Experimental demonstration of sharp Fano resonance in optical metamaterials composed of asymmetric double bars
Experimental demonstration of sharp Fano resonance in optical metamaterials composed of asymmetric double bars
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DOI：
10.1364/ol.39.004057
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发表时间：
2014-07-01
期刊：
影响因子：
3.6
通讯作者：
Hane, Kazuhiro
中科院分区：
文献类型：
--
作者：
Moritake, Yuto;Kanamori, Yoshiaki;Hane, Kazuhiro
实验证明了非对称双棒（ADBs）构成的超材料在光学区存在Fano共振。采用剥离法制备了ADB超材料，并测量了其光谱。在1100 nm波长附近，测量的光谱清楚地显示出由于ADB结构的弱不对称性而引起的尖锐的Fano共振。Fano共振的最高品质因子（Q因子）为7.34。计算光谱显示出与实验光谱相同的趋势。此外，在Fano谐振条件下，通过电磁场计算揭示了沿沿着每个杆流动的感应电流的异相。这些反相电流降低了Fano模的辐射损耗，导致ADB超材料中Fano共振的高Q因子。随着非对称度变小，Q因子减小，并且由于焦耳损耗的影响变得显著，Fano共振消失。(C)2014年美国光学学会
We experimentally demonstrated Fano resonance in metamaterials composed of asymmetric double bars (ADBs) in the optical region. ADB metamaterials were fabricated by a lift-off method, and the optical spectra were measured. Around a wavelength of 1100 nm, measured optical spectra clearly showed sharp Fano resonance due to weak asymmetry of the ADB structures. The highest-quality factor (Q-factor) of the Fano resonance was 7.34. Calculated spectra showed the same tendency as the experimental spectra. Moreover, in a Fano resonant condition, out of phase of induced current flowing along each bar was revealed by electromagnetic field calculations. These antiphase currents decreased radiative loss of the Fano mode, resulting in a high Q-factor of the Fano resonance in ADB metamaterials. As the degree of asymmetry became small, the Q-factor decreased, and the Fano resonance disappeared because the effect of Joule loss became significant. (C) 2014 Optical Society of America