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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.


Demonstration of a singly-charged singular beam (m = 1) self-accelerating along a parabolic trajectory.(a) Computer generated hologram showing a modulated vortex phase at the input. (b) Numerically simulated side-view propagation of the resulting vortex beam along predesigned parabolic trajectory. (c–f) Snapshots of transverse beam patterns taken at different propagation distances marked in (b), where top panels are from simulation and bottom panels from experiment. The dotted white curve illustrates the bending trajectory relative to the launching direction of the initial beam. The insert in (f) corresponds to the interferogram of the singular beam with an inclined plane wave, showing that the vorticity is preserved along propagation.
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f2: Demonstration of a singly-charged singular beam (m = 1) self-accelerating along a parabolic trajectory.(a) Computer generated hologram showing a modulated vortex phase at the input. (b) Numerically simulated side-view propagation of the resulting vortex beam along predesigned parabolic trajectory. (c–f) Snapshots of transverse beam patterns taken at different propagation distances marked in (b), where top panels are from simulation and bottom panels from experiment. The dotted white curve illustrates the bending trajectory relative to the launching direction of the initial beam. The insert in (f) corresponds to the interferogram of the singular beam with an inclined plane wave, showing that the vorticity is preserved along propagation.

Mentions: As a typical example, we first demonstrate a singly-charged (m = 1) optical beam self-accelerating along a parabolic trajectory designed with the aforementioned approach. The calculated phase information is used to create a computer generated hologram3334, as shown in Fig. 2a, and the corresponding numerical simulation of the side-view beam propagation is shown in Fig. 2b. Clearly, the beam possesses a donut-shaped transverse pattern in the main lobe surrounded by a series of rings, as seen from snapshots taken at different propagation distances (Fig. 2c–f). These results illustrate that the Bessel-like singular beam maintains a constant width in the main lobe while bending during propagation, although the overall donut pattern is slightly deformed (mainly due to the interference with rays generating the focus at smaller z) as the peak intensity circulates along the main ring. The interferogram (inset of Fig. 2f) indicates that the vortex structure of the singular beam is preserved even after more than one meter of propagation along the parabolic trajectory. To experimentally demonstrate such a self-accelerating singular beam, an expanded Gaussian beam (λ = 488 nm) passes through a spatial light modulator (SLM) to read out the hologram encoded with the desired phase structure at input. After reconstruction through a typical 4f system with spatial filtering, the beam is recorded by a CCD camera, mapping out the self-bending trajectory by the transverse snapshots taken at different distances as presented in the bottom panels of Fig. 2. Remarkably, such a bending singular beam travels along the predesigned parabolic path up to 140 cm with a fairly invariant (diffraction-resisting) main lobe and a preserving vortex (OAM) structure. These experimental observations are in good agreement with our theoretical predictions.


Curved singular beams for three-dimensional particle manipulation.

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

Demonstration of a singly-charged singular beam (m = 1) self-accelerating along a parabolic trajectory.(a) Computer generated hologram showing a modulated vortex phase at the input. (b) Numerically simulated side-view propagation of the resulting vortex beam along predesigned parabolic trajectory. (c–f) Snapshots of transverse beam patterns taken at different propagation distances marked in (b), where top panels are from simulation and bottom panels from experiment. The dotted white curve illustrates the bending trajectory relative to the launching direction of the initial beam. The insert in (f) corresponds to the interferogram of the singular beam with an inclined plane wave, showing that the vorticity is preserved along propagation.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: Demonstration of a singly-charged singular beam (m = 1) self-accelerating along a parabolic trajectory.(a) Computer generated hologram showing a modulated vortex phase at the input. (b) Numerically simulated side-view propagation of the resulting vortex beam along predesigned parabolic trajectory. (c–f) Snapshots of transverse beam patterns taken at different propagation distances marked in (b), where top panels are from simulation and bottom panels from experiment. The dotted white curve illustrates the bending trajectory relative to the launching direction of the initial beam. The insert in (f) corresponds to the interferogram of the singular beam with an inclined plane wave, showing that the vorticity is preserved along propagation.
Mentions: As a typical example, we first demonstrate a singly-charged (m = 1) optical beam self-accelerating along a parabolic trajectory designed with the aforementioned approach. The calculated phase information is used to create a computer generated hologram3334, as shown in Fig. 2a, and the corresponding numerical simulation of the side-view beam propagation is shown in Fig. 2b. Clearly, the beam possesses a donut-shaped transverse pattern in the main lobe surrounded by a series of rings, as seen from snapshots taken at different propagation distances (Fig. 2c–f). These results illustrate that the Bessel-like singular beam maintains a constant width in the main lobe while bending during propagation, although the overall donut pattern is slightly deformed (mainly due to the interference with rays generating the focus at smaller z) as the peak intensity circulates along the main ring. The interferogram (inset of Fig. 2f) indicates that the vortex structure of the singular beam is preserved even after more than one meter of propagation along the parabolic trajectory. To experimentally demonstrate such a self-accelerating singular beam, an expanded Gaussian beam (λ = 488 nm) passes through a spatial light modulator (SLM) to read out the hologram encoded with the desired phase structure at input. After reconstruction through a typical 4f system with spatial filtering, the beam is recorded by a CCD camera, mapping out the self-bending trajectory by the transverse snapshots taken at different distances as presented in the bottom panels of Fig. 2. Remarkably, such a bending singular beam travels along the predesigned parabolic path up to 140 cm with a fairly invariant (diffraction-resisting) main lobe and a preserving vortex (OAM) structure. These experimental observations are in good agreement with our theoretical predictions.

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.