Measurement of picosecond laser pulses using an autocorrelator and a FROG apparatus

Abstract

In this paper, we report experimental results of measuring picosecond laser pulses using a second-harmonic generation (SHG) intensity autocorrelator. This home-made apparatus of the intensity autocorrelation is an attempt to measure the SHG pulse's intensity change with time. It is clear that an intensity autocorrelation can be used for measuring the pulse length of the ultrashort pulses laser. Using this SHG intensity autocorrelator, we measured the pulse length of a diodepumped picosecond passively mode-locked Yb:SSO laser which emits at a central wavelength of 1061nm at a repetition rate of 52MHz, and a mode-locked picosecond laser amplified system centered on 1064nm at a pulse repetition frequency of 1K HZ. Compared with the commercial autocorrelator, this setup has a larger measurement range, higher accuracy, and more reliable results. In addition, using a high resolution spectrum instrument the apparatus becomes a FROG. The full information of the pulse can be retrieved by using a frequency-resolved optical grating (FROG) algorithm. This setup should be very useful for further optimization of the diode pumped picosecond laser.