Guided Wave Optics in Super-EO Materials

9522740泰勒这项研究的总体目标是获得支持和促进高电光系数钨青铜铁电材料(“超电光材料”)在各种导波光学器件中应用的分析和实验结果。德克萨斯A&A&M开发的在钨青铜衬底上制造首批低损耗波导和电光调制器的技术将作为拟议项目的基础。该波导是通过一种简单的工艺来制造的，其中来自图案化表面膜的静态应变产生局部折射率增加。罗克韦尔国际科学中心多年来一直向德克萨斯农工机械公司提供超EO材料，在拟议的项目过程中，该中心将继续发挥这种合作作用。研究将在五个关键领域进行：(1)静态应变光(SSO)波导建模，(2)器件设计，(3)材料表征，(4)调制器和开关开发，以及(5)可调谐滤波器研究。考虑到应变光和电光对局域折射率变化的贡献，我们将计算SSO光波导中TE和TM极化的二维折射率分布。波导模分析将采用变分方法。将测量波导和器件模型所需的参数，如应变光学系数和电光系数、折射率和热膨胀系数。最近发现的“自极化”效应将被实验研究，以确定在高温下处理SSO器件后，在没有极化的情况下存在大的电光效应的条件。我们将在洛克韦尔衬底上设计、制作和表征利用SSO波导的电光截止调制器、耦合波导型开关和可调沟道分插滤波器。该研究将为超电光材料在导波器件中的应用奠定基础，并有望在未来十年内在宽带通信网络中得到越来越多的应用。人们将寻求在性能上比传统的导波电光器件的衬底材料LiNbO_3提高数量级的调制器和开关。我们将探索具有前所未有的调谐范围、低串扰和最小电功率消耗的新型波分复用器。成功的演示应该会加强罗克韦尔对钨青铜衬底商业化的兴趣，以便它们将普遍用于研究和设备应用。***

9522740 Taylor The overall objective of this research is to obtain analytical and experimental results which support and promote the application of high-electrooptic-coefficient tungsten bronze ferroelectric materials ("super-EO materials") in a variety of guided wave optical devices. Techniques developed at Texas A&M for making the first low-loss waveguides and electrooptic modulators in tungsten bronze substrates will serve as the foundation for the proposed project. The waveguides are produced by a simple process in which static strain from a patterned surface film creates a localized refractive index increase. The Rockwell International Science Center, which has supplied super-EO materials to Texas A&M for several years, will continue in this collaborative role during the course of the proposed project. Research will be conducted in five critical task areas: (1) static strain optic (SSO) waveguide modeling, (2) device design, (3) material characterization, (4) modulator and switch development, and (5) tunable filter investigations. Two-dimensional refractive index profiles for TE and TM polarizations in SSO waveguides will be computed, considering both strain-optic and electrooptic contributions to the localized index change. A variation method will be utilized for waveguide mode analysis. Parameters needed for the waveguide and device models, such as strain-optic and electrooptic coefficients, refractive indices, and thermal expansion coefficients, will be measured. The recently discovered "self-poling" effect will be investigated experimentally to determine the conditions under which a large electrooptic effect is present without poling after processing of an SSO device at elevated temperatures. Electrooptic cutoff modulators, coupled waveguide switches, and tunable channel dropping filters which make use of the SSO waveguides will be designed, fabricated in the Rockwell substrates, and characterized. The proposed research will lay the groundwork for using super-EO materials in guided wave devices which could find increasing application in broadband communication networks over the next decade. Modulators and switches which exhibit order-of-magnitude improvement in performance over their counterparts in LiNbO3 - the traditional substrate of choice for guided wave electrooptic devices - will be sought. New channel-dropping filters for wavelength multiplexing with unprecedented tuning range, low crosstalk, and minimal electrical power dissipation will be explored. Successful demonstrations should reinforce Rockwell's expressed interest in commercializing the tungsten bronze substrates so that they will be generally available for research and device application. ***