【作者】 周海峰；

【导师】 江晓清；

【作者基本信息】 浙江大学 ， 微电子与固体电子学， 2009， 博士

【摘要】 不断呈现的各种业务需求、飞速发展的光通信技术以及逐步拓宽的应用领域大大促进了集成光子器件的研究与发展。为构建大容量、高速率的光通信网络,时下的光开关和光路由等交换系统正面临着巨大挑战。不仅如此,集成光学器件还快速拓展于能源、环境、医疗、生物、传感等领域。集成光电子器件的设计正朝着简易化(simpler)、智能化(Smarter)、小型化(smaller)、高速化(swifter)、节约化(saving energy and cost)的“5S”方向迈进。近年来,SOI基有源和无源器件的研究齐头并进,成为光电子领域最热门的方向之一。在揭开电子瓶颈之前,硅光子器件仍面临很多基本问题。比如,如何有效回避或利用光子波导中的偏振问题;如何实现超紧凑、低串扰、宽带宽的光开关器件;能否用硅基光子波导构建具有类似于电子器件的逻辑功能单元;怎样解决好硅与各种材料的混合集成问题等等。基于上述思想,本论文的目的在于:以光波导自映像原理为基础,探索功能新颖、工艺简单、控制方便、性能优良的光电子器件,并以SOI基CMOS兼容工艺为基础进行原理性试验。本文具创新性意义的工作主要集中于以下四个方面:1、对光波导的自映像原理进行了引伸和拓展。从光偏振的角度对自映像原理进行了推广,设计了一种新型的模式转换器;利用模式传输方法对平板波导和二维空间波导中的多模干涉进行了阐述和分析;论述了有限波导阵列中的自映像效应,分析了次近邻波导间的耦合对该效应的影响;讨论了无限波导阵列的传输特性与输入场之间的联系;提出了利用分离变量法和微扰法联合分析空间波导系统的解析模型,据此设计了粗波分复用器件。2、以自映像理论为基础,提出了多种结构紧凑、功能新颖、控制简便的集成光学器件。以3×3 MMI耦合器为基本结构,提出的多种器件,包括控制简单的、超紧凑1×3光开关;2~3bit的光学逻辑编码器;易于重组的波导型六端光环路器;利用光开关的各输出状态下所需相位调制量间的倍数关系,系统论证了可以简化外控电极及驱动方案的1×N的多值MMI开关;理论性的研究了基于多模干涉波导的空间逻辑编码器的驱动方案。3、兼用CMOS生产线和本实验室的硅基工艺条件,系统设计、原理性论证了所提器件的基本结构。以p-i-n载流子注入结构进行波导相位调制,采用0.8μm CMOS工艺线制作的调制器消光比达20dB;1×2光开关和2×2光开关的串扰分别可以达到18dB和17dB;器件速度达到几十ns量级。通过对实验传输曲线的拟合分析,讨论了硅载流子色散效应的伴随损耗对MZI型光开关串扰的影响。在本实验室条件下,攻克了等离子体干法刻蚀工艺,对刻蚀条件进行了优化;并摸索了一系列硅基热光器件的基础工艺。4、基于对Ce:YIG/Si/SOI非互易波导的数值分析,构思了多种硅基非互易器件。用微扰法比较分析了Ce:YIG/Si/SOI波导在增强非互易效应方面的优势;推导了磁光波导的三维全矢量BPM模拟的计算公式,并基于有限差分方法进行编程计算。将非互易相移引入到微谐振结构,达到了非互易器件小型化和功能化的目的。并且,利用耦合谐振环的MZI结构高带宽利用率等优点,提出了高隔离度的波导型双向多波长交错隔离器。本文的研究工作在数值计算、器件设计及工艺制作等多方面展开,所涉及研究课题和项目较多,在后续工作中将继续对所构思的各种器件进行充分的试验验证。作者在研究中以5S为设计思想,提出了多种具新功能、新特性的集成光子器件,期待在未来的光子集成回路中获得广泛应用。更多还原

【Abstract】 Continuously-emerged service requirement of human being,well-developed optical communication techniques and gradually-discovered application fields greatly boost the research and development of integrated photonic devices.Optical switching or routing systems are confronted with big challenges by the large-capacity and high-bit rate optical communication networks.Moreover,integrated optical devices gained wide-spread application in industry,military,energy,medicine,sensor,etc.To tailor the needs in different application fields,the device design strides forward to a common goal "Simpler, Smarter,Smaller,Swifter,and Saving energy & cost".Recently,researches on both the active and passive devices with silicon-on-insulator (SOI) material were underway and became a hot point in opto-electronics.Before successfully solving the bottleneck of micro-electronics,passive silicon devices still faced plenty of challenges:how to effectively evade or utilize the polarization in waveguide;how to realize a compact,low-crosstalk and broad-band optical switches;whether the photonic devices can implement the similar logic function to the electronic counterparts;how to tackle with the hybrid integration of silicon and the other useful materials,and so on.By employing the self-imaging(SIM) theory in optical waveguide,this thesis is intended to explore new schemes in the above spirit for optical devices with novel function, relaxed fabrication,easy controlling way and high performance.The basic physical effects in simple silicon devices are demonstrated by our own fabrication and CMOS foundry.The innovation of this thesis can be organized as four points:1.The SIM theory in many respects was deepened and extended.The SIM theory was generalized to the polarized mode issue,which results in a novel polarization rotator. The SIM phenomena in finite waveguide arrays were discussed by taking the secondary-neighborhood coupling into account.Light propagation in infinite waveguide arrays were investigated under different input conditions.The analytical model is established by combining the separate variable method and perturbation method to simplify spatial waveguide system.The design procedure of coarse wavelength division multiplexer (CWDM) based on the four-waveguide system is also illustrated.2.Several devices based on SIM theory are proposed,with merit in function,size and the controlling style.Taking the 3×3 MMI coupler as the basic element,this thesis proposed the easy-controlled ultra-compact 1×3 optical switch,2~3bit optical logic coder,a re-arrangeable six-port optical circulator.By using the multiplier relations of the modulation magnitudes for different switching state,1×N multi-valued controlled MMI switch was proposed to simplify the electrodes and controlling schemes.The method was therotically applied to steer light into spatial logic patterns with multimode waveguide.3.The basic units of the above-mentioned devices are systematically designed and demonstrated in silicon by using the CMOS industry and our own fabrication condition. By using 0.8μm CMOS line and the p-i-n carrier injection structure,the extinction ratios of the fabricated modulators can reach about 20dB.The crosstalks of the 1×2 and 2×2 MMI-based switches are 18dB and 17dB respectively.The device speed is about at the scale of tens of ns.Through fitting the experimental transmission curves,the performance limits to the Mach-Zehnder interferometric(MZI) switch crosstalk are systematically evaluated.In our lab,the inductively coupled plasma(ICP) reactive ion etcher was put into use after the parameter optimization.The fabrication techniques of the thermo-optical devices are also explored.4.Nonreciprocal silicon devices are conceived by numerically analyzing the magneto-optical Ce:YIG/Si/SiO2 waveguide.The perturbation method was used to observe the advantages of the Ce:YIG/Si/SiO2 structure in producing nonreciprocal phase shift (NPS).The 3-D semi-vector BPM formula are deduced and utilized to take the magneto-optical(MO) effect into account.NPS is introduced into micro-ring resonator to miniaturize the nonreciprocal device and improve the device performance.Besides, bi-directional multi-wavelength interleaved isolator is also proposed to favor the wavelength division multiplexing(WDM) system,by employing the Ring-coupled MZI structure.This thesis is related to multiple research directions,including the numerical calculation,device proposal and fabrication techniques.Partial work of these proposals and their demonstration are still underway.The author tries to carry out the above-stated "5S" spirit in the whole thesis and put forward several integrated optical devices with novel function and performance,which can be expected to facilitate the OEIC in the near future.更多还原