1. General
While characterization of spectral intensity and spatial profile of an ultrafast laser source is rather straightforward in most cases, measurement of spectral phase requires a bit more complicated approach. One of the techniques widely used for this purpose is spectral phase interferometry for direct electric-field reconstruction (SPIDER).
The principle of operation is based on spectral shearing interferometry. In a few words, the spectral phase property is reconstructed from a CCD-registered spectral interferogram, while the other CCD monitors spectral amplitude of the input pulse.
The phase-amplitude characteristic in time domain is obtained by Fourier transformation phase-amplitude characteristic in frequency domain by using a linear and non-iterative reconstruction algorithm. The SPIDER pulse diagnostic system offers measurement of spectral phase, spectral and temporal intensity and displays the autocorrelation function of the pulse. Acquisition and analysis PC software come as a standard package.
