基于微环谐振腔光码分多址编解码器的设计及特性分析

发布时间：2018-03-02 16:43

本文选题：OCDMA　切入点：光电子集成　出处：《天津大学》2014年博士论文　论文类型：学位论文

【摘要】：光码分多址(OCDMA)技术结合了电CDMA的优点和光纤通信的带宽优势,是实现全光通信的重要技术之一。光编解码器作为OCDMA系统的核心器件,正在向更高集成度、更易调谐、更多用户的方向发展。微环谐振腔凭借其模式体积小,选频特性优越,支持多调谐方式以及兼容微电子批量加工等优点,成为满足光编解码器发展需求的有效方案之一。目前,该类型编解码器在理论和结构设计方面,主要存在三方面的问题:一是部分编解码方案欠佳,体现在利用微环一维编解码方式,限制了系统容量的扩展;二是编解码器性能不高,解码输出自/互相关峰值比较低;三是用户容量不易扩展,编解码信道频带利用率低。此外,在OCDMA系统传输过程中常伴随旋转信号的传输,这就需要实现对旋转光信号的接收、发送及解码。针对上述问题,本文在以下方面展开了研究工作:1.利用微环谐振腔阵列下载端反射谱结合相移器相位变换,提出了以微环阵列为核心单元的二维相干光编解码器结构;建立了微环阵列结构的传输矩阵方程;分别研究了耦合双环、串联三环编解码器结构的反射谱特性;分析了上述两种编解码器的结构参数与自/互相关峰值比的关系。通过数值仿真得到这两种结构波长/相位二维解码的时域/频域输出谱线和自/互相关峰值比,理论上验证了微环谐振腔阵列编解码器的可行性。2.设计并研究了编解码器优化方法,提出了最佳耦合系数法、耦合系数高斯\平坦化分布优化法以及半径优化法。针对并联耦合双环、串联三环两种编解码器结构,对比其优化前后的编解码器性能。理论计算表明,优化后的编解码器结构提高了自/互相关峰值比。3.利用游标效应易于扩展微环自由频谱宽度的优点,优化了编解码器结构,增大了系统用户容量。分析了游标效应下,微环串联编解码器结构的3dB带宽、矩形因子、峰值反射率以及伪模抑制特性,仿真实现了该结构的二维波长跳频/相位编解码。结果表明,具有游标效应的微环串联结构可以扩展用户容量。4.针对OCDMA传输过程中的旋转光信号接收和发送,设计并实现了一种聚合物倒锥透镜型单通道旋转连接器。理论分析了该器件的结构参数,阐述了它的制备方法,并实验测试了该旋转连接器的性能。
[Abstract]:Optical code division multiple access (OCDMA) technology, which combines the advantages of CDMA and bandwidth of optical fiber communication, is one of the most important technologies to realize all-optical communication. As the core device of OCDMA system, optical codec is becoming more integrated and tunable. The microring resonator has become one of the effective schemes to meet the development needs of optical codec because of its advantages of small mode size, excellent frequency selection, multi-tuning support and compatible microelectronic batch processing. There are three main problems in the theory and structure design of this type of codec: firstly, the scheme of partial coding and decoding is poor, which is reflected in the use of microloop one-dimensional coding and decoding mode, which limits the expansion of system capacity; Second, the performance of codec is not high, the peak value of decoding output is low, the user capacity is not easy to expand, and the frequency band efficiency of codec channel is low. In addition, the transmission of rotating signal is often accompanied by the transmission of rotating signal in OCDMA system. This requires receiving, transmitting and decoding rotating optical signals. In view of the above problems, this paper has carried out research work in the following aspects: 1.Using the reflection spectrum of the download end of the microring resonator array combined with phase shifter phase transformation, A two-dimensional coherent optical codec structure with microloop array as the core unit is proposed, the transfer matrix equation of the microloop array structure is established, and the reflectance spectrum characteristics of the coupled double-ring and three-ring codecs are studied respectively. The relationship between the structural parameters of the two kinds of codec and the peak ratio of self-correlation / cross-correlation is analyzed. The time / frequency domain output lines and the autocorrelation peak ratio of the two kinds of structured wavelength / phase two-dimensional decoding are obtained by numerical simulation. The feasibility of the microring resonator array codec is theoretically verified. 2. The optimization method of the codec is designed and studied, and the optimal coupling coefficient method is proposed. The coupling coefficient Gao Si\ flattened distribution optimization method and radius optimization method are used to compare the performance of parallel coupled double loop and series three loop codecs before and after optimization. The optimized codec structure improves the ratio of self-correlation to cross-correlation peak value .3.Using the advantages of the cursor effect to extend the free spectrum width of the microloop, the structure of the codec is optimized and the user capacity of the system is increased. The 3dB bandwidth, rectangular factor, peak reflectivity and pseudo-mode suppression of the microloop series codec structure are simulated and realized. The simulation results show that, The microloop series structure with Vernier effect can expand the user capacity. 4. For receiving and transmitting rotating optical signals during OCDMA transmission, A kind of polymer inverted cone lens single channel rotary connector is designed and implemented. The structure parameters of the device are theoretically analyzed and its fabrication method is described. The performance of the rotary connector is tested experimentally.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.1

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