Measurement of the Superluminal Group Velocity of an Ultrashort Bessel Beam Pulse

I. Alexeev; K. Y. Kim; H. M. Milchberg

doi:10.1103/PhysRevLett.88.073901

Measurement of the Superluminal Group Velocity of an Ultrashort Bessel Beam Pulse

I. Alexeev, K. Y. Kim, and H. M. Milchberg

Phys. Rev. Lett. 88, 073901 – Published 31 January 2002

Abstract

The superluminal group velocity of an ultrashort optical Bessel beam pulse is measured over its entire depth of field, corresponding to $\sim 2 \times 10^{4}$ optical wavelengths. The method used is to measure the traveling ionization front induced by the pulse.