In order to investigate the modulation phenomenon of pulse in the time domain and determine its frequency spectrum

an Optical Parametric Amplification-Frequency-Resolved Optical Gating（OPA-FROG）measurement scheme for optical arbitrary waveforms based on optical parametric amplification of crystal is presented in this paper.The program structure is simple and easy to implement.In the MATLAB environment

we use the Principal Component Generalized Projects（PCGP）algorithm to recovery the waveform.The results show that the scheme can achieve an accurate measurement of the amplitude and phase of arbitrary optical waveform.The characteristics of gating process of the gate pulse with gain amplification can realize the measurement of weak signals.