Active chiral control of GHz acoustic whispering-gallery modes

作者：Mezil Sylvain; Fujita Kentaro; Otsuka Paul H; Tomoda Motonobu; Clark Matt; Wright Oliver B; Matsuda Osamu^*

来源：Applied Physics Letters, 2017, 111(14): 144103.

DOI：10.1063/1.4994886

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. Published by AIP Publishing.

• 出版日期2017-10-2