全光采样光性能监测关键技术研究

发布时间：2018-03-12 16:59

本文选题：非线性光采样　切入点：线性光采样　出处：《北京理工大学》2014年博士论文　论文类型：学位论文

【摘要】：光纤通信正朝着超大容量、超高速和超长距离的方向发展，系统越来越复杂，因而对光信号性能进行实时监测以确保光网络安全可靠运行显得尤为重要。传统的基于电采样的监测技术受限于电子瓶颈，难以对高速信号进行分析。而全光采样技术则克服了这一缺点，并做到速率和调制格式透明，具有广阔的应用前景。本文针对基于全光采样的光性能监测若干关键技术进行了研究，主要内容包括：（1）研究了软件同步采样技术，采样脉冲重复频率无需满足奈奎斯特采样定律，降低了后续电处理器件的带宽需求。研究表明，当降频余数为零或者倒数为有限位有理数时，眼图恢复效果差，称为软件同步算法的固有缺陷。分析并给出了软件同步采样对脉冲幅度抖动、定时抖动和宽度的要求，为采样脉冲源的设计和制作提供了指导。（2）对非线性偏振旋转锁模光纤激光器进行了数学建模，利用琼斯矩阵描述偏振控制器，利用Giles模型描述掺铒光纤。与已有模型相比，该模型与实际系统相符，具有各个参数物理意义清晰的优点。通过仿真产生了半幅全宽度为622fs的脉冲，光谱宽度4.8nm，有很强的边带产生，是典型的孤子态。同时，利用该模型研究了偏振控制器方位角以及泵浦功率对脉冲的影响，结果表明随机双折射将使方位角可调谐范围减小，泵浦功率过高或者过低都不能产生脉冲，脉冲平均功率与泵浦功率成正比。搭建了锁模激光器，，产生了重复频率为29.54MHz的采样脉冲，中心波长1575.91nm，脉冲宽度630fs。（3）研究了周期极化铌酸锂波导中的倍频效应与和频效应，设计了基于和频效应的采样光路。利用带通滤波器对采样脉冲进行滤波，然后进入掺铒光纤放大器。放大后的采样脉冲峰值功率与未滤波直接放大的结果相比，提高了10dB。讨论了带通滤波器带宽对和频光、倍频光的影响，指出带宽存在最佳值0.4nm，带宽过大或者过小都将使采样信号的眼图变差。制作了光采样示波器样机并进行测试，可以测量12Gbit/s以上强度调制信号的眼图，灵敏度-3dBm，对信号速率、光信噪比、色散等特性的监测结果与商用高速电采样示波器一致。（4）为实现光采样示波器样机的自动测量，提出对采样脉冲的波长进行遍历，以采样信号标准差最大时对应的波长作为和频效应准相位匹配波长。数值仿真和实验结果都表明采样信号标准差与和频光功率成正比，与倍频光功率无关，证实了该方法的可行性。另外，设计了偏振分集结构，实现偏振无关的采样，和频光偏振相关性为1.67dB。利用宽光谱采样脉冲，实现了对1530~1565nm波段信号光的采样。（5）针对传统的软件同步采样不能获取待采样信号速率的问题，提出了多频采样法，即利用两个重复频率不同的采样脉冲进行采样，可从采样信号中提取出真实速率。制作了腔长可调谐的采样脉冲源，产生重复频率为20.26677MHz和20.22900MHz的锁模脉冲，对100MHz正弦信号光的速率进行恢复，结果为102.22MHz。另外，首次研究了该算法存在的两个盲区，提出增加一次采样以消除盲区的方法，给出了理论推导以及仿真和实验证明。（6）对线性采样技术进行了初步研究，推导了线性采样信号的表达式，给出了消除频率偏移、相位偏移和相位噪声的方法。利用光学混频器、平衡探测器设计了线性采样实验系统，成功地恢复出连续光的波形和12Gbit/s强度调制信号光的眼图，得到了1MHz2PSK信号的星座图。
[Abstract]:Optical fiber communication is towards large capacity, high speed and long distance in the direction of development, the system becomes more and more complex, so it is important to ensure the safe and reliable operation of optical network is the real-time monitoring of optical signal performance. Electric sampling monitoring technology is limited by the electronic bottleneck based on the traditional, it is difficult for high-speed signal analysis and all-optical sampling. The technology overcomes this shortcoming, and do the rate and modulation format transparency, and has broad application prospects.
In this paper, some key technologies for optical performance monitoring based on all optical sampling are studied. The main contents are as follows:
(1) the software synchronous sampling technique, sampling pulse repetition frequency without the need to satisfy the Nyquist sampling theorem, reduces the bandwidth requirements of subsequent electric processing device. The results show that when the reduced frequency of the remainder is zero or inverse limit rational number, eye recovery effect, said the inherent defects of synchronization algorithm for software analysis. And gives the software synchronous sampling of pulse amplitude jitter, timing jitter and width requirements, provide guidance for the design and manufacture of sampling pulse source.
(2) the nonlinear polarization rotation mode-locked fiber laser is studied by mathematical modeling, the Jones matrix polarization controller, Giles model is used to describe the erbium-doped fiber. Compared with the existing models, this model is consistent with the actual system, has the advantages of clear physical meaning of each parameter. The simulation produced a half full width of 622fs pulse, spectrum width of 4.8nm, there is a strong side, is a typical soliton state. At the same time, the azimuth angle of polarization controller and the pump power of the pulse effect by using the model, results show that the random birefringence will make the azimuth tuning range decreases, the pump power is too high or too low can produce pulse, pulse the average power and pump power is proportional to. To build a mode-locked laser, the pulse repetition frequency sampling 29.54MHz, the central wavelength of 1575.91nm, pulse width of 630fs.
(3) the frequency doubling effect of periodically poled lithium niobate waveguide and the frequency and effect, designed based on optical sampling and frequency effect. By using the band-pass filter to filter the sampling pulse, and then enter the erbium-doped fiber amplifier. Compared with the direct amplification of the sampling pulse peak power and filtering results, improve the 10dB. discusses the bandwidth of the bandpass filter and the frequency of light, affecting the frequency of light, pointed out that there exists an optimum value of 0.4nm bandwidth, the bandwidth is too large or too small will make the eye diagram of sampling signal variation. The optical sampling oscilloscope prototype manufacturing and testing, can the eye diagram above 12Gbit/s intensity modulation signal measurement sensitivity of -3dBm on. Signal rate, optical signal-to-noise ratio, the monitoring results of dispersion and high speed electric commercial sampling oscilloscope.
(4) for the realization of automatic measurement of optical sampling oscilloscope prototype, proposed to traverse the sampling pulse wavelength, with sampling signal standard deviation corresponds to the maximum wavelength and frequency effect as quasi phase matching wavelength. The numerical simulation and experimental results show that the standard deviation of the sampling signal and the frequency of light power is proportional to the frequency of light has nothing to do with power, confirmed the feasibility of this method. In addition, the design of polarization diversity sampling to achieve polarization independent frequency, and polarization correlation for 1.67dB. by using wide spectrum sampling pulse, the optical sampling of 1530~1565nm band signal.
(5) the traditional software synchronous sampling can not get to be sampled signal rate problems, proposed a multi frequency sampling method, different sampling pulse sampling with two repetition frequency, can be extracted from the real rate of sampling signal. Making the cavity length tunable sampling pulse source, generating repetition frequency 20.26677MHz and 20.22900MHz mode-locked pulse, the rate of 100MHz sinusoidal signal light of the recovery, the 102.22MHz. also studied for the first time the two blind algorithm, proposed an increase in sampling to eliminate the blind method, the theoretical derivation and simulation and experimental results.
(6) of the linear sampling technique were studied. The expressions of linear sampling signal is deduced and given the elimination of frequency offset, phase offset and phase noise. Using optical mixer, balance detector design linear sampling experiment system successfully recovered from the eye diagram of continuous light intensity modulation waveform and 12Gbit/s signal light. The 1MHz2PSK signal constellation.

【学位授予单位】：北京理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.11

【参考文献】