The diffraction of a laser beam while crossing a quasi-twodimensional cell in which a fractal electrodeposition takes place is presented. The features of the diffraction on the fractal edge are dependent on the current intensity through the cell. We observe that the diffractive properties of the fractal change in time after the stopping of the growth process, and totally disappear after a lapse of time of the order 300 s. In the anode zone, the behavior is entirely different. It is characterized by the appearance of high gradients of the refractive index generated by the metal ions created in the anode region. The observed beam divergence is explained using a model based on a curved surface phase optical wedge. The results are tested by analysis of moire´ fringe patterns.
Constantin P. Cristescu,
Alexandru M. Preda,
Ion M. Popescu,
"Diffraction of a laser beam at the edge of a fractal electrodeposit," Optical Engineering 35(6), (1 June 1996). http://dx.doi.org/10.1117/1.600997