Enhancing electric or magnetic multipole responses in the absorption of superimposed Bessel beams C Iorga, V Baran, M Boca, Y Xu, D L Balabanski Physica Scripta, 2025 This paper theoretically investigates the photon-absorption of superimposed Bessel Beams with identical total angular momentum m γ but opposite spin helicities. We derive simple expressions in terms of pitch angle for the beam weights enabling a selection of either electric or magnetic multipole of rank L = ∣m γ ∣ near the vertex by setting the superimposed beams in phase or anti-phase, respectively. The selection rules are then relaxed by accounting for an impact parameter and the calculations are extended for macroscopic targets. The enhancement of electric multipoles are quite robust to the relative phase of the superimposed Bessel beams, while the magnetic types reach a maximum when the beams are in anti-phase and a minimum when in phase, respectively. These results are useful in proposing experiments for measuring electromagnetic multipole responses of higher order in molecules, atoms and nuclei.
Coherent nonlinear Thomson scattering of Laguerre-Gauss beams on an electron sheet Petru-Vlad Toma, Andrei Cristian Opinca, Virgil Baran, Madalina Boca Physical Review A, 2025 We present a study of the scattering of a monochromatic helical laser beam, described by a Laguerre-Gauss solution of the Maxwell equations, on an electron sheet, initially at rest in the focal plane of the laser; the interaction is described in the framework of a local plane wave approximation. We calculate the scattered electromagnetic field observed in an arbitrary point at a large distance from the laser focal spot, by adding coherently the contributions of each electron in the electron sheet. Due to the interference effects, the radiation is emitted only into the forward direction, within a narrow cone, and it has a spatial structure that we analyze theoretically and numerically. For circularly polarized incident fields, the structure is also helical, with a helical index which depends on the helical index of the incident radiation and the harmonic order. These structures can be observed experimentally, as each harmonic order is emitted with a different frequency, and within cones of different opening angles. Our findings are in agreement with experimental results in the literature which demonstrate the generation of OAM carrying photons by radiation scattering on electrons.
Angular momentum transfer to charged particles by interaction with Laguerre-Gauss pulses Petru-Vlad Toma, Sebastian Micluţa-Câmpeanu, Mădălina Boca, Virgil Băran Aip Advances, 2024 Orbital angular momentum of light and the associated Laguerre–Gauss modes have garnered increasing interest due to the many applications they promise in the fields of telecommunications and quantum information, as well as charged particle acceleration. Here, we use the numerical simulation of the dynamics of a large number of identical, charged, relativistic, but classical particles, forming a statistical ensemble and seen as test-particles in a time-dependent external electromagnetic field, to get insight into the process of a head-on collision with a pulsed Laguerre–Gauss mode. We have identified two steady-states regimes (low a0 and large a0), where the distribution of the final angular momentum gained by the particles as a function of their initial coordinates is well-behaved and does not change its structure with variations of the reduced amplitude. For small reduced amplitudes a0 of the incoming electromagnetic field, we have also found an analytic approximation of the expression for the angular momentum transferred to the particles after the pulse has left their region. Using both numerical integration and the analytic approximation, we have investigated the effects of the field’s gradient, initial phase of the field, polarization type, and azimuthal order m.
Linear and Angular Momentum of Classical Particles Interacting with a Laguerre-Gauss Laser Pulse Petru-Vlad Toma, Virgil Băran, Sebastian Micluta-Campeanu, Madalina Boca Journal of Physics Conference Series, 2024 We investigate the evolution of an ensemble of classical charged particles interacting with a Laguerre-Gauss laser pulse. We integrate numerically the relativistic equations of motion for the particles which at the initial moment (before the arrival of the laser pulse) are at rest, distributed uniformly in a disk in the focal plane of the laser. We study the evolution in time of the linear and the angular momentum of the particles, and its dependence on the laser parameters (radial and azimuthal indices of the LG mode, waist, duration, and intensity) and also on the initial position of the particle in the focal plane. We show that in the low-intensity regime, the net transfer of linear momentum is parallel to the focal plane, while at large intensities the dominant component of the momentum is along the laser propagation direction. We also identify scaling laws obeyed by the net transfer of linear and angular momentum to the particles as a function of the field intensity. We present the relativistic ponderomotive force approximation model and study its validity for different parameters of the laser field. The scaling laws mentioned above are discussed also in the context of this approximation.
Angular distribution and polarization properties of radiation scattering in the classical framework Madalina Boca Aip Conference Proceedings, 2017 We study the scattering of intense electromagnetic radiation on free relativistic electrons in the classical formalism. Starting from the well known property that in the relativistic regime the radiation is emitted by an accelerated charged particle along its instantaneous velocity direction we discuss the effects of the radiation reaction on the shape of the angular distribution in Thomson effect for the case of linear and circular polarization of the incident light and for different collision geometries. We also study the polarization properties of the emitted radiation for several low intensity cases.
Photon polarization in Compton scattering: Pulse shape effects M Boca, C Stoica, A Dumitriu, V Florescu Journal of Physics Conference Series, 2015 We study in the framework of quantum electrodynamics the scattering of a plane wave electromagnetic field on free electrons in the low intensity limit. We derive analytic formulas describing the polarization properties of the emitted photons. We discuss and illustrate with a numerical example the effects of the electromagnetic pulse duration on their polarization.
Mott scattering of a Klein-Gordon particle in an intense laser field Madalina Boca Central European Journal of Physics, 2013 We study the Mott scattering of charged spinless particles in the presence of an intense plane wave laser pulse with fixed propagation direction and arbitrary duration and shape. We derive two equivalent forms of the transition amplitude and we discuss the relation between the respective results obtained in the case of a laser pulse and the monochromatic case. We obtain the condition defining the boundaries of the “bright” domain (the domain of allowed values in the energy-direction space of the scattered particle) and we illustrate our results with numerical examples.
Mott scattering in the presence of an intense laser field Romanian Reports in Physics, 2013
Electron distributions in nonlinear Compton scattering Madalina Boca, Victor Dinu, Viorica Florescu Physical Review A Atomic Molecular and Optical Physics, 2012 Based on quantum theory, we investigate the distribution of the electrons scattered in the nonlinear Compton effect by an electromagnetic plane wave. The monochromatic case, examined in detail, reveals features of the electron distribution that are useful in the understanding of the pulsed plane-wave case for particular intensity and electron energy regimes. The graphs displayed focus on the case of a head-on or nearly head-on collision of an energetic electron with an electromagnetic circularly polarized pulsed plane wave and show that the deviation in direction is extremely small, while the distribution in energy can be visibly different from that of the initial electron. Two pulse shapes, several laser intensities, and high incident electron energies are considered.
A relativistic simulator in python MA Boboaca, M Boca EPJ Web of Conferences 365, 07006 , 2026 2026
Classical and Quantum Description of the Kapitza-Dirac Effect DM Banu, RA Radu, M Boca EPJ Web of Conferences 365, 08001 , 2026 2026
Enhancing electric or magnetic multipole responses in the absorption of superimposed Bessel beams C Iorga, V Baran, M Boca, Y Xu, DL Balabanski Physica Scripta 100 (6), 065306 , 2025 2025
Coherent nonlinear Thomson scattering of Laguerre-Gauss beams on an electron sheet PV Toma, AC Opinca, V Baran, M Boca Physical Review A 111 (1), 013101 , 2025 2025 Citations: 2
Linear and Angular Momentum of Classical Particles Interacting with a Laguerre-Gauss Laser Pulse PV Toma, V Băran, S Micluta-Campeanu, M Boca Journal of Physics: Conference Series 2894 (1), 012006 , 2024 2024
Angular momentum transfer to charged particles by interaction with Laguerre–Gauss pulses PV Toma, S Micluţa-Câmpeanu, M Boca, V Băran AIP Advances 14 (6) , 2024 2024 Citations: 4
Scaling properties of angular momentum transfer to charged particles under Laguerre-Gauss laser pulse PV Toma, S Micluţa-Câmpeanu, M Boca, A Nicolin, V Băran PROCEEDINGS OF THE TIM20-21 PHYSICS CONFERENCE 2843 (1), 020005 , 2023 2023
Angular distribution and polarization properties of radiation scattering in the classical framework M Boca AIP Conference Proceedings 1852 (1), 040003 , 2017 2017 Citations: 1
Photon polarization in Compton scattering: pulse shape effects M Boca, C Stoica, A Dumitriu, V Florescu Journal of Physics: Conference Series 594 (1), 012014 , 2015 2015 Citations: 1
Mott scattering of a Klein-Gordon particle in an intense laser field M Boca Central European Journal of Physics 11 (9), 1123-1134 , 2013 2013 Citations: 6
Mott scattering in the presence of an intense laser field M Boca Rom. Rep. Phys 65, 1246-1257 , 2013 2013 Citations: 4
Electron distribution in nonlinear Compton scattering V Dinu, M Boca, V Florescu Journal of Physics: Conference Series 388 (3), 032018 , 2012 2012
Electron distributions in nonlinear Compton scattering M Boca, V Dinu, V Florescu Physical Review A—Atomic, Molecular, and Optical Physics 86 (1), 013414 , 2012 2012 Citations: 30
Spin effects in nonlinear Compton scattering in a plane-wave laser pulse M Boca, V Dinu, V Florescu Nuclear Instruments and Methods in Physics Research Section B: Beam … , 2012 2012 Citations: 30
Generalized space-translated Dirac and Pauli equations for superintense laser-atom interactions M Boca, V Florescu, M Gavrila Physical Review A—Atomic, Molecular, and Optical Physics 85 (2), 023425 , 2012 2012 Citations: 4
On the properties of the Volkov solutions of the Klein–Gordon equation M Boca Journal of Physics A: Mathematical and Theoretical 44 (44), 445303 , 2011 2011 Citations: 33
Thomson scattering in the high intensity regime M Boca, A Oprea Physica Scripta 83 (5), 055404 , 2011 2011 Citations: 24
Thomson and Compton scattering with an intense laser pulse M Boca, V Florescu The European Physical Journal D 61 (2), 449-462 , 2011 2011 Citations: 53
Nonlinear Compton scattering with a laser pulse (vol 80, 053403, 2009) M Boca, V Florescu PHYSICAL REVIEW A 81 (3) , 2010 2010
Erratum: Nonlinear Compton scattering with a laser pulse [Phys. Rev. A 80 , 053403 (2009)] M Boca, V Florescu Physical Review A—Atomic, Molecular, and Optical Physics 81 (3), 039901 , 2010 2010 Citations: 4
MOST CITED SCHOLAR PUBLICATIONS
Nonlinear Compton scattering with a laser pulse M Boca, V Florescu Physical Review A—Atomic, Molecular, and Optical Physics 80 (5), 053403 , 2009 2009 Citations: 238
Thomson and Compton scattering with an intense laser pulse M Boca, V Florescu The European Physical Journal D 61 (2), 449-462 , 2011 2011 Citations: 53
The completeness of Volkov spinors M Boca, V Florescu Rom. J. Phys 55 (5), 511 , 2010 2010 Citations: 37
On the properties of the Volkov solutions of the Klein–Gordon equation M Boca Journal of Physics A: Mathematical and Theoretical 44 (44), 445303 , 2011 2011 Citations: 33
Electron distributions in nonlinear Compton scattering M Boca, V Dinu, V Florescu Physical Review A—Atomic, Molecular, and Optical Physics 86 (1), 013414 , 2012 2012 Citations: 30
Spin effects in nonlinear Compton scattering in a plane-wave laser pulse M Boca, V Dinu, V Florescu Nuclear Instruments and Methods in Physics Research Section B: Beam … , 2012 2012 Citations: 30
From the UV to the static-field limit: rates and scaling laws of intense-field ionization of helium JS Parker, GSJ Armstrong, M Boca, KT Taylor Journal of Physics B: Atomic, Molecular and Optical Physics 42 (13), 134011 , 2009 2009 Citations: 29
Thomson scattering in the high intensity regime M Boca, A Oprea Physica Scripta 83 (5), 055404 , 2011 2011 Citations: 24
Quantum Chernoff bound as a measure of nonclassicality for one-mode Gaussian states M Boca, I Ghiu, P Marian, TA Marian arXiv preprint arXiv:0806.1892 , 2008 2008 Citations: 24
Dynamic stabilization of ground-state hydrogen in superintense circularly polarized laser pulses M Boca, HG Muller, M Gavrila Journal of Physics B: Atomic, Molecular and Optical Physics 37 (1), 147-163 , 2004 2004 Citations: 20
Mott scattering of a Klein-Gordon particle in an intense laser field M Boca Central European Journal of Physics 11 (9), 1123-1134 , 2013 2013 Citations: 6
Relativistic effects in the time evolution of an one-dimensional model atom in a laser pulse M Boca, V Florescu The European Physical Journal D 46 (1), 15-20 , 2008 2008 Citations: 6
Resonances and antibound states for the dressed one-dimensional δ-function potential M Boca, C Chirilã, M Stroe, V Florescu Physics Letters A 286 (6), 410-417 , 2001 2001 Citations: 6
Angular momentum transfer to charged particles by interaction with Laguerre–Gauss pulses PV Toma, S Micluţa-Câmpeanu, M Boca, V Băran AIP Advances 14 (6) , 2024 2024 Citations: 4
Mott scattering in the presence of an intense laser field M Boca Rom. Rep. Phys 65, 1246-1257 , 2013 2013 Citations: 4
Generalized space-translated Dirac and Pauli equations for superintense laser-atom interactions M Boca, V Florescu, M Gavrila Physical Review A—Atomic, Molecular, and Optical Physics 85 (2), 023425 , 2012 2012 Citations: 4
Erratum: Nonlinear Compton scattering with a laser pulse [Phys. Rev. A 80 , 053403 (2009)] M Boca, V Florescu Physical Review A—Atomic, Molecular, and Optical Physics 81 (3), 039901 , 2010 2010 Citations: 4
Comment on “Origin of light-induced states in intense laser fields and their observability in photoelectron spectra” M Stroe, M Boca Physical Review A—Atomic, Molecular, and Optical Physics 71 (1), 017401 , 2005 2005 Citations: 3
Coherent nonlinear Thomson scattering of Laguerre-Gauss beams on an electron sheet PV Toma, AC Opinca, V Baran, M Boca Physical Review A 111 (1), 013101 , 2025 2025 Citations: 2
The dressed states of an electron in a one-dimensional two-functions potential C Chirila, M Boca, V Dinu, V Florescu The European Physical Journal D-Atomic, Molecular, Optical and Plasma … , 2003 2003 Citations: 2
