Quasi Symmetric Moderate Refractive Index Photonic Crystal Waveguides on Mesoporous Substrates

本文主要研究光波在含有有限二维光子晶体晶格结构的聚合物波导薄膜中传播的基本问题。最近，我们发现单指数限制波的传播和停止间隙，这种有限的二维光子晶体平板波导制成的纳米结构的非晶聚合物具有适度的折射率对比。研究这种新型光子晶体概念的动机源于这些材料在1.3μm波长下（以及某些聚合物在1.5μm波长下）的低固有光学损耗以及可以实现的大模式分布。在未来的技术应用中，当这种波导耦合到单模石英光纤时，这些可以起到保持插入损耗小的作用。扩展我们最近的工作，拟议的项目打算，在第一部分，澄清的几何参数和对称性的影响，在聚合物光子晶体平板波导中的波传播。在这里，我们感兴趣的是研究未扰动晶格和线性缺陷。在第二部分中，我们想弄清楚在什么条件下光波在光子晶体聚合物平板中的双限制引导是可能的。最后，我们计划研究光波在由新型电光聚合物制成的光子晶体板中的传播。例如，我们打算阐明这种结构中窄带缺陷态的电光调谐潜力。对于我们的系统的理论计算，我们使用三维时域有限差分和平面波方法来研究不同频率，偏振和传播方向的波的透射和反射。我们将利用电子束微影技术与反应性离子蚀刻技术来实现有希望的低损耗结构，并以光谱来表征。

We propose the research on fundamental aspects of optical wave propagation in thin polymer waveguiding films containing finite two dimensional (2d) photonic crystal lattice structures. We recently found singly index confined wave propagation and stop gaps in such finite 2d photonic crystal slab waveguides made from nanostructured amorphous polymers with a moderate refractive index contrast. The motivation to investigate this novel photonic crystal concept stems from the low intrinsical optical losses in these materials at 1.3µm wavelength (and also at 1.5µm in certain polymers) and from the large mode profiles that can be achieved. These may play a role to keep insertion losses small when such waveguides are coupled to monomode silica fibers in future technical applications. Extending our recent work, the proposed project intends, in the first part, to clarify the influence of geometrical parameters and symmetry on the wave propagation in polymer photonic crystal slab waveguides. Here, we are interested in investigating unperturbed lattices and linear defects. In the second part, we want to clarify under which conditions doubly confined guiding of light waves in photonic crystal polymer slabs is possible. Finally, we plan to investigate optical wave propagation in photonic crystal slabs made from novel electrooptical polymers. For instance, we intend to elucidate the electrooptical tuning potential of narrow band defect states in such structures. For theoretical calculations of our systems we use 3d-finite difference time domain and plane wave methods to investigate the transmission and reflection of waves of different frequencies, polarizations and directions of propagation. We will realize promising low loss structures by electron beam lithography and reacitive ion etching techniques and then characterize them spectroscopically.