arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2102.13074physics.opticsphysics.app-ph
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零折射率波导中的松弛相位匹配约束

Relaxed phase-matching constraints in zero-index waveguides

Justin R. Gagnon, Orad Reshef, Daniel H. G. Espinosa, M. Zahirul Alam, Daryl I. Vulis, Erik N. Knall, Jeremy Upham, Yang Li, Ksenia Dolgaleva, Eric Mazur, Robert W. Boyd

摘要:

材料的非线性光学响应是频率转换、全光信号处理、分子光谱学和非线性显微镜等应用的基础。然而,所有这些参数非线性光学过程的效用受到相位匹配要求的阻碍。准相位匹配、双折射相位匹配和高阶模式相位匹配都已被开发来解决该约束,但是迄今为止所展示的方法遭受仅针对单个特定布置的光束(通常是共同传播的)进行相位匹配的不便,从而导致笨重的实验配置和用于集成器件的大覆盖区。在这里,我们实验证明,这些相位匹配的要求可以满足在一个参数的非线性光学过程中的多个,如果不是所有的,配置的输入和输出光束时,使用低折射率介质。我们的测量构成了第一个实验观察的方向无关的相位匹配介质足够长的相位匹配问题是相关的。我们演示了四波混频从光谱上不同的共同和反向传播的泵浦和探测光束,向后产生的非线性信号,并激发出平面的探测光束。这些结果清楚地表明,低折射率介质的独特性质放松了传统的相位匹配约束,这可以用来促进非线性相互作用和非线性器件,从而增加了低折射率材料的既定特殊性能。

英文摘要:

The nonlinear optical response of materials is the foundation upon which applications such as frequency conversion, all-optical signal processing, molecular spectroscopy, and nonlinear microscopy are built. However, the utility of all such parametric nonlinear optical processes is hampered by phase-matching requirements. Quasi-phase-matching, birefringent phase matching, and higher-order-mode phase matching have all been developed to address this constraint, but the methods demonstrated to date suffer from the inconvenience of only being phase-matched for a single, specific arrangement of beams, typically co-propagating, resulting in cumbersome experimental configurations and large footprints for integrated devices. Here, we experimentally demonstrate that these phase-matching requirements may be satisfied in a parametric nonlinear optical process for multiple, if not all, configurations of input and output beams when using low-index media. Our measurement constitutes the first experimental observation of direction-independent phase matching for a medium sufficiently long for phase matching concerns to be relevant. We demonstrate four-wave mixing from spectrally distinct co- and counter-propagating pump and probe beams, the backward-generation of a nonlinear signal, and excitation by an out-of-plane probe beam. These results explicitly show that the unique properties of low-index media relax traditional phase-matching constraints, which can be exploited to facilitate nonlinear interactions and miniaturize nonlinear devices, thus adding to the established exceptional properties of low-index materials.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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