Giorgini A, Avino S, Malara P, De Natale P, Yannai M, Carmon T, Gagliardi G
Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (INO), via Campi Flegrei, 34-Comprensorio A. Olivetti, 80078 Pozzuoli (Naples), Italy.
Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (INO), Largo E. Fermi 6, 50125 Firenze, Italy.
Phys Rev Lett. 2018 Feb 16;120(7):073902. doi: 10.1103/PhysRevLett.120.073902.
Liquid droplets are ubiquitous in nature wherein surface tension shapes them into perfect spheres with atomic-scale smooth surfaces. Here, we use stable droplets that cohost equatorial acoustical and optical resonances phase matched to enable the exchange of energy and momentum between sound and light. Relying on free-space laser excitation of multiple whispering-gallery modes, we harness a triple-resonant forward Brillouin scattering to stimulate optomechanical surface waves. Nonlinear amplification of droplet vibrations in the 60-70 MHz range is realized with spectral narrowing beyond the limit of material loss, thereby activating the droplet as hypersound-laser emitter.
液滴在自然界中无处不在，表面张力将它们塑造成具有原子尺度光滑表面的完美球体。在此，我们使用共承载赤道声学和光学共振且相位匹配的稳定液滴，以实现声光之间的能量和动量交换。依靠对多个回音壁模式的自由空间激光激发，我们利用三共振向前布里渊散射来激发光机械表面波。在60 - 70兆赫兹范围内实现了液滴振动的非线性放大，其光谱变窄超出了材料损耗的极限，从而将液滴激活为超声音激光发射器。
