【作者】 陆思；

【导师】 严瑛白；

【作者基本信息】 清华大学 ， 光学工程， 2004， 博士

【摘要】 阵列波导光栅型波分复用器对于实现未来密集波分复用全光网具有重要的意义。本论文在新型和特殊结构阵列波导光栅的设计,低损耗设计方法,光波导与光纤间新型高效耦合器的研究,以及器件的加工与测试等方面进行了相应的研究工作。基于阵列波导光栅的像差理论,利用三个无像差点约束三个主要结构参量,设计了新型平场聚焦阵列波导光栅,使得所有工作波长的输出信号都聚焦在与光束传输方向垂直的直线上,并进一步将其拓展为同时具有平输入场和平聚焦场的新型平场波长路由器。以多模干涉耦合器替代标准罗兰圆星形耦合器,构成一种特殊结构的阵列波导光栅,利用它仅在低通道数时具有较好性能的特点,提出了基于双通道多模干涉耦合器型阵列波导光栅的新型光梳状分波器方案,其设计简单,结构紧凑,易于实现微小频率间隔,并易于与其它光无源器件集成。全面分析了阵列波导光栅的插入损耗。针对损耗来源,讨论了各项损耗的计算方法及结构参量对损耗的影响。基于降低损耗的设计思路,逐步确定各结构参量和几何轮廓参量,在聚合物材料上设计了低损耗平场聚焦阵列波导光栅。提出一种具有集成化结构的衍射光学模式转换器,可以消除光波导与单模光纤之间的模式失配,从而实现高效耦合。其中的衍射光学器件通过数值迭代位相恢复算法进行优化设计,在迭代算法中引入一种新的混和远场振幅约束,可以达到很高的模式转换质量。本设计适用于任意结构的光波导与单模光纤的耦合,也适用于具有任何椭圆模场纵横比的LD半导体激光器与单模光纤的耦合。首次采用电子束直写技术在一种具有良好特性的新型聚合物材料上研制新型平场聚焦阵列波导光栅,通过测试实验,初步验证了加工工艺的可行性,并分析了加工误差对器件性能的影响。此外,还测试了一个二氧化硅标准罗兰圆阵列波导光栅样片,并对二者进行了对比。更多还原

【Abstract】 Arrayed waveguide grating (AWG) is of great importance to the future dense wavelength division multiplexing (DWDM) all optical network (AON). In this dissertation, new-type and special-type AWG schemes are studied, the low insertion loss design method is discussed and a novel high-efficiency fiber-to-waveguide coupler is presented. The researches on the fabrication of a polymeric AWG are also reported.Based on the aberration theory of AWG, a new-type flat-field AWG is designed. The focal signals of all wavelengths of operation are focusing along a straight line perpendicular to the propagation direction. Three stigmatic points restrain three dominant geometry parameters. Furthermore, a new-type flat-field wavelength router with both flat input field and flat focal field is also designed.A novel integrated DWDM interleaver scheme is presented based on double-channel AWG with multimode interference (MMI) couplers instead of standard Rowland-circle star couplers. MMI-AWG interleaver can realize narrow channel spacing through simple design procedure. It’s simple in structure, compact in size, and convenient for integration with integrated planar waveguide multi/demultiplexers.The insertion loss of AWG is analyzed and the low-loss design method is discussed. A low-loss polymeric flat-field AWG is designed by optimizing the structure and geometry parameters.An integrated diffractive optical mode converter scheme is presented to eliminate the mode mismatch between optical waveguide and single mode fiber (SMF). Then, a high coupling efficiency can be achieved. The diffractive optical element (DOE) is designed using iterative phase retrieval algorithm. In the iterative algorithm, a new modification of far-field amplitude constraint is introduced to provide very high mode-conversion quality. The scheme is applicable for low-loss coupling between SMF and any type of waveguide <WP=6>structure. And it’s also applicable for efficiently coupling SMF with semiconductor laser diode (LD) of any aspect ratio of the elliptical field.For the first time, a new-type flat-field AWG is fabricated using electron-beam direct writing based on polymeric optical waveguide. The waveguide core-layer material is a newly-developed negative tone epoxy Novolak resin (ENR) polymer. The polymeric flat-field AWG sample is tested by an optoelectronics passive device test set. The feasibility of the fabrication technique is prelimimarily proved. The performance deteriorations due to fabrication errors are analyzed. And besides, a silica-based standard Rowland-circle AWG sample is also tested and compared with the polymeric one.更多还原