ABSTRACT
Spectral Interferometry (SI)[22], Spectral Phase Interferometry for Direct Electric-field Reconstruction (SPIDER)[23-27], and Pump-Probe technology[6,28,29]. In the above methods, photodiodes and high-speed streak camera are only suitable for measuring the pulse width of hundreds femtosecond due to the effect of measurement resolution, which are not suitable for measuring the pulse width less than 100 fs. FROG and SPIDER have proven capable of measuring the temporal and phase characteristics of a given pulses accurately, but it is need to assume uniform transverse spatial distribution. FROG is needed complex iterative algorithm to retrieve the pulse shape of premeasured pulse in time domain, which only gives approximate information. SPIDER is particularly suited for measuring the spectral phase of a pulse, which has an advantageous for tracking the influence of dispersion on an ultrashort pulse. SPIDER neither moves components nor requires iterative algorithm, but it does not give the pulse width information directly. It needs the multiplied result of its measurement spectrum and phase, and then reconstructs the pulse shape and width by Fourier Transform. Compared with other methods, FROG and SPIDER are more complex in experimental operation. The intensity autocorrelation method is simple operation and no need complex calculation, but it is only suitable for measuring the pulse width information and need to assume the shape of premeasured pulse during the measurement process. While the coherent intensity autocorrelation method can provide some phase information, the accurate phase information is not given directly.
