阅读说明：本技术 基于半导体激光器网络的多路低相关激光混沌生成系统 (Multi-path low-correlation laser chaotic generation system based on semiconductor laser network ) 是由 江宁 刘世勤 赵安可 张逸群 邱昆 曹宇 于 2021-09-15 设计创作，主要内容包括：本发明公开了一种基于半导体激光器网络的并行多路低相关激光混沌生成系统,包括：N个并行的半导体激光器及产生低相关激光混沌信号的耦合光路；其中,每一路半导体激光器产生一路激光信号,然后输入至对应的耦合光路,耦合光路根据预设的邻接矩阵实现耦合光路间的互耦合,从而产生多路低相关性的、有效带宽20GHz左右的且时延标签完全抑制的激光混沌。(The invention discloses a parallel multi-path low correlation laser chaos generation system based on a semiconductor laser network, which comprises: n parallel semiconductor lasers and a coupling optical path for generating low-correlation laser chaotic signals; each semiconductor laser generates a laser signal and then inputs the laser signal to a corresponding coupling light path, and the coupling light paths realize mutual coupling among the coupling light paths according to a preset adjacent matrix, so that multi-path low-correlation laser chaos with effective bandwidth of about 20GHz and completely suppressed delay labels is generated.)

1. A parallel multi-path low correlation laser chaotic generating system based on a semiconductor laser network is characterized by comprising: n parallel semiconductor lasers and a coupling optical path for generating low correlation laser chaotic signals, wherein the serial number of the semiconductor lasers is marked as SLi, i is 1,2, …, N.

Each path of semiconductor laser generates a path of laser signal, and then the laser signal is input to a corresponding coupling light path, and the coupling light paths realize mutual coupling among the coupling light paths according to a preset adjacent matrix, so that parallel multi-path low-correlation laser chaotic signals are output.

2. A parallel multi-path low-correlation laser chaos generation system based on a semiconductor laser network is characterized in that random mutual coupling is carried out between every two semiconductor lasers with a coupling probability of 0.5, and if the semiconductor lasers SLi and SLj are mutually coupled, an adjacent matrix element A is adjacent to the matrix element A_ij＝A_jiIf there is no coupling between the semiconductor laser SLi and the semiconductor laser SLj, 1, a_ij＝A_ji0, where i ≠ 1,2, …, N, j ≠ 1,2, …, N, i ≠ j.

3. A parallel multi-path low correlation laser chaos generation system based on a semiconductor laser network is characterized in that a semiconductor laser SLi generates a path of laser signals and inputs the laser signals to a coupling optical path i; in the coupled optical path i, a%: b% coupler, the output a% part is injected into 1 XN coupler after the output intensity is adjusted by attenuator, the output end is divided into N paths with the same signal power; n paths of outputs of the 1 XN coupler are respectively and correspondingly injected into coupling light paths of the N semiconductor lasers, wherein the ith path of output is vacant; the j-th output corresponds to a coupling light path j of SLj, i is not equal to j; if adjacent to matrix coefficient A_ji＝A_ij1, the jth path of the coupling optical path i is connected with the ith path of the coupling optical path j, the output of the jth path of the coupling optical path i is injected into the ith path of the coupling optical path j, the injection intensity is adjusted by an attenuator and then injected into a% of SLj, the a% end of a b% coupler is injected into SLj, meanwhile, the output of the ith path of the coupling optical path j is injected into the jth path of the coupling optical path i, the injection intensity is adjusted by the attenuator and then injected into a% of SLi, the a% end of the b% coupler is injected into SLi, the mutual coupling between SLi and SLj is realized, and the coupling delay of SLi and different adjacent lasers is different; if A_ji＝A_ijWhen the j-th output of the coupling optical path i and the i-th output of the coupling optical path j are empty; under a mutual coupling mechanism, all lasers work in a chaotic state, and the ratio of a% of N lasers is as follows: and b% of the output of the b% coupler is output through a photoelectric detector to obtain a multi-path chaotic signal.

Technical Field

The invention belongs to the technical field of multi-path low-correlation laser chaotic sources, and particularly relates to a parallel multi-path low-correlation laser chaotic generating system based on a semiconductor laser network.

Background

The multi-path low-correlation laser chaotic source has wide application in the fields of high-speed random number generation, multi-target radar detection, ultrafast photon decision and the like. The laser chaos has broadband and noise-like characteristics, a plurality of paths of chaotic signals are used as a physical entropy source, and a plurality of paths of physical random numbers can be generated simultaneously through post-processing methods such as multi-bit quantization, time delay XOR and the like, so that the generation rate of the physical random numbers is improved; the multi-path low-correlation laser chaotic signal is used as a signal source for radar detection, so that multi-target and multi-angle high-precision detection can be realized simultaneously; in addition, the multi-path low-correlation laser chaotic source can be used for photon decision after parallel sampling, the convergence period can be shortened, and the fast and stable decision can be realized.

The external cavity feedback semiconductor laser has the advantages of simple structure, easy realization, small volume, easy integration and the like, and is a common light source for generating chaotic laser. However, in the existing research, an autocorrelation curve of a laser chaotic signal generated by a traditional external cavity feedback semiconductor laser has an obvious peak value at a feedback delay position, which is called as a delay label, and the implied periodicity can reduce the complexity of the laser chaotic signal, so that the application performance of laser chaos is limited. In the random number generation application, due to the fact that a time delay label exists in a chaotic signal, the randomness and the extraction rate of the obtained random number are limited; in radar detection application, a plurality of cross-correlation peaks exist in a cross-correlation curve of a reference signal and a received signal due to a time delay label in laser chaos, so that the position of a target is easily judged by mistake, and the accuracy of radar detection is reduced; in the application of photon decision making, the larger the time delay label is, the slower the decision convergence speed is, and the time delay label in the laser chaos can degrade the decision making performance. In addition, the single-path chaotic signal cannot realize multi-path random number generation, multi-target high-precision radar detection and faster photon decision application.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a parallel multi-path low-correlation laser chaotic generating system based on a semiconductor laser network, which is used for generating multi-path low-correlation chaotic signals, low correlation exists among the multi-path chaotic signals, and time delay labels of all the chaotic signals are completely inhibited.

In order to achieve the above object, the present invention provides a parallel multi-path low correlation laser chaos generation system based on a semiconductor laser network, which is characterized by comprising: the device comprises N parallel semiconductor lasers and a coupling optical path for generating low-correlation laser chaotic signals, wherein the serial number of the semiconductor lasers is marked as SLi, i is 1,2, …, N;

each path of semiconductor laser generates a path of laser signal, and then the laser signal is input to a corresponding coupling light path, and the coupling light paths realize mutual coupling among the coupling light paths according to a preset adjacent matrix, so that parallel multi-path low-correlation laser chaotic signals are output.

Further, the semiconductor lasers are mutually coupled at random with a coupling probability of 0.5 between each two lasers, and if the semiconductor laser SLi and the semiconductor laser SLj are mutually coupled, the adjacent matrix element A is_ij＝A_jiIf there is no coupling between the semiconductor laser SLi and the semiconductor laser SLj, 1, a_ij＝A_ji0, where i ≠ 1,2, …, N, j ≠ 1,2, …, N, i ≠ j.

Furthermore, the semiconductor laser unit SLi generates a laser signal and inputs the laser signal to the coupling optical path i; in the coupled optical path i, a%: b% coupler, the output a% part is injected into 1 XN coupler after the output intensity is adjusted by attenuator, the output end is divided into N paths with the same signal power; n paths of outputs of the 1 XN coupler are respectively and correspondingly injected into coupling light paths of the N semiconductor lasers, wherein the ith path of output is vacant; the jth output corresponds to the ith path of the coupling optical path j of SLj, i is not equal to j; if adjacent to matrix coefficient A_ji＝A_ij1, the jth path of the coupling optical path i is connected with the ith path of the coupling optical path j, the jth output of the coupling optical path i is injected into the ith path of the coupling optical path j, the injection intensity is adjusted by an attenuator and then injected into a% of SLj, the a% end of a b% coupler is injected into SLj, meanwhile, the ith output of the coupling optical path j is injected into the jth path of the coupling optical path i, the injection intensity is adjusted by the attenuator and then injected into a% of SLi, the a% end of the b% coupler is injected into SLi, so that the mutual coupling between SLi and SLj is realized, and the coupling delay time of SLi and different adjacent lasers is delayed and is equal to that of SLj and SLjDifferent; if A_ji＝A_ijWhen the j-th output of the coupling optical path i and the i-th output of the coupling optical path j are empty; under a mutual coupling mechanism, all lasers work in a chaotic state, and the ratio of a% of N lasers is as follows: and b% of the output of the b% coupler is output through a photoelectric detector to obtain a multi-path chaotic signal.

The invention aims to realize the following steps:

the invention relates to a parallel multi-path low correlation laser chaos generation system based on a semiconductor laser network, which comprises: n parallel semiconductor lasers and a coupling optical path for generating low-correlation laser chaotic signals; each semiconductor laser generates a laser signal and then inputs the laser signal to a corresponding coupling light path, and the coupling light paths realize mutual coupling among the coupling light paths according to a preset adjacent matrix, so that multi-path low-correlation laser chaos with effective bandwidth of about 20GHz and completely suppressed delay labels is generated.

Meanwhile, the parallel multi-path low-correlation laser chaotic generating system based on the semiconductor laser network also has the following beneficial effects:

(1) the invention can generate multi-path chaotic signals, the effective bandwidth range is wide, and the correlation of any two paths of chaotic signals is lower than 0.1;

(2) the invention adopts an asymmetric coupling semiconductor laser network structure, and each coupling edge has different coupling delays, so that the asymmetric mutual coupling structure and the heterogeneous delay coupling can ensure that the generated multi-path chaotic signals have low correlation, and simultaneously realize the inhibition of multi-path chaotic signal delay labels;

(3) the method is used as an entropy source for random number generation, can generate multiple paths of physical random numbers at the same time, and greatly improves the randomness and the generation rate of the random numbers. The multi-path chaotic signal with low correlation and suppressed time delay label is applied to a radar system, so that the target detection with multiple targets, low misjudgment and high precision can be realized;

(4) sampling and quantifying the multi-path low-correlation chaotic signal suppressed by the time delay label, and using the obtained binary sequence as a photon decision, so that the convergence period can be shortened, the convergence speed is improved, and the ultra-fast photon decision is realized;

drawings

FIG. 1 is a schematic diagram of a parallel multi-path low correlation laser chaotic generating system based on a semiconductor laser network according to the present invention; wherein (a) is a first principle architecture diagram of the system; (b) is a structure diagram of a specific implementation mode of the system;

FIG. 2 is a multi-path broadband chaotic signal waveform and power spectrum diagram;

FIG. 3 is a graph of low correlation effect;

fig. 4 is a time-delay label suppression effect diagram.

Detailed Description

The following description of the embodiments of the present invention is provided in order to better understand the present invention for those skilled in the art with reference to the accompanying drawings. It is to be expressly noted that in the following description, a detailed description of known functions and designs will be omitted when it may obscure the subject matter of the present invention.

Examples

Fig. 1 is a schematic diagram of a parallel multi-path low correlation laser chaos generation system based on a semiconductor laser network.

In this embodiment, as shown in fig. 1, the parallel multi-path low correlation laser chaotic generating system based on a semiconductor laser network of the present invention includes: the optical coupler comprises N parallel semiconductor lasers and a coupling optical path for generating low-correlation laser chaotic signals, wherein the serial number of the semiconductor lasers is marked as SLi, i is 1,2, …, and N is a positive integer greater than 2;

each path of semiconductor laser generates a path of laser signal, and then the laser signal is input to a corresponding coupling light path, and the coupling light paths realize mutual coupling among the coupling light paths according to the coupling condition described by the preset adjacent matrix, so that parallel multi-path low-correlation laser chaotic signals are output.

The coupling condition described by the preset adjacency matrix is mainly embodied by the element values of the adjacency matrix, in the laser network, any two lasers are randomly coupled with each other with the coupling probability of 0.5, and the almost coupling and decoupling between any two lasersThe ratio is 50% each, and if SLi and SLj are coupled to each other, the adjacent matrix element A is_ij＝A_jiIf there is no coupling between SLi and SLj, a is 1_ij＝A_ji0, where i is 1,2, …, N, j is 1,2, …, N, and the coupling matrix is shown in equation (1) below; in addition, it is necessary to ensure that the coupling of all laser nodes in the resulting random coupling network is asymmetric. Whether the laser nodes are symmetrically coupled can be judged through the adjacency matrix, the row vector of the ith row of the adjacency matrix represents the coupling item of the SLi, when the row vectors corresponding to the coupling items of the two lasers are different, the two lasers can be considered to be asymmetrically coupled, and otherwise, the two lasers are symmetrically coupled. When the coupling terms of any two laser nodes in the laser network are different, all the lasers are asymmetrically coupled.

In this embodiment, the coupling strength σ of each coupling edge in the semiconductor laser network is the same, and if any two rows of elements are different, all the lasers are asymmetrically coupled, and the asymmetrically coupled semiconductor laser network is favorable for chaotic generation of low-correlation multi-path lasers.

With the preset adjacency matrix, after a specific semiconductor laser network is designed, laser nodes are interconnected according to the coupling condition between the nodes described by the adjacency matrix, and a light path is built. As shown in fig. 1 (a), SL1 generates a laser signal, and the laser signal is mutually coupled with other lasers through an optical path 1 to form a laser chaos, when A1i is Ai1 is 1, i is 2,3, …, N, the output of SL1 passes through the optical path 1 and then is injected into the optical path i corresponding to SLi, and then is injected into SLi, and the laser signal generated by SLi passes through the optical path i and then is injected into the optical path 1, and further is injected into SL 1. When A1i is 0 in Ai1, the optical path 1 and the optical path i of SL1 and SLi are not coupled to each other. The chaotic signal generated by the SL1 is output from the optical path 1. In the same way, the optical path coupling of other lasers is similar, but the coupling optical path lengths of different lasers are different, and the coupling time delay is different. And outputting the rest N-1 paths of laser chaos from the corresponding light paths of other lasers to finally obtain parallel N paths of low-correlation chaotic signals.

The optical path connections between the specific devices of the network are shown in fig. 1 (b). By taking one of the lasers SL1 as an example to illustrate the optical path coupling mechanism, the output laser signal of SL1 passes through an a%: b% ═ 80%: the 20% coupler outputs a% part, adjusts the output intensity through the attenuator, injects into 1 XN coupler, its output end divides into N routes with the same signal power, N routes of output inject into N lasers correspondingly respectively. And other lasers also obtain N output ports with the same power after passing through similar optical paths. The 1 st output of the 1 xn coupler of SL1 is left empty from the feedback. The i-th output (i ≠ 1) of the 1 × N coupler of SL1 corresponds to the coupling with the 1 × N coupler output of SLi, if the adjacent matrix coefficient A1i ═ Ai1 ═ 1, i ═ 2,3, …, N, (SL1 is inter-coupled with SLi), the i-th path of the 1 × N coupler of SL1 is connected to the 1 st path of the 1 × N coupler of SLi, the i-th output of the 1 × N coupler of SL1 is injected into the 1 st path of the 1 × N coupler of SLi, the injection intensity is adjusted by an attenuator and then injected into the a% of SLi, the a% end of b% coupler and then injected into SLi, at the same time, the N path of the 1 × N coupler of SL1 can also be used as the input end of the injection of other laser into SL1, the 1 × N output of the 1 × N coupler of SLi is injected into the 1 × N coupler of SL1, the input intensity of the 1 × N coupler of SL1 is adjusted by the attenuator and then injected into the input end of SL1 a% of the attenuator, then injected into SL1 to achieve the purpose of mutual coupling of SL1 and SLi, and the coupling delay of SL1 and different adjacent lasers is different; if A1i ═ Ai1 ═ 0(SL1 is not mutually coupled to SLi), the ith output of the 1 × N coupler of SL1 and the 1 st output of the 1 × N coupler of SLi are left empty. Similarly, the output of the ith of the 1 × N coupler of the laser SLi (i ═ 2,3, …, N) is empty (the other outputs of the 1 × N coupler of SLi are mutually coupled with the outputs of the 1 × N couplers of other lasers through the optical path according to the adjacent matrix elements.

Each semiconductor laser in the laser network provided by the invention receives the injection of output chaotic signals from other lasers; when the injection time delays are different, the injected light from different paths is equivalent to a plurality of different external cavity modes, and the injected light from different paths has a nonlinear relation, so that each laser receives nonlinear injection, and the time delay label of the chaotic signal is restrained.

Examples of the invention

Taking a heterogeneous delay coupling network composed of 10 asymmetric coupling lasers as an example, the correlation and the delay label suppression effect of the multi-path chaotic signals generated simultaneously are discussed. The coupling matrix of the semiconductor laser network is shown as a formula (2), the row injection items corresponding to any two semiconductor lasers in the coupling matrix are different, 23 coupling edges are shared, and the coupling strength is 40ns^-1. The coupling delays of any two edges in the semiconductor laser network are different, and all the coupling delays are subjected to normal distribution with the mean value of 5ns and the variance of 1 ns.

Fig. 2 shows waveforms and power spectrums of output chaotic signals of 10 semiconductor lasers. The effective Bandwidth (BW) is defined as the range between the dc frequency component and the frequency that contains 80% of the total energy in the spectrum. Under the influence of relaxation oscillation, the chaotic effective bandwidth of laser generated by an external optical feedback semiconductor laser is only several GHz generally. By the scheme provided by the invention, the semiconductor laser network can output multi-path chaotic signals, and the effective bandwidth of the chaotic signals is 19.84 GHz-20.91 GHz. In addition, the effective bandwidth of the multi-path chaotic signals can be further improved by increasing the coupling strength between the semiconductor lasers.

Fig. 3 shows the implementation of low correlation among multiple chaotic signals, and a cross-correlation function (CCF) is adopted to calculate the correlation among multiple chaotic signals generated by an asymmetric coupled semiconductor laser network under heterogeneous delay coupling. Due to asymmetric coupling, the correlation of two chaotic signals generated by any two lasers is lower than 0.1, and the generation of a multi-path chaotic signal with low correlation is realized.

Fig. 4 shows the implementation of multi-path chaotic signal delay label suppression, and we use an autocorrelation function (ACF) to observe the delay characteristics of the chaotic signal. Under the action of heterogeneous delay coupling, no obvious correlation peak is observed in the range of the autocorrelation curve [ -10ns,10ns ] of all the generated chaotic signals, which shows that the delay tags introduced by mutual coupling in the chaotic signals are completely inhibited.

In summary, the multi-path low correlation laser chaos generation scheme provided by the invention has the following benefits: (1) can generate multi-path chaotic signals, and the effective bandwidth of the multi-path chaotic signals is about 20 GHz; (2) the correlation of any two chaotic signals is lower than 0.1; (3) all the time delay labels of the chaotic signals are completely suppressed. Therefore, the entropy source is used as an entropy source for random number generation, and multiple paths of physical random numbers can be generated simultaneously, so that the randomness and the generation rate of the random numbers are greatly improved. The multi-path chaotic signal with low correlation and suppressed time delay label is applied to a radar system, and target detection with multiple targets, low misjudgment and high precision can be realized. In addition, sampling quantification is carried out on the multi-path low-correlation chaotic signals with suppressed time delay labels, and the obtained binary sequence is used for photon decision making, so that the convergence period of the chaotic signal can be shortened, the convergence speed is increased, and the ultra-fast photon decision making is realized.

Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, and various changes may be made apparent to those skilled in the art as long as they are within the spirit and scope of the present invention as defined and defined by the appended claims, and all matters of the invention which utilize the inventive concepts are protected.