On-Chip Detection of Orbital Angular Momentum Beam by Plasmonic Nanogratings

Author(s):

Ji Chen and Xi Chen and Tao Li and Shining Zhu

Abstract:

“Thanks to the unlimited orthogonal states, the orbital angular momentum (OAM) light is widely accepted as a promising carrier for high information multiplexing in optical communications, in which the OAM detection is an important issue. To keep up with the ever‐growing demand for compact integration, here, a plasmonic grating is employed to spatially couple the OAM modes into two separated propagating surface plasmon polariton (SPP) beams with different splitting angles. These splitting angles are found to strongly rely on the topological charges of the incident beams and are insensitive to the specific location of the OAM beam illumination, which provides an intuitive detection of the OAM modes without particular alignment. Besides, a further unidirectional SPP launching from the OAM beam is also achieved by a particular composite grating. With such composite grating, both the topological charge value and sign of OAM beam in a single measurement can be detected. Our results provide a convenient method for alignment‐free OAM detection by a compact device, and would inspire more multiplexing applications in nanophotonics.”

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Publication: Laser & Photonics Reviews

Issue/Year/DOI: Laser & Photonics Reviews Volume 12, Issue 8 (2018)

DOI: 10.1002/lpor.201700331

Obstacle evasion in free-space optical communications utilizing Airy beams

Author(s):

Guoxuan Zhu and Yuanhui Wen and Xiong Wu and Yujie Chen and Jie Liu and Siyuan Yu
Abstract:

“A high speed free-space optical communication system capable of self-bending signal transmission around line-of-sight obstacles is proposed and demonstrated. Airy beams are generated and controlled to achieve different propagating trajectories, and the signal transmission characteristics of these beams around the obstacle are investigated. Our results confirm that, by optimizing their ballistic trajectories, Airy beams are able to bypass obstacles with more signal energy and thus improve the communication performance compared with normal Gaussian beams.”

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Publication: Optics Letters
Issue/Year/DOI: Optics Letters Volume 43, Issue 6, pp. 1203-1206 (2018)
DOI: 10.1364/OL.43.001203

Spin-orbit interaction of light induced by transverse spin angular momentum engineering

Author(s):

Zengkai Shao and Jiangbo Zhu and Yujie Chen and Yanfeng Zhang and Siyuan Yu

Abstract:

“The investigations on optical angular momenta and their interactions have broadened our knowledge of light’s behavior at sub-wavelength scales. Recent studies further unveil the extraordinary characteristics of transverse spin angular momentum in confined light fields and orbital angular momentum in optical vortices. Here we demonstrate a direct interaction between these two intrinsic quantities of light. By engineering the transverse spin in the evanescent wave of a whispering-gallery-mode-based optical vortex emitter, a spin-orbit interaction is observed in generated vortex beams. Inversely, this unconventional spin-orbit interplay further gives rise to an enhanced spin-direction locking effect in which waveguide modes are unidirectionally excited, with the directionality jointly controlled by the spin and orbital angular momenta states of light. The identification of this previously unknown pathway between the polarization and spatial degrees of freedom of light enriches the spin-orbit interaction phenomena, and can enable various functionalities in applications such as communications and quantum information processing.”

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Publication: Nature Communications

Issue/Year/DOI: Nature Communicationsvolume 9, Article number: 926 (2018)
DOI: 10.1038/s41467-018-03237-5

Programmable Vector Mode Multiplexer

Author(s): N. K. Fontaine and H. Chen and R. Ryf and D. Neilson and J. C. Alvarado and J. van Weerdenburg and R. Amezcua-Correa and C. Okonkwo and J. Carpenter

Abstract:

“We demonstrate a programmable vector mode multiplexer using a low-loss spatial light phase modulator that can multiplex 10 modes. It is reconfigured to generate modes for multi-mode fiber and modes with arbitrary polarization including linear, radial, and azimuthal.”

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Publication: 2017 European Conference on Optical Communication (ECOC)

Issue/Year/DOI: 2017 European Conference on Optical Communication (ECOC)
DOI: 10.1109/ECOC.2017.8346099

Free-space optical communication link using perfect vortex beams carrying orbital angular momentum ({OAM})

Author(s):

Fuquan Zhu and Sujuan Huang and Wei Shao and Jie Zhang and Musheng Chen and Weibing Zhang and Junzhang Zeng

Abstract:

“We experimentally demonstrate a free-space optical communication link using perfect vortex beams. Perfect vortex beams with different topological charges are generated using a phase-modulation-type spatial light modulator (SLM) loaded with novel phase holograms based on the Bessel function. With the help of a
microscope objective and simple lens, perfect vortex beams are transmitted effectively for a certain distance. After completing the demodulation of perfect vortex beams carrying OFDM 16-QAM signals and a series of offline processing on the Gaussian bright spot demodulated from the perfect vortex beams, we also achieve a communication link. The constellations and mean bit error rates (BER) of subcarriers are shown.”

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Publication: Optics Communications

Issue/Year/DOI: Optics Communications Volume 396, Pages 50-57
DOI: 10.1016/j.optcom.2017.03.023

Miniature wide-spectrum mode sorter for vortex beams produced by 3D laser printing

Author(s):

Shlomi Lightman and Gilad Hurvitz and Raz Gvishi and Ady Arie

Abstract:

“Optical vortex beams can be used as carriers of information in optical communication and quantum optics applications. Owing to their spatial orthogonality, these beams can be multiplexed and demultiplexed, but up until now this was primarily achieved by bulky and large devices. In this work, a new approach is used to fabricate miniature vortex mode sorters based on three-dimensional laser printing, thereby enabling direct integration into optical systems. Mode sorters that are composed of two separate elements as well as a single integrated device are presented. These devices can handle both pure and mixed vortex beams with topological charge |𝑙|3 and |𝑙|2 for the dual-element device and integrated system, respectively. Mode-sorter spectral bandwidth and surface-quality effects are also discussed.”

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Publication: Optica

Issue/Year/DOI: Optica, Vol 4. , Issue 6, pp. 605- 610 (2018)
DOI: 10.1364/OPTICA.4.000605

Linearly polarized vector modes: enabling MIMO-free mode-division multiplexing

Author(s):

Lixian Wang, Reza Mirzaei Nejad, Alessandro Corsi, Jiachuan Lin, Younès Messaddeq, Leslie Rusch, and Sophie LaRochelle

Abstract:

“We experimentally investigate mode-division multiplexing in an elliptical ring core fiber (ERCF) that supports linearly polarized vector modes (LPV). Characterization show that the ERCF exhibits good polarization maintaining properties over eight LPV modes with effective index difference larger than 1 × 10−4. The ERCF further displays stable mode power and polarization extinction ratio when subjected to external perturbations. Crosstalk between the LPV modes, after propagating through 0.9 km ERCF, is below −14 dB. By using six LPV modes as independent data channels, we achieved the transmission of 32 Gbaud QPSK over 0.9 km ERCF without any multiple-input-multiple-output (MIMO) or polarization-division multiplexing (PDM) signal processing.”

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Publication:Optics Express

Issue/Year/DOI: Optics Express Vol. 25, Issue 10, pp. 11736-11749 (2017)

DOI: 10.1364/OE.25.011736