Investigation of temporal evolution of picosecond laser pulse by synchronized femtosecond laser pulse

In this paper, we theoretically and experimentally investigate the initial temporal characterization and the temporal evolution of a picosecond laser pulse by a synchronized femtosecond laser pulse. After theoretically analyzing the measurement principle, we experimentally measure the initial temporal characterization of the picosecond laser pulse. Further, the temporal evolution of the picosecond laser pulse propagating in different lengths of a carbon disulfide (CS2) is measured. We find that the initial temporal shape of the picosecond laser pulse is smooth and clean. As increasing of the CS2 length, the pulse width of the picosecond laser pulse has a trend of slight narrow owing to the spatiotemporal coupling effect.