We report on the postfilamentation behavior of a Stokes pulse created from intense and collimated ultrashort pulses propagating in air. A systematic analysis of the pulse propagation revealed that the redshifted Raman pulse produced during filamentation had a larger divergence than the postfilamentation intense pump pulse. Also, the analysis of the far-field Stokes transverse ring revealed that the intensity in this ionization-free light channel is still sufficiently high to induce stimulated Raman scattering after ionization had ended. This behavior further extends the potential of filamentation to remotely induce third-order nonlinearities.
© 2011 Optical Society of America
Atmospheric and Oceanic Optics
Original Manuscript: June 2, 2011
Manuscript Accepted: August 8, 2011
Published: November 16, 2011
Jean-François Daigle, Tie-Jun Wang, Sima Hosseini, Shuai Yuan, Gilles Roy, and See Leang Chin, "Dynamic behavior of postfilamentation Raman pulses," Appl. Opt. 50, 6234-6238 (2011)