Determination of the profile of a single ultrashort optical pulse

A method of determining the temporal profile of a picosecond optical pulse was substantiated theoretically and checked experimentally. The amplitude and phase spectra were reconstructed from the spatial energy distribution in the second-harmonic beam generated noncollinearly by temporal "spectrons" of the initial pulse. Spectrons were formed by linear dispersive media exhibiting positive and negative dispersion. The method was checked experimentally at the 1.064 μm wavelength of a YAG:Nd laser. The spectral width (0.06 nm)and the pulse duration agreed with the calculated data.