All-optical Control of the Propagation of Intense Laser Light in   Condensed Media
  We experimentally demonstrate optical control of filamentation that occurs during propagation of intense, ultrashort laser pulses through crystals like barium fluoride and sapphire. Control is exercised by rotating the plane of polarization of the incident laser radiation and is demonstrated by directly visualizing filamentation in the bulk via six-photon absorption-induced fluorescence and, concomitantly, by probing the spectral and spatial properties of white light that is generated. 
A. K. Dharmadhikari, K. Alti, J. A. Dharmadhikari, and D. Mathur