Mapping the transient concentration field within the diffusion layer by use of the digital holographic reconstruction

The digital holographic reconstruction was employed in studies of dynamical changes of the concentration and diffusion layer at the Cu/CuSO4 solution interface during the galvanostatic electrodeposition of copper in 0.24 mol dm−3 CuSO4 solution. During electrochemical reaction processes, changes of solution’s refractive index, which were caused by changes of the concentration, were recorded in situ and were shown in holograms. Changes in the phase of the object beam were caused by changes in the refractive index when they passed through the solution. The distribution of the phase difference (the phase change) was obtained by numerical reconstruction of holograms to reflect concentration changes. The process of numerical reconstruction of holograms is described in detail, and the two-dimensional concentration distribution is presented in illustration of the diffusion layer and concentration changes.