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Related papers: Harmonic generation and filamentation: when second…

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We present a theoretical study of high-order harmonic generation (HHG) and propagation driven by an infrared field carrying orbital angular momentum (OAM). Our calculations unveil the following relevant phenomena: extreme-ultraviolet…

Optics · Physics 2015-07-03 C. Hernández-García , A. Picón , J. San Román , L. Plaja

Various interference effects are known to exist in the process of high harmonic generation (HHG) both at the single atom and macroscopic levels. In particular, the quantum path difference between the long and short trajectories of electron…

Spatial and spectral properties of the pulsed second harmonic generation in a periodically-poled KTP waveguide exploiting simultaneously the first, second, and third harmonics of periodic nonlinear modulation are analyzed. Experimental…

Quantum Physics · Physics 2013-01-30 Radek Machulka , Jiří Svozilík , Jan Soubusta , Jan Peřina , Ondřej Haderka

We study numerically the interaction between an intense circularly polarized laser field and an electron moving in a potential which has a discrete cylindrical symmetry with respect to the laser pulse propagation direction. This setup…

Atomic Physics · Physics 2009-11-07 F. Ceccherini , D. Bauer

Time-dependent nonlinear media, such as rapidly generated plasmas produced via laser ionization of gases, can increase the energy of individual laser photons and generate tunable high-order harmonic pulses. This phenomenon, known as photon…

Second harmonic generation is a powerful tool directly connected to the symmetry of materials. Phase transitions, lattice rotations or electromagnetic coupling in multiferroic compounds can be revealed by using second harmonic…

Optics · Physics 2010-01-11 Pablo Molina , Mariola O Ramirez , Basilio J. Garcia , Luisa E. Bausa

We generate high-order harmonics in gaseous medium with tunable photon energy using time domain interferometry of double pulses in a non-collinear generation geometry. The method is based on the fact that the generated harmonics inherit…

We investigate the reversibility of laser filamentation, a self-sustained, non-linear propagation regime including dissipation and time-retarded effects. We show that even losses related to ionization marginally affect the possibility of…

Optics · Physics 2014-09-04 Nicolas Berti , Wahb Ettoumi , Jérôme Kasparian , Jean-Pierre Wolf

The absence of ionization and observation of white continuum in the initial moment of filamentation of powerful femtosecond laser pulses, propagating in silica glasses, as well as the filamentation without plasma channels observed in the…

Optics · Physics 2016-12-28 L. M. Kovachev , D. A. Georgieva , N. Nedyalkov

We investigate a two-level atom in the field of a strong laser pulse. The resulting time-dependent polarization is the source of a radiation the frequency components of which are essentially harmonics of the driving field's carrier…

Quantum Physics · Physics 2016-09-13 Ákos Gombkötő , Attila Czirják , Sándor Varró , Péter Földi

Second and third harmonic generation in the opaque region of a GaAs wafer is experimentally observed both in transmission and reflection. These harmonic components can propagate through an opaque material as long as the pump is tuned to a…

Optics · Physics 2019-05-13 L. Rodriguez , J. Trull , M. Scalora , R. Vilaseca , C. Cojocaru

Broadband laser sources based on supercontinuum generation by femtosecond laser filamentation have enabled applications from stand-off sensing and spectroscopy to the generation and self-compression of high-energy few-cycle pulses.…

Second-harmonic emission at a frequency that is twice the laser frequency is an important diagnostic for nonlinear laser-plasma interaction. It is forbidden for centrosymmetric materials such as the bulk of sapphire. The symmetry, however,…

We study the photon statistics of weak coherent pulses propagating through a cold Rydberg atomic ensemble in the regime of Rydberg electromagnetically induced transparency. We show experimentally that the value of the second-order…

Using numerical simulations, we study propagation of ultrashort light pulses in an inhomogeneously broadened two-level medium. There are two main issues in our study. The first one concerns the transient process of self-induced transparency…

Optics · Physics 2015-05-05 Denis Novitsky

Theoretical investigation is conducted of high-order harmonic generation (HHG) in silicon thin films to elucidate the effect of light propagation in reflected and transmitted waves. The first-principles simulations are performed of the…

Materials Science · Physics 2023-01-23 Shunsuke Yamada , Tomohito Otobe , David Freeman , Anatoli Kheifets , Kazuhiro Yabana

We investigate the interplay of diffraction and nonlinear effects during propagation of very short light pulses. Adapting the factorization approach to the problem at hand by keeping the transverse-derivative terms apart from the residual…

Optics · Physics 2016-02-17 C. L. Korpa , Gy. Toth , J. Hebling

We theoretically investigate the interference effect of high-order harmonics generated from molecules at different alignment angles. It is shown that the interference of the harmonic emissions from molecules aligned at different angles can…

Optics · Physics 2015-02-27 Meiyan Qin , Xiaosong Zhu , Yang Li , Qingbin Zhang , Pengfei Lan , Peixiang Lu

High harmonic generation due to the interaction of a short ultra relativistic laser pulse with overdense plasma is studied analytically and numerically. On the basis of the ultra relativistic similarity theory we show that the high harmonic…

Plasma Physics · Physics 2009-11-11 T. Baeva , S. Gordienko , A. Pukhov

Resonant enhancement of high harmonic generation can be obtained in plasmas containing ions with strong radiative transitions resonant with harmonic orders. The mechanism for this enhancement is still debated. We perform the first temporal…