Department of Physical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata , Mohanpur 741246, India.
ACS Nano. 2017 Feb 28;11(2):1641-1648. doi: 10.1021/acsnano.6b07406. Epub 2017 Feb 15.
Fano resonance is observed in a wide range of micro- and nano-optical systems and has been a subject of intensive investigations due to its numerous potential applications. Methods that can control or modulate Fano resonance by tuning some experimentally accessible parameters are highly desirable for realistic applications. Here we present a simple yet elegant approach using the Mueller matrix formalism for controlling the Fano interference effect and engineering the resulting asymmetric spectral line shape in an anisotropic optical system. The approach is founded on a generalized model of anisotropic Fano resonance, which relates the spectral asymmetry to physically meaningful and experimentally accessible parameters of interference, namely, the Fano phase shift and the relative amplitudes of the interfering modes. The differences in these parameters between orthogonal linear polarizations in an anisotropic system are exploited to desirably tune the Fano spectral asymmetry using pre- and postselection of optimized polarization states. The concept is demonstrated on waveguided plasmonic crystals using Mueller matrix-based polarization analysis. The approach enabled tailoring of several exotic regimes of Fano resonance in a single device, including the complete reversal of the spectral asymmetry, and shows potential for applications involving control and manipulation of electromagnetic waves at the nanoscale.
法诺共振在广泛的微纳光学系统中被观察到，由于其众多潜在的应用，已经成为了一个研究热点。由于其众多潜在的应用，因此，人们非常希望能够找到一些通过调整一些实验上可访问的参数来控制或调制法诺共振的方法。在这里，我们提出了一种简单而优雅的方法，使用 Mueller 矩阵形式来控制法诺干涉效应，并在各向异性光学系统中设计产生的非对称光谱线形状。该方法基于各向异性法诺共振的广义模型，将光谱不对称性与干涉的物理意义和实验上可访问的参数联系起来，即法诺相移和干涉模式的相对幅度。在各向异性系统中正交线性偏振之间的这些参数的差异被用来利用优化的偏振态的预选择和后选择来期望地调整法诺光谱的不对称性。该概念在基于 Mueller 矩阵的偏振分析的波导等离子体晶体上得到了演示。该方法可以在单个器件中实现法诺共振的几种奇异状态的定制，包括光谱不对称性的完全反转，并展示了在纳米尺度上控制和操纵电磁波的应用潜力。
