Analysis of electromodulated optical second-harmonic response at a metal/electrolyte interface using a local surface-site charge-displacement model

We present aspects of a general approach for the analysis of second-harmoni c response at a metal/electrolyte interface. Analysis is based on a combina tion of principles from classical system identification and pattern recogni tion with a previously derived explicit and general representation of modul ated second-harmonic response on the molecular level. This study emphasizes the adaptation of our approach :Ind associated representation for the form ulation of feature variables whose purpose is to extract features associate d with observed trends in modulated second-harmonic signals, Our developmen t introduces the concept of representing the multidimensional processes res ponsible for second-harmonic generation by means of a one-dimensional stati onary stochastic process. This approach allows us to extract trends in expe rimental data correlated with molecular level charge displacements and reso nant effects. The paper concludes with a series of analyses that illustrate the :applicability of our approach and suggest possible pathways for its e xtension.