Application of Lasers in Electrochemistry

As laser radiation plays an important role in some of the experimental methods employed later, some fundamental aspects of lasers are discussed briefly here. The fact that lasers are more and more replacing conventional light sources in all types of optical applications can be understood by considering their fundamental advantages. Perhaps the most striking feature of laser radiation is its directionality due to a very 

Laser radiation can be focused down to dimensions of the wavelength of light. 

A large amount of energy can be concentrated into small spots, yielding high power densities. 

However, it is not only the spot size s that governs the final spatial resolution of the electrode reaction, but illumination of the sample is just the first step in a whole series of induced processes resulting in the final state of the system. For instance, in semiconductor interfaces the lateral hole drift causes an extension of the reaction zone. For the thermally activated processes, the heat conductivity of the sample determines the reaction zone. Therefore, both optical and physical effects determine the final spatial resolution of optical/electrical laser methods. 

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