Applied Physics B

, Volume 77, Issue 2, pp 167–170

Evolution of a super-broadened spectrum in a filament generated by an ultrashort intense laser pulse in fused silica

Regular Paper

DOI: 10.1007/s00340-003-1176-9

Cite this article as:
Fang, XJ. & Kobayashi, T. Appl Phys B (2003) 77: 167. doi:10.1007/s00340-003-1176-9

Abstract

We report experimental and theoretical investigations of the evolution of super-broadened spectrum generation by intense 50-fs pulses propagating in bulk fused silica. Based on good agreement between the experimental results and numerical simulations, a mechanism of supercontinuum generation (SCG) is proposed. At first, both self-phase modulation (SPM) and stimulated Raman scattering (SRS) contribute substantially but slowly to the broadening before filament formation takes place. After filamentation, a plasma grows rapidly and asymmetric spectral broadening results in a blue-shifted spectrum extending to about 400 nm. A time-resolved experiment of the SCG was also performed using a double-pump technique. The temporal behavior suggests that the vibrational mode excited by the stimulated Raman process by the first pulse contributes to the occurrence of self-focusing.

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  1. 1.Department of Physics, Faculty of ScienceUniversity of TokyoTokyoJapan