Stimulated Brillouin scattering in nanoscale silicon step-index waveguides: a general framework of selection rules and calculating SBS gain
Stimulated Brillouin scattering in nanoscale silicon step-index waveguides: a general framework of selection rules and calculating SBS gain
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DOI：
10.1364/oe.21.031402
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发表时间：
2013-12-16
期刊：
影响因子：
3.8
通讯作者：
Wang, Zheng
中科院分区：
文献类型：
--
作者：
Qiu, Wenjun;Rakich, Peter T.;Wang, Zheng
提出了一种利用本征模与本征模的重叠积分计算光波导中受激布里渊散射（SBS）增益系数的方法。SBS耦合的全矢量公式严格地解释了微纳米尺度波导中辐射压力和电致伸缩的影响。我们发现，这两个贡献在SBS耦合中起着至关重要的作用，模式限制接近亚波长尺度。通过分析每个贡献的光学力，我们表明，光学力的空间对称性决定了可激发的弹性模式的选择规则。通过将这种方法应用于矩形硅波导，我们演示了如何光学力分布和弹性模式的配置文件共同确定的幅度和缩放的SBS增益在前向和后向SBS过程。我们进一步将这种方法应用于模内和模间SBS过程的研究，并证明了不同的光学模式之间的耦合是必要的激发所有可能的对称性的弹性模式。例如，我们表明，强大的偏振间耦合可以实现之间的基本TE和TM类模式的悬浮硅波导。(C)2013年美国光学学会
We develop a general framework of evaluating the Stimulated Brillouin Scattering (SBS) gain coefficient in optical waveguides via the overlap integral between optical and elastic eigen-modes. This full-vectorial formulation of SBS coupling rigorously accounts for the effects of both radiation pressure and electrostriction within micro- and nano-scale waveguides. We show that both contributions play a critical role in SBS coupling as modal confinement approaches the sub-wavelength scale. Through analysis of each contribution to the optical force, we show that spatial symmetry of the optical force dictates the selection rules of the excitable elastic modes. By applying this method to a rectangular silicon waveguide, we demonstrate how the optical force distribution and elastic modal profiles jointly determine the magnitude and scaling of SBS gains in both forward and backward SBS processes. We further apply this method to the study of intra-and inter-modal SBS processes, and demonstrate that the coupling between distinct optical modes are necessary to excite elastic modes with all possible symmetries. For example, we show that strong inter-polarization coupling can be achieved between the fundamental TE- and TM-like modes of a suspended silicon waveguide. (C) 2013 Optical Society of America