偏振改变的FBG光反馈下1550nm VCSELs混沌信号的延时特征和带宽研究

发布时间：2018-09-08 10:48

【摘要】：近年来,由于光混沌在安全保密通信、混沌雷达、随机数的产生等方面具有重大的应用价值受到广泛关注。尽管外腔反馈半导体激光器是常见的光混沌保密通信源,但是这种常见的光混沌保密通信源在获得高维的混沌输出同时相应地引入了延时特征(TDS)。目前已提出许多关于这个问题的解决方案,但大部分的技术都是针对边发射激光器(EELs)的。根据发射波长划分,1550nm垂直腔表面发射激光器(VCSELs)作为长波长激光器,不仅具有普通VCSELs优于传统EELs的诸多地方,而且在城际光互连、高速光网络等方面具有重要的应用价值。随着混沌保密通信技术的不断发展,能够实现多向通信方式的混沌同步网络相继被提出,这些混沌网络大都基于常规边发射激光器(EELs),但由于混沌载波带宽的限制其信号传输能力都在10GHz以内,为了顺应现代大容量通信的需求,能够实现更高通信容量的混沌同步网络有待提出。本文通过外腔偏振旋转的光纤布拉格光栅(FBG)光反馈引入混沌,提出了一种新的抑制1550nmVCSEL混沌信号延时特征(TDS)的方法。同时采用FBG偏振旋转光反馈,对多个1550nm VCSELs组成的同步通信网络进行了研究。本文采用自旋反转模型进行速率方程数值模拟,对混沌信号的输出,采用自相关函数(SF)和排列熵方法(PE)来考察相关系统混沌信号的TDS。在1550nmVCSEL混沌同步网络中,为了确保混沌的有效性,采用了有效带宽计算方法,并通过互相关函数,计算了相关激光器之间的同步系数。研究结果表明：在合适的反馈条件下,偏振旋转光反馈的VCSEL系统(VPFBGF-VCSELs)能有效地抑制混沌输出的TDS。这种TDS的抑制能够优于传统反馈方式下的TDS。另一方面,偏振旋转光反馈下的1550nm VCSEL混沌同步网络中,通过FBG偏振旋转光反馈,驱动激光器(D-VCSEL)的TDS得到抑制。偏振分解的响应激光器(R-VCSEL)的两个偏振分量有效带宽得到了较大提高,在较大的参数范围内,R-VCSEL两个正交方向的输出混沌带宽高达20GHz。各R-VCSEL相应分量之间的完全同步系数接近1,即实现了宽带同步的混沌载波输出。本文的研究结果为实现安全性能较高且容量较大的光纤通信网络提供了相关的理论指导。
[Abstract]:In recent years, optical chaos has attracted wide attention because of its great application value in secure communication, chaotic radar, random number generation and so on. Although the external cavity feedback semiconductor laser is a common optical chaotic secure communication source, this common optical chaotic secure communication source obtains high dimensional chaotic output and introduces the delay characteristic (TDS). Accordingly. Many solutions to this problem have been proposed, but most of the techniques are aimed at edge-emitting lasers (EELs). According to the wavelength division of 1550nm vertical cavity surface emitting laser (VCSELs) as a long wavelength laser, it not only has many advantages over traditional EELs, but also has important application value in intercity optical interconnection and high-speed optical network. With the development of chaotic secure communication technology, chaotic synchronization network which can realize multi-direction communication has been put forward one after another. Most of these chaotic networks are based on conventional edge-emitting lasers (EELs),). However, due to the limitation of chaotic carrier bandwidth, their signal transmission capability is within 10GHz. Chaotic synchronization networks with higher communication capacity need to be proposed. In this paper, a new method to suppress the delay characteristic (TDS) of 1550nmVCSEL chaotic signal is proposed by introducing chaos into the optical feedback of fiber Bragg grating (FBG) with polarization rotation of external cavity. At the same time, the synchronous communication network composed of multiple 1550nm VCSELs is studied by using FBG polarization rotation optical feedback. In this paper, the spin inversion model is used to simulate the rate equation. The output of chaotic signal is simulated. The autocorrelation function (SF) and permutation entropy method (PE) are used to investigate the TDS. of chaotic signal of correlation system. In 1550nmVCSEL chaotic synchronization network, in order to ensure the validity of chaos, the effective bandwidth calculation method is adopted, and the synchronization coefficient between correlated lasers is calculated by cross-correlation function. The results show that the polarization-rotated optical feedback VCSEL system (VPFBGF-VCSELs) can effectively suppress the TDS. of chaotic output under suitable feedback conditions. The inhibition of TDS is superior to that of TDS. in traditional feedback mode. On the other hand, in the 1550nm VCSEL chaotic synchronization network with polarization rotation optical feedback, the TDS of the laser (D-VCSEL) driven by FBG polarization rotation optical feedback is suppressed. The effective bandwidth of two polarization components of the polarization-decomposed response laser (R-VCSEL) is greatly improved, and the output chaotic bandwidth of R-VCSEL in two orthogonal directions is up to 20 GHz in a large range of parameters. The complete synchronization coefficient between the corresponding components of R-VCSEL is close to 1, that is, the chaotic carrier output of wideband synchronization is realized. The results of this paper provide relevant theoretical guidance for the realization of high security and large capacity optical fiber communication networks.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248

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