论文标题
超快二分法的全光重构
All-optical Reconfiguration of Ultrafast Dichroism in Gold Metasurfaces
论文作者
论文摘要
光学元面已经成为纳米级轻型操作的有前途的平台，包括通过使用飞秒激光脉冲激发的超快全光控制。最近，已经利用了二分性元面积以前所未有的速度调节光的极化状态。在这里，我们从理论上通过泵探针光谱法预测和实验证明了通过简单地作用于泵脉冲的极化来重新配置金跨表面的超快二分法信号的能力，该信号被证明可以重塑光学接触的时空分布。光诱导的各向异性响应是由平衡外载体驱动的，并在子picsecond的时间窗口中熄灭，可以通过将激发的极化方向调节到完整的符号反转，从而很容易控制强度。这项工作证明，非线性元信息具有灵活性，可以在完全全面的可重新配置平台中量身定制其超快光学响应。
Optical metasurfaces have come into the spotlight as a promising platform for light manipulation at the nanoscale, including ultrafast all-optical control via excitation with femtosecond laser pulses. Recently, dichroic metasurfaces have been exploited to modulate the polarization state of light with unprecedented speed. Here, we theoretically predict and experimentally demonstrate by pump-probe spectroscopy the capability to reconfigure the ultrafast dichroic signal of a gold metasurface by simply acting on the polarization of the pump pulse, which is shown to reshape the spatio-temporal distribution of the optical perturbation. The photoinduced anisotropic response, driven by out-of-equilibrium carriers and extinguished in a sub-picosecond temporal window, is readily controlled in intensity by tuning the polarization direction of the excitation up to a full sign reversal. This work proves that nonlinear metasurfaces offer the flexibility to tailor their ultrafast optical response in a fully all-optically reconfigurable platform.
