Materials World Network: Nanoscale Structure and Shaping of Ferroelectric Domains

提高对铁电畴的成核和生长的理解，特别是在铌酸锂和钽酸锂晶体和波导中，对畴结构和畴壁研究的创新方法，以及在这些材料中利用亚微米和纳米级畴结构的设备的开发，是这个跨大西洋研究项目的目标，有五个小组的贡献：Simon Phillpot（佛罗里达大学）建立了铁电畴壁的理论模型，Volkmar Dierolf（里海大学）使用稀土和拉曼光谱来监测畴壁的结构和动力学，并使用光辅助书写畴图案，Karsten Buse（波恩大学）使用泵浦和探针技术在快速和超快时间尺度上观察畴成核，并通过非线性过程书写亚波长畴。Venkatraman Gopalan（宾夕法尼亚州立大学）使用扫描探针工具来绘制和检测畴，并实现了基于纳米畴结构的光子带隙超棱镜，Wolfgang Sohler（帕德博姆大学）使用电场在铌酸锂衬底的表面和大部分（ridge）波导中写入（亚）微米畴图案。温度和光辅助极化技术，以及具有后向非线性耦合的集成光学参数振荡器的发展，在中红外光谱范围内提供了新的调谐和光谱特性。

Improved understanding of nucleation and growth of ferroelectric domains especially in lithium niobate and lithium tantalate crystals and waveguides, innovative methods for domain structuring and for domain wall investigation, as well as development of devices that utilize sub-micron- and nano-sized domain structures in these materials are the goals of this transatlantic research project with contributions from five groups: Simon Phillpot (University of Florida) with theoretical modelling of ferroelectric domain walls, Volkmar Dierolf (Lehigh University) with rareearth and Raman spectroscopy to monitor the structure and dynamics of domain walls and with light-aided writing of domain patterns, Karsten Buse (University of Bonn) with the observation of domain nucleation on the fast and ultrafast time scale applying pump-and-probe techniques, with writing of sub-wavelength domains by nonlinear processes, and with the realization of an electro-optically controlled Bragg reflector, Venkatraman Gopalan (Penn State University) with scanningprobe tools to pattern and to detect domains and with the realization of photonic band-gap superprisms based on nano-domain structures, and Wolfgang Sohler (University of Paderbom) with the writing of (sub-)micron domain patterns in the surface and in the bulk of (ridge) waveguides in lithium niobate substrates using electric field-, temperature- and light-assisted poling techniques, and with the development of integrated-optical parametrical oscillators with backward nonlinear coupling offering new tuning and spectral properties in the mid-infrared spectral range.