Weerawarne Darshana L, Gao Xiaohui, Gaeta Alexander L, Shim Bonggu
Department of Physics, Applied Physics and Astronomy, Binghamton University, State University of New York, Binghamton, New York 13902, USA.
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
Phys Rev Lett. 2015 Mar 6;114(9):093901. doi: 10.1103/PhysRevLett.114.093901. Epub 2015 Mar 2.
We report on harmonic generation experiments and calculations in air to investigate the theoretical prediction of Kolesik et al. [Opt. Lett. 35, 2550 (2010)] for testing the recently proposed higher-order Kerr effect model. Our observations show that although the fifth-order nonlinearity is non-negligible, the overall defocusing effect via the higher-order nonlinearities is sufficiently small that plasma formation should be a main defocusing mechanism in high power filamentation. We also explore cross-phase modulation via the optical Kerr effect, and find that the higher-order nonlinearities can significantly alter the phase matching of harmonic generation.
我们报告了在空气中进行的谐波产生实验和计算，以研究科莱西克等人[《光学快报》35, 2550 (2010)]的理论预测，用于测试最近提出的高阶克尔效应模型。我们的观察结果表明，尽管五阶非线性不可忽略，但通过高阶非线性产生的整体散焦效应足够小，以至于等离子体形成应该是高功率成丝过程中的主要散焦机制。我们还通过光学克尔效应探索了交叉相位调制，并发现高阶非线性可以显著改变谐波产生的相位匹配。
