Time-resolved phase-sensitive second harmonic generation spectroscopy

• DOI: 10.1063/1.4909522
• Publication Date: 2015-02-23T18:00:29Z
• Authors: Paweł J. Nowakowski; David A. Woods; Colin D. Bain; Jan R. R. Verlet
• Keywords: Malachite green

A methodology based on time-resolved, phase-sensitive second harmonic generation (SHG) for probing the excited state dynamics of species at interfaces is presented. It an interference measurement between SHG from sample and a local oscillator generated reference together with lock-in to remove large constant offset interference. The technique characterized by measuring phase dye malachite green water/air interface. key attributes are that observed signal directly proportional concentration, in contrast quadratic dependence non-phase sensitive SHG, real imaginary parts 2nd order non-linear susceptibility can be determined independently. We show method highly provide high quality short data acquisition times.