Author(s): Francis Théberge, Marc Châteauneuf, Gilles Roy, Pierre Mathieu, and Jacques Dubois
Tunable far-infrared laser pulses were generated efficiently during two-color filamentation in air. Understanding the creation of few-cycle far-infrared laser pulses is important since it is at the frontier between two possible generation mechanisms. The first one is the four-wave mixing generation,...
[Phys. Rev. A 81, 033821] Published Thu Mar 11, 2010
Physical Review A
Generation of tunable and broadband far-infrared laser pulses during two-color filamentation
Thu, 2010-03-11 02:00 — GuestTransient low-frequency fluctuations in semiconductor lasers with optical feedback
Thu, 2010-03-11 02:00 — GuestAuthor(s): J. Zamora-Munt, C. Masoller, and J. García-Ojalvo
Time-delayed systems often exhibit multistability of coexisting attractors, which can result in long chaotic transients on the way to one of the coexisting states. Strong enough noise can transform this transient chaos into noise-sustained dynamics. Here we study the interplay between delay-induced ...
[Phys. Rev. A 81, 033820] Published Thu Mar 11, 2010
Filamentation-induced third-harmonic generation in air via plasma-enhanced third-order susceptibility
Wed, 2010-03-10 02:00 — GuestAuthor(s): S. Suntsov, D. Abdollahpour, D. G. Papazoglou, and S. Tzortzakis
We study, both experimentally and theoretically, the underlying physics of third-harmonic generation in air by a filamented infrared femtosecond laser pulse propagating through a thin plasma channel. It is shown that the recently observed more than two-order-of-magnitude increase of the efficiency o...
[Phys. Rev. A 81, 033817] Published Wed Mar 10, 2010
Laser-catalyzed spin-exchange process in a Bose-Einstein condensate
Mon, 2010-03-08 02:00 — GuestAuthor(s): H. Jing, Y. Jiang, Weiping Zhang, and P. Meystre
We show theoretically that it is possible to optically control collective spin-exchange processes in spinor Bose condensates through virtual photoassociation. The interplay between optically induced spin exchange and spin-dependent collisions provides a flexible tool for the control of atomic spin d...
[Phys. Rev. A 81, 031603] Published Mon Mar 08, 2010
Spatiotemporal polarization gradients in phase-bearing light
Mon, 2010-03-08 02:00 — GuestAuthor(s): V. E. Lembessis and M. Babiker
It is shown how the interference of two circularly polarized laser beams endowed with orbital angular momentum can give rise to spatial and temporal polarization gradients, displaying axial as well as angular symmetry properties. Illustrations are given with reference to circularly polarized Laguerr...
[Phys. Rev. A 81, 033811] Published Mon Mar 08, 2010
Two-dimensional atom localization in a four-level tripod system in laser fields
Mon, 2010-03-08 02:00 — GuestAuthor(s): Vladimir Ivanov and Yuri Rozhdestvensky
We propose a scheme for two-dimensional (2D) atom localization in a four-level tripod system under an influence of two orthogonal standing-wave fields. Position information of the atom is retained in the atomic internal states by an additional probe field either of a standing or of a running wave. I...
[Phys. Rev. A 81, 033809] Published Mon Mar 08, 2010
Photoassociation spectra and the validity of the dipole approximation for weakly bound dimers
Mon, 2010-03-08 02:00 — GuestAuthor(s): Daniel G. Cocks and Ian B. Whittingham
Photoassociation (PA) of ultracold metastable helium to the 2s2p manifold is theoretically investigated using a nonperturbative close-coupled treatment in which the laser coupling is evaluated without assuming the dipole approximation. The results are compared with our previous study [D. G. Cocks an...
[Phys. Rev. A 81, 033406] Published Mon Mar 08, 2010
Lifetimes and branching ratios of excited states in La^{-} , Os^{-} , Lu^{-} , Lr^{-} , and Pr^{-}
Fri, 2010-03-05 02:00 — GuestAuthor(s): Steven M. O’Malley and Donald R. Beck
Relativistic configuration-interaction calculations have been performed for all possible E1, M1, and E2 transitions between bound anion states of La^{-} and Os^{-} . We pay particular attention to E1 transitions in each case that may be of use in laser cooling of these anions. Although the La^{-} tr...
[Phys. Rev. A 81, 032503] Published Fri Mar 05, 2010
Dynamics of strong-field laser-induced microplasma formation in noble gases
Thu, 2010-03-04 02:00 — GuestAuthor(s): D. A. Romanov, R. Compton, A. Filin, and R. J. Levis
The ultrafast dynamics of microplasmas generated by femtosecond laser pulses in noble gases has been investigated using four-wave mixing (FWM). The time dependence of the FWM signal is observed to reach higher intensity levels faster for Xe, with progressively lower scattering intensity and longer t...
[Phys. Rev. A 81, 033403] Published Thu Mar 04, 2010
Optical injection in semiconductor ring lasers
Thu, 2010-03-04 02:00 — GuestAuthor(s): W. Coomans, S. Beri, G. Van der Sande, L. Gelens, and J. Danckaert
We theoretically investigate optical injection in semiconductor ring lasers and disclose several dynamical regimes. Through numerical simulations and bifurcation continuation, two separate parameter regions in which two different injection-locked solutions coexist are revealed, in addition to a regi...
[Phys. Rev. A 81, 033802] Published Thu Mar 04, 2010
