Abstract
We have numerically investigated the supercontinuum generation by a femtosecond annular Gaussian beam in air. Compared with the spectra broadening of the Gaussian filament under the same initial condition, the smooth supercontinuum spectra of the annular Gaussian filament are wide enough to cover the whole visible frequency range in the first focusing cycle. The spectra broadening is analyzed from the frequency shift induced by the ionization and the self-phase modulation. For the blue side of the enhancement of the spectra broadening, the ionization-induced and intensity-induced frequency shifts play the dominant role in the onset distance of the filament and the first maximum value of the spectra broadening, respectively. Then, we have also discussed the influences of the initial pulse energy and the spatial chirp for wide and smooth supercontinuum spectra to cover the whole visible frequency range. Therefore, it is an efficient route to produce the supercontinuum spectra by the annular Gaussian beam.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
