Astrath N G C, Flizikowski G A S, Anghinoni B, Malacarne L C, Baesso M L, Požar T, Partanen M, Brevik I, Razansky D, Bialkowski S E
Department of Physics, Universidade Estadual de Maringá, Maringá, PR, Brazil.
Faculty of Mechanical Engineering, University of Ljubljana, Ljubljana, Slovenia.
Light Sci Appl. 2022 Apr 20;11(1):103. doi: 10.1038/s41377-022-00788-7.
Precise control over light-matter interactions is critical for many optical manipulation and material characterization methodologies, further playing a paramount role in a host of nanotechnology applications. Nonetheless, the fundamental aspects of interactions between electromagnetic fields and matter have yet to be established unequivocally in terms of an electromagnetic momentum density. Here, we use tightly focused pulsed laser beams to detect bulk and boundary optical forces in a dielectric fluid. From the optical convoluted signal, we decouple thermal and nonlinear optical effects from the radiation forces using a theoretical interpretation based on the Microscopic Ampère force density. It is shown, for the first time, that the time-dependent pressure distribution within the fluid chiefly originates from the electrostriction effects. Our results shed light on the contribution of optical forces to the surface displacements observed at the dielectric air-water interfaces, thus shedding light on the long-standing controversy surrounding the basic definition of electromagnetic momentum density in matter.
精确控制光与物质的相互作用对于许多光学操纵和材料表征方法至关重要，在众多纳米技术应用中也起着至关重要的作用。然而，就电磁动量密度而言，电磁场与物质相互作用的基本方面尚未得到明确确立。在这里，我们使用紧聚焦脉冲激光束来检测介电流体中的体光学力和边界光学力。从光学卷积信号中，我们基于微观安培力密度的理论解释，将热光学效应和非线性光学效应与辐射力解耦。首次表明，流体中随时间变化的压力分布主要源于电致伸缩效应。我们的结果揭示了光学力对在介电空气 - 水界面观察到的表面位移的贡献，从而揭示了围绕物质中电磁动量密度基本定义的长期争议。
