Quadratic Array Spatial Solitons: New Phenomena in Nonlinear and Soliton Science

0098647 Stegeman空间孤子是一种无衍射光束，可以在克尔、可饱和克尔、光折变和二次非线性介质中自陷（参数混合的近相位匹配）。二次孤子基于二阶非线性X（2），并且在最简单的情况下由基波场和谐波场组成，当y传播时，基波场和谐波场相互自陷。以前的实验已经处理了孤子在均匀介质中引导，无论是在散装或波导。最近，位于耶拿的弗雷德里克·席勒大学的Falk Lederer小组预测，在几瓦的功率水平下，二次孤子也可以由准相位匹配（QPM）LiNbO3中的紧密间隔的平行通道波导阵列引导。这些阵列孤子是通过基场和谐波场之间以及阵列中相邻通道之间的强耦合来引导的。他们的第一次观察，表征和他们之间的相互作用是这里提出的方案的主旨。该研究有望首次观测到新的孤子、位置相关孤子相互作用以及阵列结构中的新的导向现象。这也应该导致新的知识，可以推广到该领域的非线性离散系统，一个领域不容易访问的实验data.PI是一个不可分割的和正式的一部分，欧洲共同体（EC）计划，研究新的应用QPM铌酸锂。欧洲的合作者包括福尔克·莱德勒，以及沃尔夫冈·索勒，他的小组（联合国。Paderborn）已经制造了相位匹配超过8 cm的QPM LiNbO3波导。在这样的样品中，对于20 μ m宽的阵列空间孤子，通常需要1 cm用于孤子控制操作或碰撞。因此，第一次这些波导提供了前景激发这样的孤子和调查多个顺序孤子相互作用。此外，这些样品允许孤子激发在瓦特峰值功率水平，减少了数量级比以前cases.In合作与耶拿和Paderborn组，PI提出了产生这样的阵列空间孤子在QPM铌酸锂平板波导，调查他们的属性，包括碰撞和电光和全光转向控制。PI的欧洲合作伙伴已经得到了ROSA的资助，这是一个欧盟计划，不幸的是，该计划不允许资助美国部分。PI在此申请资助该项目的组成部分。虽然该项目将侧重于基础科学，但也将评估应用潜力。由阵列引入的额外自由度导致了大量的新的稳定孤子模式，许多在均匀二次介质中没有类似物，并且一些在任何当前已知的非线性系统中不存在。它们的性质处于早期理论阶段，将在1550 nm波长下进行实验研究。初步计算揭示了丰富的相互作用谱，包括位置依赖的结果，并将进行实验研究。孤子现象与增益（已证明在铒注入QPM铌酸锂在帕德博恩）也将进行研究，包括聚焦，偏转等。此外，扫描的孤子通过改变其功率，通道分离，或折射率的电光阵列将进行研究。

0098647StegemanSpatial solitons are non-diffracting beams which can be self-trapped in Kerr, saturable Kerr, photorefractive and quadratically nonlinear media (near phase-matching for parametric mixing). Quadratic solitons are based on the second order nonlinearity X (2) and in the simplest case consist of a fundamental and a harmonic field which are mutually self-trapped as the y propagate. Previous experiments have dealt with solitons guided in homogeneous media, either in bulk or in waveguides. Recently Falk Lederer's group at Frederich Schiller University in Jena predicted that quadratic solitons can also be guided by arrays of closely spaced, parallel channel waveguides in Quasi-Phase-Matched (QPM) LiNbO3 at power levels of a few watts. These array solitons are guided by virtue of strongcoupling both between fundamental and harmonic fields, and between adjacent channels in the array. Their first observation, characterization and interactions between them are the thrust of the program proposed here. This research is expected to lead to the first bservations of novel solitons, position dependent soliton interactions and new guiding phenomena in array structures. This should also lead to new knowledge that can be generalized to the field of nonlinear discrete systems, an area not readily accessible by experiment to date.The PI is an integral and formal part of a European Community (EC) program to study novel applications of QPM LiNbO3. The European collaborators include Falk Lederer, as well as Wolfgang Sohler whose group (Un. Paderborn) has fabricated QPM LiNbO3 waveguides, phase-matched over 8 cms. In such samples for 20 um wide array spatial solitons, typically 1 cm is required for a soliton control operation or collision. Thus for the first time these waveguides offer the prospect of exciting such solitons and investigating multiple sequential soliton interactions. Furthermore, these samples allow soliton excitation at watt peak power levels, a reduction of orders of magnitude over previous cases.In collaboration with the Jena and Paderborn groups, the PI proposes to generate such array spatial solitons in QPM LiNbO3 slab waveguides, investigate their properties, including collisions and electro-optic and all-optical steering control. The PI's European partners are already funded by ROSA, an EC program which unfortunately does not allow funding of the US part. Here the PI requests funding for the component of the program.Although this program will be focused on basic science, the potential for applications will also be assessed. The extra degrees of freedom introduced by the array lead to a large variety of new stable soliton modes, many without analogs in homogenous quadratic media, and some which do not exist in any currently known nonlinear system. Their properties are in their early theoretical stages and will be investigated experimentally at 1550 nm wavelengths. Preliminary calculations have revealed a rich spectrum of interactions, including position-dependent outcomes, and they will be investigated experimentally. Soliton phenomena associated with gain (already demonstrated in erbium implanted QPM LiNbO3 at Paderborn) will also be investigated including focusing, deflection etc. Furthermore, scanning of the soliton across the array by changing its power, the channel separation, or the refractive index electro-optically will be studied.