Optical interference fields: an excellent tool kit to study Brownian dynamics

摘要

Optical interference of two waves with different wave vectors generates a harmonic spatial profile of the optical intensity. This well known property combined with mechanical effect of light provides an excellent possibility to study the behavior of stochastic system in periodic potentials. Sub-micron size objects dispersed in liquid suffer from noticeable Brownian motion. This free motion can be significantly influenced (directed, suppress, modified) if the objects are illuminated by an optical interference pattern of sufficient intensity. Therefore, the Brownian dynamics in static periodic potentials of variable depth of the potential profile or extra tilt of the potential landscape can be studied. Moreover, applying the principle of optical conveyor combined with a precise method of object tracking with respect to the interference pattern paves the way for similar studies but in motional potential landscapes. We present a group of new experiments studying particle behavior in such fields.