Spectral Phase Interferometry for Direct Electric ield Reconstruction Comes as a system consisting of the mechanics, optics and user-friendly software. The device is used to measure spectral phase, spectral intensity, temporal intensity. It also has an autocorrelation function. The SPIDER device provides precise phase-amplitude measurement of ultrashort laser pulses. The device is widely used for on-line tuning of ampliier systems. The principle of operation is based on spectral shearing interferometry. The spectral phase property is reconstructed from a spectral interferogram registered by a CCD.