面向新型调制格式的全光多信道并行码型转换及再生的研究

发布时间：2018-06-02 03:07

本文选题：码型转换 + 信号再生　；参考：《华中科技大学》2014年博士论文

【摘要】：随着人们对信息需求的快速增长,现代光传输网络正朝着超高速、超大容量和超长距离传输的方向发展。新型调制格式信号由于具有高频谱效率和较强的色散和非线性抗性,已经被广泛应用在传输网络中来进一步提高单个信道信号的比特速率和传输距离。各种复用技术也已经被广泛应用在传输网络中来进一步地提高信道数,从而增大传输容量。另一方面,为了确保每个网络中能够长距离地传输最合适的码型信号,网络节点必须具备全光码型转换和信号再生的功能。所以,各种复用方式的新型调制格式信号的全光并行码型转换和再生的研究对于光通信网络的意义重大。本论文在国家973计划和国家自然科学基金项目的资助下,理论模拟研究了波分复用(WDM)信号以及偏振复用(PDM)信号在半导体光放大器(SOA)中并行信号处理时引入的串扰情况,并分析了减小并行信号处理过程中引入的串扰的方法。在此基础上利用SOA中的交叉相位调制(XPM)效应和增益饱和效应实现了WDM和PDM的新型调制格式信号的全光并行低串扰码型转换和信号再生。概括全文,主要研究成果和学术贡献有如下几个方面： (1)总结了偏振光的基本理论知识和几种描述光偏振态的方法,归纳了偏振复用和解复用的方法。在此基础上分析了偏振复用信号解复用时的串扰情况,为后面说明PDM信号并行处理过程中的串扰问题打下基础。详细分析了两种相位调制格式信号的调制产生和解调的方法,并比较说明了不同信号的特点。分析了SOA中的多种非线性效应。 (2)利用量子阱SOA模型模拟了不同情况下非归零(NRZ)到归零(RZ)信号码型转换的效果和串扰情况,解释了转换过程中减小串扰的机理和方法,用实验实现了的低串扰的多信道NRZ开关键控(OOK)到RZ-OOK信号以及多信道NRZ正交相移键控(QPSK)到RZ-QPSK信号的并行码型转换。从理论上解释了多信道RZ-QPSK到NRZ-QPSK信号码型转换的原理,并模拟了不同占空比的多信道RZ-QPSK到NRZ-QPSK信号转换的过程,分析了窄带滤波器对转换后信号幅度抖动的影响,最后用实验实现了多信道RZ-QPSK信号到NRZ-QPSK信号的并行码型转换。 (3)利用SOA模型模拟了信号经过SOA后经纬度的变化,直观地说明了SOA中的偏振旋转效应。分析了两个偏振态正交的信号在不同的泵浦光功率下通过不同偏振相关增益的SOA后的偏振正交性的变化情况,从模拟结果中得出减小偏振态正交性变化量的方法,归纳出了减小PDM信号并行处理过程中引入的串扰的方法,并用实验验证了模拟的结果。在此基础上,利用单个SOA和延时干涉仪(DI)实现了总速率为800Gb/s的WDM-PDM-NRZ-QPSK信号到WDM-PDM-RZ-QPSK信号的全光并行低串扰的码型转换。 (4)利用SOA中的增益饱和效应实现了偏振复用的RZ二进制相移键控(BPSK)信号的并行幅度再生,通过优化信号的入射偏振态减小了并行幅度再生过程中引入的信道间串扰,并研究了幅度再生过程中减小自相位调制(SPM)效应引入相位噪声的方法。接着利用两个串联的SOA和DI实现了NRZ-BPSK信号的幅度再生。 (5)利用SOA中的XPM效应,实现了NRZ-OOK信号到NRZ-BPSK信号的码型转换。利用检偏器对信号偏振态的处理减小了转换过程中交叉增益调制(XGM)效应引入的幅度抖动,得到了幅度均衡的NRZ-BPSK信号。在码型转换的过程中,同时还实现了高消光比的波长转换功能。
[Abstract]:With the rapid growth of information demand, modern optical transmission network is developing towards ultra high speed, super large capacity and ultra long distance transmission. The new modulation signal has been widely used in transmission network to further improve single channel signal because of its high frequency spectrum efficiency and strong dispersion and nonlinear resistance. Bit rate and transmission distance. Various multiplexing techniques have also been widely used in transmission networks to further increase the number of channels, thereby increasing the transmission capacity. On the other hand, in order to ensure that the most suitable code type signals can be transmitted for a long distance in each network, the network node must have the function of all optical code conversion and signal regeneration. Therefore, the research of all-optical parallel code conversion and regeneration of various modulation formats of multiplexed signals is of great significance to optical communication networks.
Under the support of the national 973 Plan and the National Natural Science Foundation, this thesis studies the crosstalk situation introduced in the parallel signal processing of the wavelength division multiplexing (WDM) signal and the polarization multiplexing (PDM) signal in the semiconductor optical amplifier (SOA), and analyzes the method of reducing the crosstalk introduced in the process of parallel signal processing. On the basis of the cross phase modulation (XPM) effect and gain saturation effect in SOA, all optical parallel low crosstalk code conversion and signal regeneration of the new modulation format signals of WDM and PDM are realized. The main research results and academic contributions are summarized as follows:
(1) the basic theoretical knowledge of polarized light and several methods describing polarization state are summarized, and polarization multiplexing and reusing methods are summed up. On this basis, the crosstalk situation of polarization multiplexing signals in demultiplexing is analyzed, and the crosstalk problem in the parallel processing of PDM signals is explained. Two phase modulation is analyzed in detail. The modulation generation and demodulation methods of format signals are compared, and the characteristics of different signals are compared. Several nonlinear effects in SOA are analyzed.
(2) using the quantum well SOA model to simulate the effect and crosstalk of non return zero (NRZ) to zero (RZ) signal conversion in different cases, the mechanism and method of reducing crosstalk in the process of conversion are explained, and the low crosstalk of multichannel NRZ switch keying (OOK) to RZ-OOK signal and multichannel NRZ quadrature phase shift keying (QPSK) to R in the process of experiment are realized. The parallel code conversion of Z-QPSK signals is used to explain the principle of multichannel RZ-QPSK to NRZ-QPSK signal conversion in theory, and the process of multichannel RZ-QPSK to NRZ-QPSK signal conversion with different duty ratio is simulated, and the effect of the narrowband filter on the amplitude jitter of the signal after the conversion is analyzed. Finally, the multichannel RZ-QPSK signal is realized by experiment. The parallel code conversion to the NRZ-QPSK signal.
(3) using the SOA model to simulate the change of the latitude and longitude after the signal after SOA, the polarization rotation effect in SOA is clearly illustrated. The polarization orthogonality of the two orthogonal signals with different polarization correlation gain under different pump light power is analyzed, and the reduction of polarization state is obtained from the simulation results. In the method of sexual variation, the method of reducing the crosstalk introduced in the parallel processing of PDM signals is summed up and the results of the simulation are verified by experiments. On this basis, a single SOA and delay interferometer (DI) is used to realize the code conversion of all optical parallel low crosstalk of the WDM-PDM-NRZ-QPSK signal with a total rate of 800Gb/s to the WDM-PDM-RZ-QPSK signal. Change.
(4) using the gain saturation effect in SOA, the parallel amplitude regeneration of the polarization multiplexed RZ binary phase shift keying (BPSK) signal is realized. By optimizing the incident polarization of the signal, the inter channel crosstalk introduced in the process of parallel amplitude regeneration is reduced, and the phase noise reduction by reducing the self phase modulation (SPM) effect in the amplitude regeneration process is studied. Then the amplitude regeneration of NRZ-BPSK signal is realized by using two series of SOA and DI.
(5) using the XPM effect in SOA, the code conversion of the NRZ-OOK signal to the NRZ-BPSK signal is realized. The amplitude jitter introduced by the cross gain modulation (XGM) effect in the conversion process is reduced by the detection of the polarization state of the signal, and the amplitude equalizable NRZ-BPSK signal is obtained. The high extinction ratio is also realized in the process of code conversion. The wavelength conversion function.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.1

【参考文献】