Architecting new diffraction-resistant light structures and their possible applications in atom guidance

Abstract

In this work we extend the so called frozen wave method in order to obtain new diffraction resistant light structures that can be shaped on demand, with possible applications in atom guidance. The resulting beams and the corresponding optical dipole potentials exhibit a strong resistance to diffraction effects and their longitudinal and transverse intensity patterns can be chosen a priori. Besides the theoretical development, we also present the experimental confirmation of our approach; specifically, by generating three different beam profiles using a spatial light modulator that is addressed by a computer-generated hologram. In addition to its many potential applications in atom guiding, the method developed here can also lead to many new developments in optics and photonics in general.

Evolution of orbital angular momentum in three-dimensional structured light

“…In very special cases, however, non-trivial topological deformations have been deliberately realized; originally, by interfering vortex modes with Gaussian beams [18], then by realizing charge flipping induced in a non-linear medium [19,20], and in noncanoncial vortices generated by an astigmatic optical setup [21,22]. More recently, non-diffracting optical vortices with longitudinally varying topological charge have been observed in air [23][24][25][26][27], thus opening new opportunities in venues like optical trapping [28][29][30], dense data communications [31], and remote sensing [32,33]. In all these developments, a fundamental question on how OAM conservation is seemingly broken, without violating any laws of physics, naturally arises.…”

Structured Light by Linking Diffraction-Resistant Spatially Shaped Beams

“…for biological manipulations, optical guiding of atoms, light orbital angular momentum control, holography, lithography, non-linear-optics, interaction of electromagnetic radiation with Bose-Einstein condensates, and so on, besides in general the field of Localized Waves (non-diffracting beams and pulses). [MZR] ( * ) Visiting c/o Decom, Unicamp, by a PVE fellowship of CAPES (Brazil) arXiv:1712.01118v2 [physics.optics] 5 Apr 2018Structured Light [1,2,3, 4,5,6] has been more and more studied, and applied in various sectors, like optical tweezers [7,8,9,10,11,12,13,14,15,16,17], optical guiding of atoms [18,19,20,21,22,23,24], imaging [25], light orbital angular momentum control and applications [26,27,28,29,30,31], and photonics in general.A rather efficient method to model longitudinally the intensity of non-diffracting beams is by the so-called Frozen Waves (FWs) [1,2,3,32,33,34,35,36], obtained from superpositions of co-propagating Bessel beams, endowed with the same frequency and order. The resulting diffraction resistant beam, with a longitudinal intensity shape freely chosen a priori, may then propagate, remaining confined, along the propagation axis z, or over a cylindrical surface (depending on the order of the constituting Bessel beams), while its "spot" size, and the cy...…”

“…The resulting diffraction resistant beam, with a longitudinal intensity shape freely chosen a priori, may then propagate, remaining confined, along the propagation axis z, or over a cylindrical surface (depending on the order of the constituting Bessel beams), while its "spot" size, and the cylindrical surface radius, can be as well chosen a priori. In this way, it is possible to construct, e.g., cylindrical beams whose static envelopes possess non-negligible energy density in finite, well-defined spatial intervals only: so that they can be regarded as segments or cylindrical pieces of light.Aiming also at a greater control on the beam transverse shape, another method was recently proposed [24,26], where different-order FW-type beams are superposed, which possess appreciable intensities along different, but consecutive, space intervals: So that one ends with cylindrical structures of light endowed with different radii and located in different positions along the z axis. This new method resulted efficient, incidentally, also for controlling the orbital angular momentum along the propagation axis [26].Anyway, and interestingly enough, it is possible to join together in the same way even two FW-type beams bearing the same order, by getting again a structure with two different-radius cylinders, each one in its own space interval.…”

“…Structured Light [1,2,3, 4,5,6] has been more and more studied, and applied in various sectors, like optical tweezers [7,8,9,10,11,12,13,14,15,16,17], optical guiding of atoms [18,19,20,21,22,23,24], imaging [25], light orbital angular momentum control and applications [26,27,28,29,30,31], and photonics in general.…”

“…Aiming also at a greater control on the beam transverse shape, another method was recently proposed [24,26], where different-order FW-type beams are superposed, which possess appreciable intensities along different, but consecutive, space intervals: So that one ends with cylindrical structures of light endowed with different radii and located in different positions along the z axis. This new method resulted efficient, incidentally, also for controlling the orbital angular momentum along the propagation axis [26].…”