Broadening of white-light continuum by filamentation in BK7 glass at its zero-dispersion point

• We observed the white-light continuum by filamentation at the zero-dispersion point.
• Peak power significantly exceeding the critical value of self-focusing was used.
• Wider spectral broadening was obtained around the zero-dispersion point.

Broadening of white-light continuum is observed by filamentation of near-infrared femtosecond laser pulses with peak power exceeding the megawatt level in BK7 glass with the presence of the zero-dispersion point. The simulated results show that, due to the low dispersion at the zero-dispersion point, the broadening of white-light continuum can be wider and the filament can persist in propagating stably longer distance.