Flange Angle Design for Waveguide-Based Orbital Angular Momentum Multiplexing Communication Systems

2018 ◽  
Author(s):  
N. Pelin M. H. Salem ◽  
Edip Niver ◽  
Mohamed A. Salem
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Communication Systems ◽  
Flange Angle

scholarly journals Metasurface Spiral Focusing Generators with Tunable Orbital Angular Momentum Based on Slab Silicon Nitride Waveguide and Vanadium Dioxide (VO2)

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1864
Author(s):  
Li Chen ◽  
Lin Zhao ◽  
Yuan Hao ◽  
Wenyi Liu ◽  
Yi Wu ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Vanadium Dioxide ◽  
Communication Systems ◽  
High Speed ◽  
Focal Length ◽  
Polarized Light ◽  
Optical Systems ◽  
Gaussian Beams ◽  
The Impact

The metasurface spiral focusing (MSF) generator has gained attention in high-speed optical communications due to its spatial orthogonality. However, previous MSF generators only can generate a single orbital angular momentum (OAM) mode for one polarized light. Here, a MSF generator with tunable OAM is proposed and it has the ability to transform linearly polarized light (LPL), circularly polarized light or Gaussian beams into vortex beams which can carry tunable OAM at near-infrared wavelength by controlling the phase transition of vanadium dioxide (VO2). Utilizing this MSF generator, the beams can be focused on several wavelength-sized rings with efficiency as high as 76%, 32% when VO2 are in the insulating phase and in the metallic phase, respectively. Moreover, we reveal the relationship between the reflective focal length and transmissive focal length, and the latter is 2.3 times of the former. We further demonstrate the impact of Gaussian beams with different waist sizes on MSF generators: the increase in waist size produces the enhancement in spiral focusing efficiency and the decrease in size of focal ring. The MSF generator we proposed will be applicable to a variety of integrated compact optical systems, such as optical communication systems and optical trapping systems.

scholarly journals Nonlinear Metasurface for Structured Light with Tunable Orbital Angular Momentum

2019 ◽  
Vol 9 (5) ◽  
pp. 958 ◽  
Author(s):  
Yun Xu ◽  
Jingbo Sun ◽  
Jesse Frantz ◽  
Mikhail Shalaev ◽  
Wiktor Walasik ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Communication Systems ◽  
Near Infrared ◽  
Transmission Efficiency ◽  
Photon Absorption ◽  
New Paradigm ◽  
Infrared Wavelength ◽  
Infrared Spectral ◽  
Two Photon Absorption Coefficient

Orbital angular momentum (OAM) beams may create a new paradigm for the future classical and quantum communication systems. A majority of existing OAM beam converters are bulky, slow, and cannot withstand high powers. Here, we design and experimentally demonstrate an ultra-fast, compact chalcogenide-based all-dielectric metasurface beam converter which has the ability to transform a Hermite–Gaussian (HG) beam into a beam carrying an OAM at near infrared wavelength. Depending on the input beam intensity, the topological charge carried by the output OAM beam can be switched between positive and negative. The device provides high transmission efficiency and is fabricated by a standard electron beam lithography. Arsenic trisulfide (As 2 S 3 ) chalcogenide glass (ChG) offers ultra-fast and large third-order nonlinearity as well as a low two-photon absorption coefficient in the near infrared spectral range.

scholarly journals Orbital Angular Momentum Multiplexed Free-Space Optical Communication Systems Based on Coded Modulation

2018 ◽  
Vol 8 (11) ◽  
pp. 2179 ◽  
Author(s):  
Zhen Qu ◽  
Ivan Djordjevic
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Optical Communication ◽  
Free Space ◽  
Communication Systems ◽  
Huffman Coding ◽  
Free Space Optical Communication ◽  
Free Space Optical ◽  
Optical Communication Systems ◽  
Space Optical Communication

In this paper, we experimentally investigate the turbulence mitigation methods in free-space optical communication systems based on orbital angular momentum (OAM) multiplexing. To study the outdoor atmospheric turbulence environment, we use an indoor turbulence emulator. Adaptive optics, channel coding, Huffman coding combined with low-density parity-check (LDPC) coding, and spatial offset are used for turbulence mitigation; while OAM multiplexing and wavelength-division multiplexing (WDM) are applied to boost channel capacity.

scholarly journals Received Probability of Orbital-Angular-Momentum Modes Carried by Diffraction- and Attenuation- Resistant Beams in Weak Turbulent Oceans

2020 ◽  
Vol 8 (9) ◽  
pp. 701
Author(s):  
Yuan Zheng ◽  
Dongyu Yang ◽  
Shiqing Qin ◽  
Yixin Zhang
Keyword(s):  
Refractive Index ◽  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Optical Communication ◽  
Communication System ◽  
Dissipation Rate ◽  
Communication Systems ◽  
Probability Model ◽  
Complex Refractive Index ◽  
Optical Communication Systems

High performance underwater wireless optical communication systems are the key to the construction of high quality underwater optical communication networks. However, seawater absorption and seawater turbulent diffraction should be the main factors limiting the performance of underwater optical communication systems. For this reason, we established the probability model of the orbital angular momentum (OAM) mode received by the communication system to study the influence of the absorbable turbulent seawater channel on the underwater optical communication system with an anti-diffraction and anti-attenuation random (DARR) beam as the signal carrier. In the study, the DARR beam with a large truncated Gaussian aperture was adopted as the signal carrier, seawater absorption was characterized by the complex refractive index of seawater, and seawater turbulence was described by the power spectrum of the refractive index of seawater. By analyzing the relationship between the received probability of the OAM mode of DARR beams and the dissipation rate of kinetic energy per unit of mass of fluid, the ratio of temperature and salinity, dissipation rate of the mean-squared temperature, and other parameters, we show that one can select longer wavelength, smaller OAM quantum number and smaller received diameter to increase the received probability of OAM signal modes. The disturbance of turbulent seawater to the OAM modes with different quantum numbers carried by the DARR beam is less than the corresponding OAM modes carried by the Laguerre–Gaussian beam. Our paper shows that the DARR beam can mitigate the absorption and disturbance of turbulent seawater.

scholarly journals Ultra-compact broadband polarization diversity orbital angular momentum generator with 3.6 × 3.6 μm2 footprint

2019 ◽  
Vol 5 (5) ◽  
pp. eaau9593 ◽  
Author(s):  
Nan Zhou ◽  
Shuang Zheng ◽  
Xiaoping Cao ◽  
Yifan Zhao ◽  
Shengqian Gao ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Communication Systems ◽  
Fundamental Property ◽  
Plane Waveguide ◽  
Polarization Diversity ◽  
Silicon Waveguide ◽  
The Past ◽  
Polarization Of Light ◽  
Distinct Features

Orbital angular momentum (OAM), one fundamental property of light, has been of great interest over the past decades. An ideal OAM generator, fully compatible with existing physical dimensions (wavelength and polarization) of light, would offer the distinct features of broadband, polarization diversity, and ultra-compact footprint. Here, we propose, design, fabricate, and demonstrate an ultra-compact chip-scale broadband polarization diversity OAM generator on a silicon platform with a 3.6 × 3.6 μm2 footprint. The silicon OAM chip is formed by introducing a subwavelength surface structure (superposed holographic fork gratings) on top of a silicon waveguide, coupling the in-plane waveguide mode to the out-plane free-space OAM mode. We demonstrate in theory and experiment the broadband generation of polarization diversity OAM modes (x-/y-polarized OAM+1/OAM−1) from 1500 to 1630 nm with high purity and efficiency. The demonstrations of an ultra-compact broadband polarization diversity OAM generator may open up new perspectives for OAM-assisted N-dimensional optical multiplexing communications/interconnects and high-dimensional quantum communication systems.

scholarly journals An Inner- and Outer-Fed Dual-Arm Archimedean Spiral Antenna for Generating Multiple Orbital Angular Momentum Modes

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 251 ◽  
Author(s):  
Lulu Wang ◽  
Huiyong Chen ◽  
Kai Guo ◽  
Fei Shen ◽  
Zhongyi Guo
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Topological Charge ◽  
Communication Systems ◽  
Spiral Antenna ◽  
Dual Mode ◽  
Archimedean Spiral ◽  
Conical Cavity ◽  
Measurement Results ◽  
Dual Arm

Orbital angular momentum (OAM) beams have attracted great attention owing to their excellent performances in imaging and communication. In this paper, a dual-arm Archimedean spiral antenna (DASA) is proposed to generate multiple OAM states with positive and negative values by feeding at the inner and outer ends, respectively. The topological charge of radiated vortex waves is reconfigurable by tuning the operating frequency. Dual-mode OAM states are generated at different working frequencies (l = ±1 at 3 GHz, l = ±2 at 4 GHz, and l = ±3 at 4.8 GHz). Both the simulation and measurement results demonstrate that OAM beams can be generated effectively by the DASA. In addition, a conical cavity is used to increase the gain of the proposed DASA for more than 5 dBi in comparison to the traditional cylindrical cavity. Furthermore, the qualities of the generated OAM modes by the proposed DASA have been evaluated at different operating frequencies of 3 GHz, 4 GHz, and 4.8 GHz, respectively. The OAM modes purities of l = −1, −2, −3, 1, 2, and 3 are predominate with the proportion of about 81%, 70%, 74%, 78%, 77%, and 75%, respectively. Our results demonstrate that the proposed DASA has great potentials in OAM multiplexing communication systems.

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