Mesoscopic mechanical motion of single particles achieved by switching of photon force through photochromic reactions
Abstract
Radiation force, which is the mechanical interaction between light and objects, can be divided into three: scattering force, absorption force, and gradient force. Scattering force and absorption force are caused by light scattering and light absorption, respectively, and the both forces push an object toward light propagation direction. On the other hand, the gradient force acts in the direction of the spatial gradient of the light intensity. When the refractive index of a fine particle is larger than that of the surrounding medium, the gradient force pushes the particle in the direction along which the light intensity increases. In the optical manipulation so far, radiation forces due to non-resonant light has been generally used. However, optical manipulation based on resonant absorption force has been recently proposed and demonstrated in theoretical and experimental studies. In this presentation, I will introduce several studies that realized the micromechanical motion of small objects by switching the absorption force using photochromic reactions.