Method and assembly for optical analysis of an ultrashort laser pulse

A single-shot optical autocorrelator device for analyzing an ultrashort laser pulse, the single-shot optical autocorrelator device comprising:

• a polarity separator for angularly separating an incident laser radiation beam with a fundamental optical frequency (ω) into two laser radiation beams with the fundamental frequency (ω) and linear polarities that are orthogonal to one another, said two beams forming an angle between them at the output of said separator, said angle being non-zero so that said beams at least partially overlap at the output of said separator;
• a type-II non-linear crystal, said non-linear crystal being arranged to receive said at least partially overlapping beams originating from said separator so as to generate, at the output of said crystal, a single laser radiation beam with a harmonic frequency (2ω), which is a second-order autocorrelation trace having an double optical frequency 2ω;
• at least one spectral filtering device configured to selectively allow the passage of said laser radiation beam with the harmonic frequency (2ω), while blocking said laser radiation beams with the fundamental frequency (ω), said at least one filtering device being placed between said non-linear crystal and a spatially resolved detection system in at least one direction;
• said non-linear crystal, said at least one spectral filtering device, and said detection system being arranged to detect a second-order intensimetric type single-shot autocorrelation trace at the double optical frequency 2ω.