Self-Focusing and Waveguide Propagation in a Plasma

Litvak, A. G.

doi:10.1070/pu1973v015n04abeh005017

Cited by 38 publications

(59 citation statements)

References 6 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such BECs, inherently have a spatially nonlocal nonlinear response due to the finite range of the inter-particle interaction potential. Spatial nonlocality, which is already an established concept in plasma physics [5,6,7], means that the response of the medium at a particular point is not determined solely by the wave intensity at that point (as in local media), but also depends on the wave intensity in its vicinity. The nonlocal nature often results from a transport process, such as atom diffusion [8], heat transfer [9,10] or drift of electric charges [11].…”

Section: Introductionmentioning

confidence: 99%

Modulational instability, solitons and beam propagation in spatially nonlocal nonlinear media

Królikowski

Bang

Nikolov

et al. 2004

J. Opt. B: Quantum Semiclass. Opt.

399

322

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Modulational instability, solitons and beam propagation in spatially nonlocal nonlinear media

Królikowski

Bang

Nikolov

et al. 2004

J. Opt. B: Quantum Semiclass. Opt.

399

322

View full text Add to dashboard Cite

show abstract

“…It is important to notice that in contrast to the conventional nonlocal NLS equation describing, e.g., materials with a thermal [17] or diffusion [18] type nonlinearity, liquid crystals [19], and photorefractive crystals [20], the nonlocal response of the χ (2) system depends on the square of the FW, not its intensity. Thus the phase of the FW enters into the picture and one cannot directly transfer the known nonlocal stability results for plane waves [14,16] and solitons [13,15].…”

mentioning

confidence: 99%

Quadratic solitons as nonlocal solitons

et al. 2003

View full text Add to dashboard Cite

show abstract

“…Nonlocality is often the consequence of transport processes which include atom or heat diffusion in atomic vapors [9], plasma [10] and thermal media [11], or charge drift in photorefractive crystals [12]. In addition long range interactions are responsible for a nonlocal response in liquid crystals [13] or dipolar Bose Einstein condensates [14].…”

mentioning

confidence: 99%

Nonlocal Stabilization of Nonlinear Beams in a Self-Focusing Atomic Vapor

2007

View full text Add to dashboard Cite

We show that ballistic transport of optically excited atoms in an atomic vapor provides a nonlocal nonlinearity which stabilizes the propagation of vortex beams and higher order modes in the presence of a self-focusing nonlinearity. Numerical experiments demonstrate stable propagation of lowest and higher order vortices over a hundred diffraction lengths, before dissipation leads to decay of these structures.PACS numbers: 42.65. Tg,42.65.Sf, The propagation and dynamics of localized nonlinear waves is a subject of great interest in a range of physical settings stretching from nonlinear optics to plasmas and ultracold atomic gases [1,2]. The structure and stability of nonlinear optical modes is determined by the interplay of the radiation field with the functional form of the material nonlinearity [3]. In the case of optical beams the nonlinear response can be described in terms of the induced change in the refractive index n which is often approximated as a local function of the wave intensity, i.e. n(r) = n(I(r)). However, in many real physical systems the nonlinear response is spatially nonlocal which means that the refractive index depends on the beam intensity in the neighborhood of each spatial point. This can be phenomenologically expressed as n(r) = dr ′ K(r, r ′ )I(r ′ ), where the response kernel K depends on the particular model of nonlocality [4].It has been shown that nonlocality drastically affects the stationary structure and dynamics of spatial solitons, leading to such effects as collapse arrest of high intensity beams and stabilization of otherwise unstable complex solitonic structures [5,6,7,8]. Nonlocality is often the consequence of transport processes which include atom or heat diffusion in atomic vapors [9], plasma [10] and thermal media [11], or charge drift in photorefractive crystals [12]. In addition long range interactions are responsible for a nonlocal response in liquid crystals [13] or dipolar Bose Einstein condensates [14].Hot atomic vapors are an important and widely used nonlinear medium. The nonlocal nonlinear response of atomic vapors has previously only been associated with state dependent transport of ground state atoms which possess a multilevel structure [9]. In this letter we introduce a new and significant mechanism of nonlocality in atomic vapors which is provided by the ballistic transport of excited atoms and is important even for the simplest case of an idealized two-level atom. We show using parameters representative of beam propagation in Rubidium vapor that ballistic transport plays a dramatic role leading to stabilization of otherwise unstable vortex modes in the presence of a self-focusing nonlinearity.Prior to introducing a model for the nonlocal character of the refractive index we first recall the main features of beam propagation in a hot atomic vapor. We consider a scalar traveling wave E = E(x,y,z) 2 e ı(kz−ωt) + c.c. For all parameters of interest the refractive index is n ≃ 1 so the wave intensity is I ≃ ǫ0c 2 |E| 2 . In the slowly varying envelope approx...

show abstract

Self-Focusing and Waveguide Propagation in a Plasma

Cited by 38 publications

References 6 publications

Modulational instability, solitons and beam propagation in spatially nonlocal nonlinear media

Modulational instability, solitons and beam propagation in spatially nonlocal nonlinear media

Quadratic solitons as nonlocal solitons

Nonlocal Stabilization of Nonlinear Beams in a Self-Focusing Atomic Vapor

Contact Info

Product

Resources

About