Anticrossing Behavior in Nanolayered Heterostructures Caused by Coupling between a Planar Waveguide Mode in an Anthracene Single Crystal and a Silver Surface Plasmon Polariton Mode: Implications for Attenuated Total Reflection Spectroscopy
Anticrossing Behavior in Nanolayered Heterostructures Caused by Coupling between a Planar Waveguide Mode in an Anthracene Single Crystal and a Silver Surface Plasmon Polariton Mode: Implications for Attenuated Total Reflection Spectroscopy
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蒽单晶中的平面波导模式与银表面等离子体激元模式之间的耦合引起的纳米层异质结构的反交叉行为：对衰减全反射光谱的影响
DOI：
10.1021/acsanm.0c02571
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发表时间：
2021
影响因子：
5.9
通讯作者：
Bando Kazuki
中科院分区：
文献类型：
--
作者：
Inou Ikumi;Fujimoto Masato;Bando Kazuki
本文研究了有机单晶中平面波导（PWG）模式与表面等离子激元（SPP）模式之间的耦合。在强耦合状态下，在耦合模的色散曲线上观察到抗交叉行为。虽然以前的研究已经利用了自旋涂层有机波导，但到目前为止，还没有关于使用单晶波导的报道。在与PWG-SPP耦合系统相关的许多研究中，已经在光谱中观察到所谓的法诺线形状，有望在表面等离子体共振传感器中找到用途。与此同时，从法诺线形状到拉比分裂的转变随着耦合的增加而被观察到，这在基础物理学中引起了相当大的关注。由于有机单晶具有很强的光学各向异性，因此方向色散对耦合强度的影响预计是显著的。在目前的研究中，我们开发了角度分辨透射微光谱学，即使在非辐射区域，也可以对面内尺寸为数百微米的有机单晶进行光学测量。由于使用传统的衰减全反射测量方法测量如此小的样品是困难的，因此通过在指数匹配油中旋转样品来测量非辐射区域的透射光谱。据此，得到了反映PWG和SPP模式耦合的色散曲线。
Coupling between a planar waveguide (PWG) mode in an organic single crystal and a surface plasmon polariton (SPP) mode is investigated in this paper. Anticrossing behavior appearing under the strong coupling regime was observed in the dispersion curves of the coupled modes. Although previous studies have utilized spin-coated organic waveguides, to date, there have been no reports on the use of single-crystalline waveguides. The so-called Fano line shapes have been observed in spectra in numerous studies related to PWG–SPP coupled systems, which are expected to find utility in surface plasmon resonance sensors. Meanwhile, transitions from Fano line shapes to Rabi splitting have been observed with increase in coupling and have attracted considerable attention in fundamental physics. As organic single crystals exhibit strong optical anisotropy, the influence of directional dispersions on coupling strength is expected to be significant. In the present study, we have developed angle-resolved transmission microspectroscopy that enables optical measurements of an organic single crystal with an in-plane dimension of hundreds of micrometers even in the nonradiative region. Because measuring such a small sample using conventional attenuated total reflection measurements is difficult, the transmission spectra in the nonradiative region were measured by rotating the sample in index-matching oil. Accordingly, dispersion curves reflecting the coupling between the PWG and SPP modes were obtained.