arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2112.02004physics.optics
收藏

电介质超颖表面中的级联光学非线性

Cascaded optical nonlinearities in dielectric metasurfaces

Sylvain D. Gennaro, Chloe F. Doiron, Nicholas Karl, Prasad P. Iyer, Michael B. Sinclair, Igal Brener

摘要:

自从激光器被发现以来,光学参量非线性一直是高效光转换源的核心。通常,厚透明晶体或准相位匹配波导与相位匹配技术结合使用,以选择单个参数过程。近年来,由于人工结构材料的快速发展,在亚波长谐振腔中,光学混频已经在纳米尺度上实现。对于这些波长尺度结构,相位匹配变得宽松,并且原则上,所有允许的非线性过程都可以平等地发生。这可以通过级联(由几个频率混合步骤组成)过程促进谐波产生。然而,到目前为止,所有关于电介质超颖表面的报道都假设频率混合来自直接(单步)非线性过程。在这项工作中,我们证明了级联的二阶光学非线性的存在,通过分析从一个高度非线性超颖表面结合偏振选择规则和晶体对称性的第二和第三波混频。我们发现,从级联过程中的三波混频信号可以从传统的三次谐波产生的强度相当,表面非线性是主要的机制,有助于级联二阶非线性

英文摘要:

Since the discovery of the laser, optical parametric nonlinearities have been at the core of efficient light conversion sources. Typically, thick transparent crystals or quasi-phase matched waveguides, are utilized in conjunction with phase-matching techniques to select a single parametric process. In recent years, due to the rapid developments in artificially structured materials, optical frequency mixing has been achieved at the nanoscale in subwavelength resonators arrayed as metasurfaces. Phase matching becomes relaxed for these wavelength-scale structures, and all allowed nonlinear processes can, in principle, occur on an equal footing. This could promote harmonic generation via a cascaded (consisting of several frequency mixing steps) process. However, so far, all reported work on dielectric metasurfaces have assumed frequency mixing from a direct (single step) nonlinear process. In this work, we prove the existence of cascaded second-order optical nonlinearities by analyzing the second and third wave mixing from a highly nonlinear metasurface in conjunction with polarization selection rules and crystal symmetries. We find that the third wave mixing signal from a cascaded process can be of comparable strength to that from conventional third harmonic generation, and that surface nonlinearities are the dominant mechanism that contributes to cascaded second order nonlinearities

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。

↑