Manipulating multidimensional electronic spectra of excitons by polarization pulse shaping.

A simulation study demonstrates how coherent control, combined with adaptive polarization pulse shaping and a genetic algorithm, may be used to simplify femtosecond coherent nonlinear optical signals of excitons. Cross peaks are amplified and resolved, and diagonal peaks are suppressed in the heterodyne-detected two-pulse echo signal from the Soret band of a porphyrin dimer coupled to a Brownian oscillator bath. Various optimization strategies involving the spectral, temporal, and polarization profiles of the second pulse are compared.