Bordeu, I.Volpe, GiovanniStaforelli, J. P.2016-02-082016-02-0820130277-786Xhttp://hdl.handle.net/11693/27938Date of Conference: 22-26 July 2013Conference Name: 8th Iberoamerican Optics Meeting and 11th Latin American Meeting on Optics, Lasers, and Applications, 2013The study of diffusion in a crowded and complex environment, such as inside a cell or within a porous medium, is of fundamental importance for science and technology. Combining blinking holographic optical tweezers and sub-pixel video microscopy permits one to study Brownian motion in confined geometries. In this work, in particular, we have studied the Brownian motion of two colloidal particles interacting hydrodynamically with each other. The proximity between the two microspheres induces a space-dependence in the particles diffusion coefficient and, therefore, a spurious drift. We measure this drift and evaluate the magnitude of the spurious force associated with it. We present the optoelectronic tools employed in the experiment and we discuss the experimental results.EnglishBlinking optical tweezersBrownian motionDiffusion gradientsDigital video microscopyHolographic optical tweezersStochastic differential equationsConference Paper10.1117/12.2027533