Dynamics of Stabilized Optical and Plasma Filaments Generated During Propagation of a High Power Laser Pulse in Air

Recently, the self-focusing dynamics of high-power, ultrashort laser pulses has attracted significant attention, particularly for the case in which high-power pulses propagate in air. The resulting long-distance filamentation behavior has been exploited for remote sensing in the atmosphere. The dynamic balance between Kerr self-focusing and defocusing due to plasma generation may be affected by the laser beam noise, inducing multiple filamentation (MF). We will describe our investigations on control of beam breakup into multiple filaments and methods for generation of a single filament. The experiments were carried using both .low. and .high. quality beams. We also investigated the power scaling for the beam collapse and demonstrate that the difference in the collapse dynamics between .low-power (PcriiPiiPMF) and .high-power (PiiPMF) beams is due to the effect of input beam noise.