Nonlinear to geometric focusing transition: beam self-cleaning and self-focusing critical power

被引:1
作者
Pushkarev, D. V. [1 ]
Rizaev, G. E. [1 ]
Seleznev, L. V. [1 ]
机构
[1] Russian Acad Sci, PN Lebedev Phys Inst, 53 Leninskiy Prospect, Moscow 119991, Russia
关键词
FEMTOSECOND LASER-PULSE; REFRACTIVE-INDEX; FILAMENTATION; AIR; SUPERCONTINUUM; BREAKDOWN; LIGHT;
D O I
10.1364/JOSAB.525801
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
We propose an easy but effective approach to find a transition numerical aperture between the regimes of laser pulse filamentation with nonlinear focusing and with geometric focusing predominance. The suggested method based on the beam profile measurements allows correction of the data provided by spectra measurements. Using a simple semi-analytical model, we study the dependence of the transition numerical aperture on the pulse power and medium nonlinearity. The analysis shows that in condensed media the transition from the nonlinear to geometric focusing regime occurs at much tighter focusing than in air. Moreover, if the medium nonlinear refractive index is high enough, only the nonlinear focusing regime is observed even at numerical apertures close to one, which allows symmetric plasma channel formation. (c) 2024 Optica Publishing Group
引用
收藏
页码:1732 / 1738
页数:7
相关论文
共 45 条
[1]  
Akhmanov S. A., 1997, Physical Optics.
[2]  
Akhmanov S. A., 1992, Optics of Femtosecond Laser Pulses
[3]  
[Anonymous], 1967, IVUZ Radiofiz.
[4]   SELF-CHANNELING OF HIGH-PEAK-POWER FEMTOSECOND LASER-PULSES IN AIR [J].
BRAUN, A ;
KORN, G ;
LIU, X ;
DU, D ;
SQUIER, J ;
MOUROU, G .
OPTICS LETTERS, 1995, 20 (01) :73-75
[5]  
Cerami Loren., 2013, Ultrafast nonlinear optics, P287, DOI [10.1007/978-3-319-00017-6_12, DOI 10.1007/978-3-319-00017-6_12]
[6]   Observation of filamentation-induced continuous self-frequency down shift in air [J].
Chen, Y. ;
Theberge, F. ;
Marceau, C. ;
Xu, H. ;
Akoezbek, N. ;
Kosareva, O. ;
Chin, S. L. .
APPLIED PHYSICS B-LASERS AND OPTICS, 2008, 91 (02) :219-222
[7]   SELF-TRAPPING OF OPTICAL BEAMS [J].
CHIAO, RY ;
GARMIRE, E ;
TOWNES, CH .
PHYSICAL REVIEW LETTERS, 1964, 13 (15) :479-&
[8]   Refractive index of air: New equations for the visible and near infrared [J].
Ciddor, PE .
APPLIED OPTICS, 1996, 35 (09) :1566-1573
[9]   Femtosecond filamentation in transparent media [J].
Couairon, A. ;
Mysyrowicz, A. .
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 2007, 441 (2-4) :47-189
[10]   Micromachining of photonic devices by femtosecond laser pulses [J].
Della Valle, G. ;
Osellame, R. ;
Laporta, P. .
JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS, 2009, 11 (01)