ABSTRACT
We report measurements concerning the propagation of femtosecond laser pulses in fused silica with a wavelength at 1.9 µm falling in the negative group velocity dispersion region. Under sub-GW excitation power, stable filaments are observed over several cm showing the emergence of nonspreading pulses both in space and time. At higher excitation powers, one observes first multiple pulse splitting followed by the emergence of the quasispatiotemporal solitary filament. These results are well reproduced by numerical simulations.
ABSTRACT
We demonstrate for the first time (to our knowledge) characterization of ultrashort IR pulses by self-referenced spectral interferometry. Both sub-55-fs pulses from 1.4 µm to 2 µm and broadband 2.5-cycle pulses at 1.65 µm (13 fs FWHM) are characterized.
ABSTRACT
We explore theoretically and numerically the temporal contrast limitation of a self-referenced spectral interferometry measurement. An experimental confirmation is given by characterization and fine compression of hollow-core fiber generated sub-15 fs pulses, yielding an accurately measured coherent contrast of 50 dB on a ±400 fs time range.
