Research on femto-second laser pulse width and pulse waveform measurement technology

Femto-second laser has an important application prospect in the fields of laser fusion, satellite precision ranging, laser micromachining, etc. And it is the main pump source of terahertz(THz) wave. The principles of the measurement methods of femto-second laser pulse width and pulse waveform are introduced. The advantages and disadvantages of the measurement methods of autocorrrelation (AC), frequency-resolved optical gating (FROG), and spectral phase interferometry for direct electric-field reconstruction (SPIDER) are presented. The AC is characterized by wide range of pulse width measurement and compact structure, however it does not have the ability of pulse waveform measurement. The SPIDER requires high quality of input laser beam and it is not suitable for fast measurement of laser pulse width in a large range. In order to meet the test requirements of ultra-short laser pulse width and pulse waveform in the range of 10 fs to 5 ps, a femto-second laser pulse width and pulse waveform measurement device was developed by using AC and FROG methods, and the time resolution is better than 2 fs.