Polarization-multiplexed vibrational sum frequency generation for comprehensive simultaneous characterization of interfaces.

We describe a novel three-pulse experimental arrangement for the simultaneous generation and subsequent resolution of all four electric-dipole allowed vibrational sum frequency generation polarization combinations. For noncentrosymmetric and achiral systems, this represents full characterization of all symmetry-allowed elements of the second-order susceptibility, providing a comprehensive intensity level assessment of the system under study. By measuring all relevant signals simultaneously, this approach enables assessment of molecular orientation and structure in dynamic, temporally evolving systems that were previously inaccessible by means of sequentially scanned acquisition of the individual tensor elements.