Spectral phase characterization of ultrashort pulse using fringe free interferometry

There are presented analytical and experimental results of a novel method which enables significant simplifications in spectral shearing interferometry as applied for ultrashort optical pulse measurements. The method attempts to improve the superiority in conventional Spectral Phase Interferometry for Direct Electric-field Reconstruction (SPIDER). It doesn't split a test pulse into two parts, but compensates for the delay time between two quasi-monochromatic frequency components in a chirped pulse with spectral and temporal shear to produce an interferogram without fringe. Fringe free interferograms could simplify data processing procedures and reduce the restriction on resolution of spectrometers. The experimental setup avoids the influence of material dispersion with real-time and single-shot nature, and could be made up as a miniaturization measurement device. Although being short of the beauties in SPIDER, it still could be an optional femtosecond pulse measurement method in certain conditions. (C) 2014 Optical Society of America.