We experimentally demonstrate an efficient way to control and stabilize single optical filaments initiated by ultrashort laser pulses in a rare gas medium. This is done by the application of a stationary two-dimensional phase mask to the laser beam prior to focusing. Simple circular phase-step patterns of a given radius and relative phase are sufficient to stabilize the pointing of the filament output and to optimize the spectral bandwidth of the light without any resulting loss of input laser power.
© 2006 Optical Society of America
Original Manuscript: February 21, 2006
Revised Manuscript: May 17, 2006
Manuscript Accepted: May 18, 2006
Published: July 10, 2006
Thomas Pfeifer, Lukas Gallmann, Mark J. Abel, Daniel M. Neumark, and Stephen R. Leone, "Circular phase mask for control and stabilization of single optical filaments," Opt. Lett. 31, 2326-2328 (2006)