Bottle Beams in Nonlocally Defocusing Nonlinear Media

Abstract

The dynamics of the inward-focusing ring Airy beam in nonlocally defocusing nonlinear media is investigated in detail, and a bottle beam shape can be observed by adjusting the amplitude of the inward-focusing ring Airy beam and the nonlocality of the media. The gradient force of the bottle beam is numerically studied. It is worth mentioning that the bottle beams are formed in the nonlinear regime, which indicates that much higher intensity is allowable for these beams than those in the linear regime. Our approach and results may pave the way to the optical tweezers in the nonlinear regime.

Interacting ring-Airy beams in nonlinear media

“…Ring-Airy beams are radially-symmetric field configurations built from the Airy function, first advanced [7] in 2010, and seen experimentally [8] the following year, and can be expressed as [2,3,7]…”

“…It has recently been shown [2,3] that a ring-Airy input will exhibit interesting dynamics in a medium described by the 2+1 NLS equation, including a "double focus" as well as a low-intensity axial region, the position of the latter being controllable by altering the degree of nonlocality of the medium; these features have been argued [2,3] to be potentially useful for particle trapping in nonlinear media, i.e. for optical tweezing in the nonlinear regime.…”

“…When r 0 increases to a threshold value of r 0 ∼3, the low-intensity region starts to bifurcate for the parameter choice a = 0.1. By increasing its value to a = 0.2, whilst keeping the field amplitude the same (A = 3), splitting of the low-intensity regions can be Controllable nodal regions have recently been numerically predicted for a single RAB input in nonlocal nonlinear media [2,3]; in contrast, the results presented in this Letter do not require any nonlocality of the medium (and hence no fine-tuning of the nonlocality): the control emerges simply from changing the initial parameters of the beam. It should be noted that local control of nodal positions is also seen in our numerical results for the evolution of a single RAB, again via the tuning of r 0 values: for a single beam, a node is present only when its initial amplitude exceeds A∼10 (a similar result was shown in Fig.…”

“…Since the first experimental observation of finite-energy Airy optical beams was reported [1] in 2007, there has been a wealth of research on these non-diffracting, freely-accelerating beams in both the linear and nonlinear regimes [2][3][4][5][6][7][8][9][10]. Originally studied in the context of quantum mechanics [11,12], Airy wave packets have entered the field of optics due to the equivalent mathematical descriptions of quantum particles (the Schrödinger equation) and optical waves via the paraxial equation.…”

“…It is known [2][3][4] that a single RAB self-focuses in a Kerr medium and that it can form a local region of zero (or very low) intensity during propagation, potentially useful for particle trapping. Previously [2], the axial location of this region of low intensity -which we shall call a "node" from hereon -has only been shown to be controllable via a tuning of the nonlocality of the Kerr medium in which the beam propagates.…”