scholarly journals On-Chip Guiding of Higher-Order Orbital Angular Momentum Modes

Photonics ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 72 ◽  
Author(s):  
In Joon Lee ◽  
Sangin Kim
Keyword(s):  
Angular Momentum ◽  
Field Distribution ◽  
Orbital Angular Momentum ◽  
Rotational Symmetry ◽  
Higher Order ◽  
Waveguide Structure ◽  
Rotation Symmetry ◽  
Gaussian Mode ◽  
On Chip ◽  
Topological Charges

Higher-order orbital angular momentum (OAM) mode guiding in a waveguide which is suitable for on-chip integration has been investigated. Based on the relation between the Laguerre-Gaussian mode and the Hermite-Gaussian mode, it has been shown that two degenerate guided modes of π/2l-rotation symmetry can support the l-th order OAM mode. In order to mimic the rotational symmetry, we have proposed the waveguide structure of a cross-shaped core and designed a waveguide that can support OAM modes of ±1 and ±2 topological charges simultaneously at a wavelength of 1550 nm. Purity of the OAM modes guided in the designed waveguide has been assessed by numerically calculating their topological charges from the field distribution, which were close to the theoretical values. We also investigated the guiding of OAM modes of ±3 and ±4 topological charges in our proposed waveguide structure, which revealed the possibility of the separate guiding of those OAM modes with relatively lower purity.

scholarly journals High-Efficiency Spin-Related Vortex Metalenses

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1485
Author(s):  
Wei Wang ◽  
Ruikang Zhao ◽  
Shilong Chang ◽  
Jing Li ◽  
Yan Shi ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Topological Charge ◽  
High Efficiency ◽  
Infrared Band ◽  
Mid Infrared ◽  
Integrated Devices ◽  
Vortex Beams ◽  
Topological Charges

In this paper, one spin-selected vortex metalens composed of silicon nanobricks is designed and numerically investigated at the mid-infrared band, which can produce vortex beams with different topological charges and achieve different spin lights simultaneously. Another type of spin-independent vortex metalens is also designed, which can focus the vortex beams with the same topological charge at the same position for different spin lights, respectively. Both of the two vortex metalenses can achieve high-efficiency focusing for different spin lights. In addition, the spin-to-orbital angular momentum conversion through the vortex metalens is also discussed in detail. Our work facilitates the establishment of high-efficiency spin-related integrated devices, which is significant for the development of vortex optics and spin optics.

On-chip discrimination of orbital angular momentum of light with plasmonic nanoslits

Nanoscale ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 2227-2233 ◽  
Author(s):  
Shengtao Mei ◽  
Kun Huang ◽  
Hong Liu ◽  
Fei Qin ◽  
Muhammad Q. Mehmood ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Optical Communication ◽  
Communication System ◽  
Degree Of Freedom ◽  
System Capacity ◽  
Optical Communication System ◽  
On Chip

The orbital angular momentum (OAM) of light can be taken as an independent and orthogonal degree of freedom for multiplexing in an optical communication system, potentially improving the system capacity to hundreds of Tbits per second.

scholarly journals Integrated Photonic Orbital Angular Momentum Multiplexing and Demultiplexing on Chip

2014 ◽  
Author(s):  
Ryan P. Scott ◽  
Roberto Proietti ◽  
Binbin Guan ◽  
S. J. Yoo
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
On Chip

Rapid generation of perfect vortex beam without side lobes

2018 ◽  
Vol 32 (24) ◽  
pp. 1850289
Author(s):  
Siqi Li ◽  
Mulong Liu ◽  
Xingyi Li ◽  
Zhiqiang Ge ◽  
Lingxuan Zhang
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Optical Communication ◽  
Spatial Light Modulators ◽  
Vortex Beam ◽  
Digital Micromirror Device ◽  
Light Modulators ◽  
Rapid Generation ◽  
Rapid Switching ◽  
Topological Charges

We have proposed an approach for rapid generation of perfect vortex beam without side lobes through a digital micromirror device (DMD). Employing this method, the amplitude and phase of far field can be controlled indirectly by changing the rotation state of each unit on the DMD. The perfect vortex beams of equal rings diameter independent of their topological charges are generated commendably and the side lobes are avoided. Moreover, we have demonstrated rapid switching among the generated orbital angular momentum modes at the speed of 10 kHz, which is much faster than that of the usual method realized by spatial light modulators (SLMs). The proposed method is very beneficial for the optical communication and trapping or manipulating the small particle based on orbital angular momentum modes.

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.

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