Active chiral control of GHz acoustic whispering-gallery modes
Active chiral control of GHz acoustic whispering-gallery modes
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DOI：
10.1063/1.4994886
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发表时间：
2017-10
影响因子：
4
通讯作者：
S. Mezil;K. Fujita;P. Otsuka;M. Tomoda;M. Clark;O. Wright;O. Matsuda
中科院分区：
文献类型：
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作者：
S. Mezil;K. Fujita;P. Otsuka;M. Tomoda;M. Clark;O. Wright;O. Matsuda
我们选择性地产生手性表面声学回音壁模式在千兆赫兹范围内的微观磁盘通过超快时域技术结合空间光调制器。主动手性控制是通过利用一个半圆弧的形式，定位在样品上的光泵的空间分布，打破顺时针和逆时针传播模式的对称性。时空傅立叶变换的干涉监测的二维声场测量到微米分辨率允许单独的手征模式和它们的方位角模式顺序，正和负，要区分。特别是，模式与15倍旋转对称性，我们证明了超快手征控制的表面声波在微声学系统的皮秒时间分辨率。应用包括无损检测和表面声波器件。
We selectively generate chiral surface-acoustic whispering-gallery modes in the gigahertz range on a microscopic disk by means of an ultrafast time-domain technique incorporating a spatial light modulator. Active chiral control is achieved by making use of an optical pump spatial profile in the form of a semicircular arc, positioned on the sample to break the symmetry of clockwise- and counterclockwise-propagating modes. Spatiotemporal Fourier transforms of the interferometrically monitored two-dimensional acoustic fields measured to micron resolution allow individual chiral modes and their azimuthal mode order, both positive and negative, to be distinguished. In particular, for modes with 15-fold rotational symmetry, we demonstrate ultrafast chiral control of surface acoustic waves in a micro-acoustic system with picosecond temporal resolution. Applications include nondestructive testing and surface acoustic wave devices.