【作者】 张乐天；

【导师】 张玉书；

【作者基本信息】 吉林大学 ， 微电子学与固体电子学， 2004， 博士

【摘要】 随着全球通信业务量的飞速增长，光通信系统和网络对带宽和容量的需求也不断提高。波分复用技术可以实现大容量和多功能，在网络业务应用方面具有巨大的潜力，成为光纤通信的首选技术。列阵波导光栅因其传输损耗小、波长分辨率高、易与光纤耦合等优点，被认为是密集波分复用系统最有发展前途的一种新型器件，而基于AWG的各种光子器件代表了实现DWDM系统的关键实用技术之一。阵列波导光栅是由一系列输入输出波导、阵列波导和两个聚焦块波导组成的，阵列波导中相邻波导间的长度差为常数值，可以起到光栅的作用，从而完成不同波长光的复用和解复用功能。本论文介绍了AWG的基本结构和功能，从理论上推导了AWG的光波导方程，总结了AWG的研究进展及其应用，阐述了目前AWG的相位误差补偿、温度误差补偿和波长平坦化以及双折射控制等性能优化措施。条形光波导是集成光路和各种集成光学器件的基本元件，研制硅基阵列波导光栅，就要从研究硅基二氧化硅光波导开始。本论文依据光波导理论，并结合实验工作，分别设计了火焰水解法与反应离子刻蚀和火焰水解法与紫外写入技术制作条形光波导的单模传输条件及波导尺寸，对于10GeO2-90SiO2的RIE型光波导，包层折射率为1.4513，芯层为1.4639，设计单模波导尺寸为4×6μm2；而对于10GeO2-90SiO2的紫外诱导型光波导，上下包层折射率为1.4513，左右为1.4639，芯层为1.4727，设计其单模波导尺寸为6×9μm2。这一工作为硅基AWG的制作打下了好的基础。硅基二氧化硅平面波导技术是90年代发展起来的，由于硅加工工艺非常成熟，便于光电子器件的大规模集成，因此硅基二氧化硅光波导受到人们的关注。硅基二氧化硅厚膜材料的制备一直是硅基AWG器件制作的重点和难点之一。在国内，我们率先采用火焰水解法制备出了20μm厚，损耗小于0.1dB/cm的玻璃态二氧化硅厚膜以及锗掺杂5~40mol%的二氧化硅波导材料。重点研究了二氧化硅及锗掺杂材料的高温退火过程，讨论了材料折射率、厚度与退火温度的关<WP=142>系。制备的锗掺杂10mol%的二氧化硅在1150℃下退火后表面均匀平滑，粗糙度很小，厚度约为5μm，折射率为1.4639，消光指数在10-6量级，损耗小于0.527dB/cm，这样的材料完全适合用作波导芯层。实验中，采用SEM和AFM分别分析了材料的表面宏观和微观特征；采用XPS分析了材料的组分；采用XRD分析了材料的结构特征；采用VASE测量了SiO2及Ge掺杂的SiO2膜的折射率和消光指数。结果表面，我们利用FHD制备出了光滑透明、平整度好的玻璃态SiO2和Ge掺杂的SiO2厚膜。这一工作对国内硅基二氧化硅平面波导器件，如AWG器件的研究是具有重要意义的。锗硅玻璃的紫外光致折变效应具有一个潜在的优势就是应用在集成光路和集成光子元件中。我们利用工作波长为248nm的KrF准分子激光研究了锗硅材料的紫外光敏性。采用火焰水解法制备的Ge掺杂量为14mol%的SiO2薄膜，在经过高压注氢处理后，于KrF准分子激光下曝光，在1550nm处的光致折变量的相对值达到了0.341%，这一数值接近了目前相关实验的国际水平。通过不同Ge掺杂量，不同曝光时间的系列实验，得出了曝光时间对光致折变的影响；同时得到了Ge含量不同引起的折射率正负变化及厚度的致密和膨胀现象，对于高锗掺杂35%的薄膜经紫外曝光后，得到了-0.234%的相对折射率变化值和3.96%的厚度膨胀变化量。经过理论分析，验证了紫外光致折变机理的“色心模型”和“应力松弛模型”。讨论了材料的掺氢技术，根据掺氢后材料的紫外可见吸收谱和PL谱，分析了我们制备的材料掺氢后产生了GeO缺陷，这对于进一步提高材料的光敏性是很有帮助的。硅基阵列波导光栅典型的制作工艺是火焰水解法或等离子增强化学气相沉积法与反应离子刻蚀工艺相结合。这种制作工艺在国外已经比较成熟，但是，它也存在工艺复杂、刻蚀设备昂贵、重复性不好和器件中心波长不准、波导双折射等问题。而紫外光致折变效应已广泛地应用在平面光波导器件制作和改善传统RIE法制作的AWG器件性能上。在此基础上，我们提出了采用紫外写入技术在SiO2平面波导上直接写入AWG器件的制作工艺，设计了工艺流程、提出了基本参数，讨论了一些可能的优化措施。首次自行设计制作了用于KrF紫外曝光的镀金属Cr的石英振幅掩模板，利用该掩模板在SiO2波导上成功地写入了平面波导光栅(1460mJ/cm2/pulse，6Hz，10min)，且摸索了掩模板的阈值能量密度为1530mJ/cm2/pulse。紫外写入技术制作AWG，比传统的反应离子刻蚀技术制作的AWG具有更多的优点，即制作周期短、成本低、重复性好； 器件也将具有插入损耗低、无偏振依赖性、低串话、中心波长精确等性能优势。本论文的创新点体现在以下几个方面：(1)首次提出将锗硅玻璃材料对紫外光的光致折变效应应用于制作光通信系统<WP=143>中的AWG光波导器件，即紫外写入技术制作AWG。由于传统的AWG刻蚀方法难度较大，我们利用激光光子能量大的特点，将紫外光直接写入引入AWG制作技术中以代替传统的刻蚀技术，作光子加工，可以达到很高的精度，具有一定的创新性。(2)在国内首次采用FHD在单晶Si上制备了SiO2和Ge掺杂SiO2膜，经高温致密化处理后，获得了光滑透明的玻璃态厚膜，膜更多还原

【Abstract】 AbstractWith the rapid increase of global message volume, optical communication system’s demand for bandwidth and capacity improves constantly. Wavelength division multiplex technology is capable of realizing large capacity and multifunction. It has great potential in network service application and becomes preferred technologh in optical fiber communication. Arrayed waveguide grating is considered as a kind of new promising device due to its low propagation loss, high wavelength resolution, easily coupled with optical fiber. The components based on AWG represent one of the key enabling technologies for DWDM systems.The arrayed waveguide grating consists of input/output waveguides, two focusing slab regions and a phase-array of multiple channel waveguides with the constant path length difference ΔL between neighboring waveguides. It can work as grating and complete the function of multiplexing and demultiplexing for light with different wavelength. In this paper, we introduced the basic structure and function of AWG, deduced the optical waveguide equations of AWG in theory, summarized the studied progress and application of AWG, and formulized optimized means in performances of the phase error compensation and temperature error compensation and flat spectral response and birefringence control of AWG. Single-mode channel waveguide is the basic element of planar lightwave circuits and integrated lightwave devices. It’s the first step of fabricating arrayed waveguides grating to prepare silica-on-silicon waveguides. Based on the optical waveguide theory and combining with our experiments, we designed single-mode transmission condition and waveguide dimension fabricated by flame hydrolysis deposition and reactive ion etching (RIE) or UV-writing technology. For 10GeO2-90SiO2 RIE-etched waveguide, the refractive index of cladding and core are 1.4513 and 1.4639, respectively, and the designed single-mode dimension is 4×6μm2. For 10GeO2-90SiO2 UV-written waveguide, the refractive index of upanddown, left right and core are 1.4513, 1.4639 and 1.4727, respectively, and the designed single-mode dimension is 6×9μm2. This result provides a good foundation for fabrication of Si-based AWG.Silica-on-silicon planar waveguide technology has developed since 1990’s, and <WP=145>more attention has been paid to silica waveguide on silicon because of mature silicon processing technique and easy photoelectronic device’s integration on a large scale. The preparation of silica-on-silicon waveguide materials is always one of the hard and key steps to fabricate AWG devices. We are the first in China to fabricate 20μm-thickness and 0.1dB/cm-loss SiO2 glass films and 5~40mol% Ge-doped silica waveguide material. We studied emphatically the consolidation of SiO2 and Ge-doped SiO2, and discussed the relations of the refractive index, thickness and the annealing temperature. 10mol% Ge-doped SiO2 is smooth and uniform after annealing at 1150℃ for 2h. It is suitable for core of waveguide with 5μm-thickness and small roughness, 10-6 in the extinction coefficient. Its refractive index at 1550nm is 1.4639, and its loss is less than 0.527dB/cm. In the experiment, we have analyzed the samples by SEM, AFM, XPS, XRD and VASE. It can be concluded that we have fabricated smooth SiO2 and Ge-doped SiO2 glass film. This work is important in China for the research on silica-on-silicon planar waveguide device, such as AWG.The effect of photoinduce refractive index changes in germanosilicate glass by UV writing has a potential advantage in integrated optical circuit and photonics devices. We have studied the photosensitivity of germanosilicate through KrF excimer laser operating at 248nm. The relative refractive index change of 14mol% Ge-doped SiO2 film is 0.341% after exposure followed by hydrogen loading, which approaches to the reported results in this research field. We have obtained the dependence of irradiation time on the refractive index changes through a series of experiments. The positive and negative refractive index change with the更多还原