Optical tweezing by photochemistry (Conference Presentation)

Abstract

Optical tweezing;by photochemistry is a novel concept in the field of optical manipulation. I discuss it in azo-polymer films through theory and experiments. I will show that optical tweezing can be obseved by a photochemical force, e.g. photoisomerization force which leads to a spring type motion. This force is derived from a harmonic light potential that moves the azo-polymer, and it is parenting to optical tweezers since it occurs in the presence of a gradient of light intensity, but it is quite different in the sense that it requires photoisomerization to occur. The azo-polymer’s motion is governed by four competing forces: the photoisomerization force, and the restoring optical gradient and elastic forces, as well as the random forces due to spontaneous diffusion.