论文标题
观察等离子波导阵列中的Wannier-Stark梯子
Observation of the Wannier-Stark ladder in plasmonic waveguide arrays
论文作者
论文摘要
Evanescylyed耦合的波导是研究和可视化紧密结合系统中的波动力学的强大平台。在这里，我们研究了表面等离子体偏振子在介电载荷表面等离子体极化波导阵列中的传播，其传播恒定梯度充当有效的外部电位。使用泄漏辐射显微镜，我们在实际空间中观察单位激发波袋的周期性呼吸和在高斯激发多个波导的情况下进行振荡运动。相应的动量解析光谱由相同间隔模式组成。我们分别将这些观察结果解释为Bloch振荡和Wannier-Stark梯子的等离子类似物。
Evanescently coupled waveguides are a powerful platform to study and visualize the wave dynamics in tight-binding systems. Here, we investigate the propagation of surface plasmon polaritons in arrays of dielectric loaded surface plasmon polariton waveguides with a propagation constant gradient acting as an effective external potential. Using leakage radiation microscopy, we observe in real-space for single site excitation a periodic breathing of the wavepacket and an oscillatory motion in the case of Gaussian excitation of multiple waveguides. The corresponding momentum resolved spectra are composed of sets of equally spaced modes. We interpret these observation as the plasmonic analogues of Bloch oscillations and the Wannier-Stark ladder, respectively.
