators and second fiber isolators for unidirectional propagation of polarized light.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 1, wherein the multiplexing delay modulation module comprises a first multiplexing delay modulation module and a second multiplexing delay modulation module, the multiplexing delay modulation module The first multiplexing delay modulation module includes a first fiber polarization beam splitter, a first delay multiplexing module, a second delay multiplexing module, a first fiber polarization controller and a first fiber beam splitter; The two-multiplexing delay modulation module includes a second polarization beam splitter, a third delay multiplexing module, a fourth delay multiplexing module, a second fiber polarization controller and a second fiber beam splitter;

One of the light waves generated by the first bidirectional fiber circulator is injected into the first fiber polarization beam splitter to split into two polarized waves, and the two polarized waves are injected into the first delay multiplexing module and the second delay respectively. The multiplexing module synthesizes one optical fiber through the first optical fiber polarization controller, one optical fiber generates two optical waves through the first optical fiber beam splitter, and one of the optical waves generated by the first optical fiber beam splitter is injected into the second bidirectional optical fiber circulator;

One of the light waves generated by the second bidirectional optical fiber circulator is injected into the second optical fiber polarization beam splitter to split into two polarized waves, and the two polarized waves are respectively injected into the third delay multiplexing module and the fourth delay multiplexer. The time multiplexing module synthesizes one optical fiber through the second optical fiber polarization controller, one optical fiber generates two optical waves through the second optical fiber beam splitter, and one of the optical waves generated by the second optical fiber beam splitter Inject the first bidirectional fiber optic circulator.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 4, wherein the first delay multiplexing module, the second delay multiplexing module, the third delay multiplexing module and the fourth delay multiplexing module The time multiplexing modules respectively include a third fiber beam splitter, four modulators, four delayers and an optical multiplexer, and each of the modulators corresponds to each delayer one-to-one;

The two polarized waves injected by the first optical fiber polarization beam splitter are respectively injected into the first delay multiplexing module and the second delay multiplexing module, and are respectively passed through the first delay multiplexing module and the second delay multiplexing module. The third fiber beam splitter of the delay multiplexing module is divided into four paths of light waves, and the four paths of light waves divided by the third fiber beam splitter are modulated with the input signals of the four paths of light waves through the four modulators respectively, and the four delay devices Delay and inject into the first optical fiber polarization controller after multiplexing by the optical multiplexer;

The two polarized waves injected by the second optical fiber polarization beam splitter are respectively injected into the third delay multiplexing module and the fourth delay multiplexing module, and are respectively passed through the third delay multiplexing module and the fourth delay multiplexing module. The third fiber beam splitter of the delay multiplexing module is divided into four paths of light waves, and the four paths of light waves divided by the third fiber beam splitter are respectively modulated by four modulators and four paths of light wave input signals, and delayed by four delay devices. , and the optical multiplexer is multiplexed and then injected into the second optical fiber polarization controller.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 4, wherein the optical fiber splitting modulation module comprises a first optical fiber splitting modulation module and a second optical fiber splitting modulation module, the first optical fiber The beam splitting modulation module includes a third fiber polarization beam splitter, a fourth fiber polarization beam splitter, a first demodulation filter module and a second demodulation filter module, and the second fiber beam split modulation module includes a fifth fiber polarization splitter. a beam splitter, a sixth optical fiber polarization beam splitter, a third demodulation filter module and a fourth demodulation filter module;

The other light wave of the first optical fiber beam splitter is injected into the third optical fiber polarization beam splitter, and two polarized waves are generated by the third optical fiber polarization beam splitter. The two polarized waves are injected into the first demodulation filter module and the second demodulation filter module respectively; the other channel of the second bidirectional fiber circulator is injected into the fourth fiber polarization beam splitter, The four-fiber polarization beam splitter generates two paths of polarized waves, and the two paths of polarized waves generated by the fourth fiber polarization beam splitter are respectively injected into the first demodulation filter module and the second demodulation filter module;

Another light wave of the second optical fiber beam splitter is injected into the sixth optical fiber polarization beam splitter, and two paths of polarized waves are generated by the sixth optical fiber polarization beam splitter. The two polarized waves are injected into the third demodulation filter module and the fourth demodulation filter module respectively; the other channel of the first bidirectional optical fiber circulator is injected into the fifth optical fiber polarization beam splitter, The five-fiber polarization beam splitter generates two polarized waves, and the two polarized waves generated by the fifth fiber polarization beam splitter are respectively injected into the third demodulation filter module and the fourth demodulation filter module.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 6, wherein the first demodulation filter module, the second demodulation filter module, the third demodulation filter module and the fourth demodulation filter module respectively include a fourth fiber beam splitter, an optical time division multiplexer, four delayers, four subtraction filter modules and eight photodetectors, and the fourth fiber beam splitter corresponds to the four photodetectors, The optical time division multiplexer corresponds to four delayers and four optical detectors;

One of the polarized waves generated by the third optical fiber polarization beam splitter and one of the polarized waves generated by the fourth optical fiber polarization beam splitter pass through the optical time division multiplexer and the optical time division multiplexer of the first demodulation filter module, respectively. The demultiplexing of the second demodulation and filtering module is to convert four paths of light waves, the delay of the delayer, and the conversion of the four photodetectors into four paths of electrical signals, and another path of polarization generated by the third fiber polarization beam splitter The wave and the other polarized wave generated by the fourth fiber polarization beam splitter are respectively divided into the fourth fiber beam splitter of the first demodulation filter module and the fourth fiber beam splitter of the second demodulation filter module. The four paths of light waves and the four optical detectors are converted into four paths of electrical signals, and the four paths of electrical signals converted by the four optical detectors corresponding to the optical time division multiplexer are the same as the four paths of the electrical signals corresponding to the fourth optical fiber beam splitter. The four-way electrical signals converted by the photodetector are demodulated and filtered synchronously by four subtraction filtering modules to generate four-way output optical signals;

One of the polarized waves generated by the fifth optical fiber polarization beam splitter and one of the polarized waves generated by the sixth optical fiber polarization beam splitter pass through the optical time division multiplexer and the optical time division multiplexer of the third demodulation filter module, respectively. The demultiplexing of the fourth demodulation filter module is four-way light wave, the delay of the delay device, and the four optical detectors are converted into four-way electrical signals, and the other channel of polarization generated by the fifth optical fiber polarization beam splitter The wave and another polarized wave generated by the sixth optical fiber polarization beam splitter are respectively divided into the fourth optical fiber beam splitter of the third demodulation filtering module and the fourth optical fiber beam splitter of the fourth demodulation filtering module. The four paths of light waves and the four optical detectors are converted into four paths of electrical signals, and the four paths of electrical signals converted by the four optical detectors corresponding to the optical time division multiplexer are the same as the four paths of the electrical signals corresponding to the fourth optical fiber beam splitter. The four paths of electrical signals converted by the photodetector are respectively demodulated and filtered synchronously by four subtraction filter modules to generate four paths of output optical signals.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 1, wherein a neutral density filter is provided before and after the spin VCSEL to control the light intensity.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 2, wherein the first polarization control circuit and the second polarization control circuit include a fiber polarizer, a fiber polarization controller and a fiber depolarizer for to convert the two polarized components of polarized light.
The four-channel ultra-high-speed two-way OTDM secure communication system according to claim 1, wherein the four input optical signals are four different input optical signals.