论文标题
基于磁弹性异质结构的窄带旋转Terahertz发射器
A Narrowband Spintronic Terahertz Emitter based on Magnetoelastic Heterostructures
论文作者
论文摘要
窄带Terahertz（THz）辐射对于高分辨率光谱识别至关重要，但是由飞秒（FS）激光驱动的窄带THZ源仍然很少。在这里，计算预测的是，金属/介电/磁弹性异质结构可以使FS激光脉冲转换为一个多周期的THZ脉冲，其狭窄的线宽向〜1.5 GHz转换为〜1.5 GHz，这与单周期宽带THZ脉冲从现有的FS-Laser-Laser-Laser-exced-exced-exced the中相反。结果表明，这种窄带THZ脉冲源自磁弹性膜中Thz自旋波的激发和长距离传输，当金属膜的厚度和磁弹性膜的厚度都落入特定范围时，可以通过从金属膜的FS激光照射获得的短应变脉冲来实现。因此，这些结果揭示了一种基于异质结构设计实现窄带THZ脉冲的光学生成的方法，这也对THZ宏伟的设备的设计有影响。
Narrowband terahertz (THz) radiation is crucial for high-resolution spectral identification, but a narrowband THz source driven by femtosecond (fs) laser has remained scarce. Here, it is computationally predicted that a metal/dielectric/magnetoelastic heterostructure enables converting a fs laser pulse into a multi-cycle THz pulse with a narrow linewidth down to ~1.5 GHz, which is in contrast with the single-cycle, broadband THz pulse from the existing fs-laser-excited emitters. It is shown that such narrowband THz pulse originates from the excitation and long-distance transport of THz spin waves in the magnetoelastic film, which can be enabled by a short strain pulse obtained from fs laser irradiation of the metal film when the thicknesses of the metal and magnetoelastic films both fall into a specific range. These results therefore reveal an approach to achieving optical generation of narrowband THz pulse based on heterostructure design, which also has implications in the design of THz magnonic devices.
