Coherent phonon oscillations in ZnS excited by noncollinear optical parametric amplifier

This study has observed coherent LO phonon oscillations in ZnS for the first time using a noncollinear optical parametric amplifier (NOPA) as a light source. Merits using NOPA are not only tunability in a visible region but also shorter pulse width than those of conventional optical parametric amplifiers. Therefore, NOPA is suitable for observing coherent phonon oscillations near the exciton resonance to investigate the interaction between phonons and excitons.