光学频率梳生成及其在WDM系统中应用研究

发布时间：2018-11-25 10:27

【摘要】：融合微波无线通信和光纤通信技术优势的微波光子学,可以实现微波信号的光学生成、处理、控制和传输,在下一代宽带无线通信和军事通信领域具有重要的应用前景。光学频率梳生成是微波光子学的关键技术之一,如何产生载波数目多、谱线间隔大、带外抑制比高、平坦度好以及稳定性高的光学频率梳是目前的研究热点。本文重点关注基于电光调制器的光学频率梳生成技术,并将其应用在WDM系统中。本文在分析电光调制器的理论基础上,提出了两种基于强度调制器IM的新型光学频率梳生成方案。方案一基于两个级联的马赫曾德尔强度调制器,通过设置射频信号幅值和直流偏置电压,实现3、5、9、15和25线的可调光学频率梳。方案二基于单个马赫曾德尔强度调制器调制双音信号的结构,通过设置双音信号的幅值、频率和初始相位,并调节合适的直流偏置电压,实现单个IM产生9线平坦光学频率梳。分析和讨论了调制指数、直流偏置电压和初始相位等因素对这两种方案的光学频率梳平坦度的影响。鉴于光学频率梳的带宽受限于调制器的工作带宽,研究并提出两种扩展光学频率梳频谱的方案。方案一利用马赫曾德尔强度调制器工作点不同,产生奇数阶或偶数阶光边带的原理,实现谱线间隔的扩展,最终产生了15线和20线光学频率梳。方案二设置双平行马赫曾德尔调制器DPMZM的射频信号幅值和直流工作点,利用光载波抵消的思想,实现50线宽带光学频率梳的生成。分析和讨论了调制指数与所提方案光学频率梳性能的关系。利用VPI仿真软件和实际实验对上述方案进行了验证。最后,基于单个DPMZM产生5线光学频率梳作为光源,构建点到点WDM通信系统,利用VPI仿真实现单波10Gb/s数字信息经30千米标准单模光纤传输后,系统误码率BER较小。
[Abstract]:Microwave photonics, which combines the advantages of microwave wireless communication and optical fiber communication, can realize the optical generation, processing, control and transmission of microwave signal. It has an important application prospect in the field of next generation broadband wireless communication and military communication. Optical frequency comb generation is one of the key techniques in microwave photonics. How to generate a large number of carriers, large spectral line spacing, high out-of-band suppression ratio, good flatness and high stability of optical frequency comb is a hot topic at present. This paper focuses on the optical frequency comb generation technology based on electro-optic modulator and its application in WDM system. Based on the analysis of the theory of electro-optic modulator, two novel optical frequency comb generation schemes based on intensity modulator (IM) are proposed in this paper. Scheme one is based on two cascaded Mach Zendel intensity modulators. By setting the amplitude of RF signal and DC bias voltage, the adjustable optical frequency comb with 3 / 5 / 9 / 15 and 25 lines is realized. The second scheme is based on the structure of a single Mach Zendel intensity modulator to modulate the dual-tone signal, by setting the amplitude, frequency and initial phase of the dual-tone signal, and adjusting the appropriate DC bias voltage. A single IM generates 9 line flat optical frequency comb. The effects of modulation index, DC bias voltage and initial phase on the optical frequency comb flatness of these two schemes are analyzed and discussed. Since the bandwidth of the optical frequency comb is limited by the bandwidth of the modulator, two schemes of spreading the spectrum of the optical frequency comb are studied and proposed. Scheme one uses the principle of generating odd or even order optical sideband to realize the spread of spectral line spacing, and finally produces 15 and 20 lines of optical frequency comb. In the second scheme, the amplitude of the RF signal and the DC operating point of the DPMZM are set, and the 50 line broadband optical frequency comb is generated by using the idea of optical carrier cancellation. The relationship between the modulation index and the optical frequency comb performance of the proposed scheme is analyzed and discussed. The above scheme is verified by VPI simulation software and practical experiments. Finally, a point-to-point WDM communication system is constructed based on a single DPMZM generation 5-wire optical frequency comb as a light source. The single-wave 10Gb/s digital information is transmitted through 30km standard single-mode optical fiber by VPI simulation. The BER of the system is small.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.11

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