scholarly journals Secure high-speed spread spectrum transmission system with orbital angular momentum

2020 ◽  
Vol 14 (11) ◽  
pp. 1709-1717 ◽  
Author(s):  
Chao Zhang ◽  
Xuefeng Jiang
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Spread Spectrum ◽  
High Speed ◽  
Transmission System

scholarly journals Ultrafast control of fractional orbital angular momentum of microlaser emissions

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhifeng Zhang ◽  
Haoqi Zhao ◽  
Danilo Gomes Pires ◽  
Xingdu Qiao ◽  
Zihe Gao ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Optical Communication ◽  
High Speed ◽  
Quantum Information Processing ◽  
Time Window ◽  
Gain Medium ◽  
Control Pulse ◽  
Processing Technologies ◽  
On Chip

Abstract On-chip integrated laser sources of structured light carrying fractional orbital angular momentum (FOAM) are highly desirable for the forefront development of optical communication and quantum information–processing technologies. While integrated vortex beam generators have been previously demonstrated in different optical settings, ultrafast control and sweep of FOAM light with low-power control, suitable for high-speed optical communication and computing, remains challenging. Here we demonstrate fast control of the FOAM from a vortex semiconductor microlaser based on fast transient mixing of integer laser vorticities induced by a control pulse. A continuous FOAM sweep between charge 0 and charge +2 is demonstrated in a 100 ps time window, with the ultimate speed limit being established by the carrier recombination time in the gain medium. Our results provide a new route to generating vortex microlasers carrying FOAM that are switchable at GHz frequencies by an ultrafast control pulse.

High speed acoustic communication with orbital angular momentum multiplexing

2017 ◽  
Vol 142 (4) ◽  
pp. 2682-2682
Author(s):  
Chengzhi Shi ◽  
Marc Dubois ◽  
Yuan Wang ◽  
Xiang Zhang
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Acoustic Communication ◽  
High Speed

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.

All-fiber orbital angular momentum mode generation and transmission system

2017 ◽  
Vol 403 ◽  
pp. 180-184 ◽  
Author(s):  
Xiaobo Heng ◽  
Jiulin Gan ◽  
Zhishen Zhang ◽  
Qi Qian ◽  
Shanhui Xu ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Transmission System ◽  
Momentum Mode ◽  
Mode Generation

scholarly journals Controlling Conical Beam Carrying Orbital Angular Momentum with Transmissive Metasurface

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jun Sun ◽  
Ke Chen ◽  
Kai Qu ◽  
Junming Zhao ◽  
Tian Jiang ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
High Speed ◽  
Design Method ◽  
Cone Angle ◽  
Full Control ◽  
Potential Applications ◽  
Conical Radiation ◽  
Conical Beam ◽  
Good Agreement

Conical beams have potential uses in wireless and satellite-based communication. In this study, we propose a method using a transmissive metasurface to achieve full control of the diverging effect of orbital angular momentum (OAM) modes to form the desired conical beam. A patch antenna functioning as the feed source is combined with the transmissive metasurface to enable the integration of the source and metasurface. For full control of conical radiation, including the cone angle and OAM mode, we introduce both radial and circumferential phase gradients to the proposed metasurface. Experiments are conducted in the microwave region to validate the design method, which shows good agreement with the simulation results. The proposed metasurface provides a means of flexibly generating conical beams with the designed OAM mode to assist potential applications in high-speed wireless communication.

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