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Curved singular beams for three-dimensional particle manipulation.

Zhao J, Chremmos ID, Song D, Christodoulides DN, Efremidis NK, Chen Z - Sci Rep (2015)

Bottom Line: For decades, singular beams carrying angular momentum have been a topic of considerable interest.Their intriguing applications are ubiquitous in a variety of fields, ranging from optical manipulation to photon entanglement, and from microscopy and coronagraphy to free-space communications, detection of rotating black holes, and even relativistic electrons and strong-field physics.Our findings may open up new avenues for shaped light in various applications.

View Article: PubMed Central - PubMed

Affiliation: 1] The MOE Key Laboratory of Weak-Light Nonlinear Photonics, and TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China [2] CREOL/College of Optics, University of Central Florida, Orlando, Florida 32816 [3] Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 [4] Science and Technology on Solid-State Laser Laboratory, North China Institute of Electronics Optics, Beijing 100015, China.

ABSTRACT
For decades, singular beams carrying angular momentum have been a topic of considerable interest. Their intriguing applications are ubiquitous in a variety of fields, ranging from optical manipulation to photon entanglement, and from microscopy and coronagraphy to free-space communications, detection of rotating black holes, and even relativistic electrons and strong-field physics. In most applications, however, singular beams travel naturally along a straight line, expanding during linear propagation or breaking up in nonlinear media. Here, we design and demonstrate diffraction-resisting singular beams that travel along arbitrary trajectories in space. These curved beams not only maintain an invariant dark "hole" in the center but also preserve their angular momentum, exhibiting combined features of optical vortex, Bessel, and Airy beams. Furthermore, we observe three-dimensional spiraling of microparticles driven by such fine-shaped dynamical beams. Our findings may open up new avenues for shaped light in various applications.

No MeSH data available.


Schematic of a diffraction-resisting singular beam curving in free space.(a) Propagation of the beam along a curved trajectory, where rays emitted from expanding circles on the input plane are skewed but converged along a specified focal curve. (b) Corresponding helical phase structure of the beam along the curve. Due to the self-acceleration, the center of the singular beam shifts laterally during propagation, but its donut shape and vorticity remain intact (see Media 1).
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f1: Schematic of a diffraction-resisting singular beam curving in free space.(a) Propagation of the beam along a curved trajectory, where rays emitted from expanding circles on the input plane are skewed but converged along a specified focal curve. (b) Corresponding helical phase structure of the beam along the curve. Due to the self-acceleration, the center of the singular beam shifts laterally during propagation, but its donut shape and vorticity remain intact (see Media 1).

Mentions: where the transverse coordinates, defined as (x, y) at the observation plane and (ξ, η) at the input plane, and the propagation distance z are all normalized from the real coordinates. The phase function Q(ξ, η), designed to produce an accelerating singular beam with a given transverse width and a topological charge (of order m), is the key in directing all rays in order to create a curved vortex structure along an arbitrary focal trajectory (f(z), g(z), z), as illustrated in Fig. 1a. Any point on this curve represents the center of the singular beam, i.e., the center of the vortex singularity embedded in the main lobe, as constructed from a bundle of skewed conical rays emanating from the same circle on the input plane. The interference of these rays leads to a high-order Bessel-like pattern with a helical phase that propagates along the predesigned path (Fig. 1b). A detailed procedure and algorithm for computing the phase function Q(ξ, η) is presented in the Supplementary Information S2. As we shall demonstrate below, such carefully designed beams exhibit resistance to diffraction while keeping the central main lobe and topological charge remarkably invariant.


Curved singular beams for three-dimensional particle manipulation.

Zhao J, Chremmos ID, Song D, Christodoulides DN, Efremidis NK, Chen Z - Sci Rep (2015)

Schematic of a diffraction-resisting singular beam curving in free space.(a) Propagation of the beam along a curved trajectory, where rays emitted from expanding circles on the input plane are skewed but converged along a specified focal curve. (b) Corresponding helical phase structure of the beam along the curve. Due to the self-acceleration, the center of the singular beam shifts laterally during propagation, but its donut shape and vorticity remain intact (see Media 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4499814&req=5

f1: Schematic of a diffraction-resisting singular beam curving in free space.(a) Propagation of the beam along a curved trajectory, where rays emitted from expanding circles on the input plane are skewed but converged along a specified focal curve. (b) Corresponding helical phase structure of the beam along the curve. Due to the self-acceleration, the center of the singular beam shifts laterally during propagation, but its donut shape and vorticity remain intact (see Media 1).
Mentions: where the transverse coordinates, defined as (x, y) at the observation plane and (ξ, η) at the input plane, and the propagation distance z are all normalized from the real coordinates. The phase function Q(ξ, η), designed to produce an accelerating singular beam with a given transverse width and a topological charge (of order m), is the key in directing all rays in order to create a curved vortex structure along an arbitrary focal trajectory (f(z), g(z), z), as illustrated in Fig. 1a. Any point on this curve represents the center of the singular beam, i.e., the center of the vortex singularity embedded in the main lobe, as constructed from a bundle of skewed conical rays emanating from the same circle on the input plane. The interference of these rays leads to a high-order Bessel-like pattern with a helical phase that propagates along the predesigned path (Fig. 1b). A detailed procedure and algorithm for computing the phase function Q(ξ, η) is presented in the Supplementary Information S2. As we shall demonstrate below, such carefully designed beams exhibit resistance to diffraction while keeping the central main lobe and topological charge remarkably invariant.

Bottom Line: For decades, singular beams carrying angular momentum have been a topic of considerable interest.Their intriguing applications are ubiquitous in a variety of fields, ranging from optical manipulation to photon entanglement, and from microscopy and coronagraphy to free-space communications, detection of rotating black holes, and even relativistic electrons and strong-field physics.Our findings may open up new avenues for shaped light in various applications.

View Article: PubMed Central - PubMed

Affiliation: 1] The MOE Key Laboratory of Weak-Light Nonlinear Photonics, and TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China [2] CREOL/College of Optics, University of Central Florida, Orlando, Florida 32816 [3] Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 [4] Science and Technology on Solid-State Laser Laboratory, North China Institute of Electronics Optics, Beijing 100015, China.

ABSTRACT
For decades, singular beams carrying angular momentum have been a topic of considerable interest. Their intriguing applications are ubiquitous in a variety of fields, ranging from optical manipulation to photon entanglement, and from microscopy and coronagraphy to free-space communications, detection of rotating black holes, and even relativistic electrons and strong-field physics. In most applications, however, singular beams travel naturally along a straight line, expanding during linear propagation or breaking up in nonlinear media. Here, we design and demonstrate diffraction-resisting singular beams that travel along arbitrary trajectories in space. These curved beams not only maintain an invariant dark "hole" in the center but also preserve their angular momentum, exhibiting combined features of optical vortex, Bessel, and Airy beams. Furthermore, we observe three-dimensional spiraling of microparticles driven by such fine-shaped dynamical beams. Our findings may open up new avenues for shaped light in various applications.

No MeSH data available.