Anomalous Dispersion Enhanced Nonlinear Optical Devices

9521664 Singer The PI建议演示和研究反常色散优化切伦科夫相位匹配二次谐波的产生，并研究其对级联三阶非线性的影响。切伦科夫相位匹配理论表明，当本征相位匹配与切伦科夫相位匹配相结合时，可以大大提高二次谐波的产生效率，最近的研究表明，级联的非线性可以发生大的相移。模拟结果表明，即使在不完全本征相位匹配的情况下，效率也有很大的提高。切伦科夫相位匹配与适当的本征相位匹配方案相结合，消除了关键的制造或材料特性。反常色散已被证明是有机溶液中的一种有效的本征相位匹配技术，最近在聚合物光波导中也是如此。与切伦科夫过程一起使用的反常色散还通过引导包层中的二次谐波光来克服反常色散相位匹配中的吸收效应。我们将演示这种类型的相位匹配，并研究其对电场极化聚合物光波导的制备和材料参数的依赖关系。这种结构依赖于由聚合物掺杂新近开发的反常色散非线性光学染料组成的极化非线性光学层。我们将研究平板和沟道波导结构。对基光的非线性相移也进行了研究。反常色散可能代表了非线性光学相互作用的一种重要的增强机制，这种机制依赖于相位匹配特性。这将导致用于光学数据存储和处理的更高效的光子器件。***

9521664 Singer The PI proposes to demonstrate and study anomalous dispersion optimized Cerenkov phase-matched second harmonic generation and to investigate its effect on cascaded third-order nonlinearities. Theories of Cerenkov phase-matched second harmonic generation in waveguides indicate that intrinsic phase-matching when coupled with Cerenkov phase-matching leads to large enhancements in second harmonic generation efficiency, and more recently, have suggested that large phase-shifts in cascaded nonlinearities can occur. Simulations indicate large enhancements in efficiency even with incomplete intrinsic phase-matching. The use of Cerenkov phase- matching in combination with an appropriate intrinsic phase- matching scheme eliminates critical fabrication or material properties. Anomalous dispersion has been shown to be an effective intrinsic phase-matching technique in organic solutions, and recently in polymeric waveguides. The use of anomalous dispersion along with the Cerenkov process also overcomes the effect of absorption in anomalous dispersion phase-matching by guiding the second harmonic light in the cladding. We will demonstrate this type of phase matching and study its dependence on fabrication and material parameters in electric-field-poled polymeric waveguides. The structures rely on a poled nonlinear optical layer composed of a polymer doped with a recently developed anomalous dispersion nonlinear optical dye. Both slab and channel waveguide structures will be investigated. The nonlinear phase shift of the fundamental light will also be studied. Anomalous dispersion may represent an important enhancement mechanism for nonlinear optical interactions which depend on phase- matching properties. This would lead to more efficient photonic devices for application in optical data storage and processing. ***