Temporal superresolution of ultrashort laser pulses
Résumé
We introduce the notion of temporal superresolution for ultrashort laser pulses, by analogy with the well-known method of optical superresolution in imaging systems. Simple linear spectral masks are presented, that shapes a laser pulse into a central peak of very short duration, well below the Fourier limited width of Gaussian pulses, but accompanied by low intensity satellite pulses. A proof-of-principle experiment is presented, using a short pulse, high intensity laser system. Such lasers may induce very strongly non linear phenomena in laser-matter interactions, suppressing the effect of the satellite pulses and therefore fully mimicking shorter light pulses. As an example, we show theoretically that the field ionization asymmetry induced by cosine few cycle pulses is strongly enhanced using temporally superresolved laser pulses.