|
|||||
|
|
Controlling a bunch of multiple filaments by means of a beam diameter |
|
| Authors: | OG Kosareva NA Panov N Akozbek VP Kandidov Q Luo SA Hosseini W Liu J-F Gravel G Roy SL Chin |
| Institution: | (1) International Laser Center, Physics Department, M.V. Lomonosov Moscow State University, Moscow, 119992, Russia;(2) Time Domain Corporation, Cummings Research Park, 7057 Old Madison Pike, Huntsville, AL 35806, USA;(3) Centre d’Optique, Photonique et Laser (COPL) et Département de Physique, de Génie Physique et d’Optique, Université Laval, Québec, QC, G1K 7P4, Canada;(4) Defense Research and Development Canada-Valcartier (DRDC-Valcartier), Val-Belair, QC, G3J 1X5, Canada |
| Abstract: | We demonstrate a three orders of magnitude increase and stability in the backscattered fluorescence signal from nitrogen molecules by terawatt femtosecond laser pulse induced air filaments using a new method. The method is based on squeezing the initial beam diameter using a telescope. The effect of laser shot-to-shot fluctuations was included in numerical simulations by a random distribution of the initial intensity in both squeezed and non-squeezed beams. Statistical processing of the simulation results shows that the average diameter of plasma channels as well as the total amount of free electrons generated in a bunch of multiple filaments in air is larger in the squeezed beam. Shot-to-shot stability of the simulated plasma density increases in the squeezed beam. The change of this plasma density with propagation distance is in good qualitative agreement with the change of the range-corrected nitrogen fluorescence signal with distance. PACS 42.65.Jx; 42.60.Jf; 42.68.Ay; 42.68.Wt |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ | |