High-performance, free-space ruled concave grating demultiplexer

1995 ◽  
Vol 31 (25) ◽  
pp. 2200-2201 ◽  
Author(s):  
F.N. Timofeev ◽  
J.E. Midwinter ◽  
M.N. Sokolskii ◽  
P. Bayvel
Keyword(s):  
Free Space ◽  
High Performance ◽  
Concave Grating

High-performance, free-space ruled concave grating demultiplexer

1995 ◽  
Vol 31 (17) ◽  
pp. 1466-1467 ◽  
Author(s):  
F.N. Timofeev ◽  
M.N. Sokolskii ◽  
J.E. Midwinter ◽  
P. Bayvel
Keyword(s):  
Free Space ◽  
High Performance ◽  
Concave Grating

scholarly journals Co-Design of Free-Space Metasurface Optical Neuromorphic Classifiers for High Performance

ACS Photonics ◽  
2021 ◽  
Author(s):  
François Léonard ◽  
Adam S. Backer ◽  
Elliot J. Fuller ◽  
Corinne Teeter ◽  
Craig M. Vineyard
Keyword(s):  
Free Space ◽  
High Performance

Long-Range LiDAR and Free-Space Data Communication With High-Performance Optical Phased Arrays

2019 ◽  
Vol 25 (5) ◽  
pp. 1-8 ◽  
Author(s):  
Christopher Vincent Poulton ◽  
Matthew J. Byrd ◽  
Peter Russo ◽  
Erman Timurdogan ◽  
Murshed Khandaker ◽  
...  
Keyword(s):  
Long Range ◽  
Free Space ◽  
High Performance ◽  
Phased Arrays ◽  
Data Communication ◽  
Optical Phased Arrays ◽  
Space Data

Hybrid Position/Force Control for a RRR 3-DoF Manipulator

2011 ◽  
Vol 48-49 ◽  
pp. 589-592 ◽  
Author(s):  
Shi Xiang Tian ◽  
Sheng Ze Wang
Keyword(s):  
Force Control ◽  
Free Space ◽  
High Performance ◽  
Degree Of Freedom ◽  
End Effector ◽  
Robot Trajectory ◽  
Simulation Results ◽  
Trajectory Following ◽  
Three Degree Of Freedom

In this paper, a novel hybrid position/force controller has been proposed for a three degree of freedom (3-DOF) of robot trajectory following that is required to switch between position and force control. The whole controller consists of two components: a positional controller and a force controller. Depending on whether the end-effector is in free space or in contact with the environments during work, the two subcontrollers run simultaneously to guide the manipulator tracking in free space and constraint environments. After the principle and stability of the controller are briefly analyzed, simulation results verify that the proposed controller attains a high performance.

scholarly journals Acoustic Bessel Vortex Beam by Quasi-Three-Dimensional Reflected Metasurfaces

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1388
Author(s):  
Yin Wang ◽  
Jiao Qian ◽  
Jian-Ping Xia ◽  
Yong Ge ◽  
Shou-Qi Yuan ◽  
...  
Keyword(s):  
Free Space ◽  
High Performance ◽  
Three Dimensional ◽  
Propagation Distance ◽  
Vortex Beam ◽  
Remote Communication ◽  
Long Distance ◽  
Broad Bandwidth ◽  
Vortex Beams ◽  
Distance Propagation

Vortex beams have a typical characteristic of orbital angular momentum, which provides a new degree of freedom for information processing in remote communication and a form of non-contact manipulation for trapping particles. In acoustics, vortex beams are generally observed on the surface of a metamaterial structure or in a waveguide with a hard boundary owing to the characteristic of easy diffusion in free space. The realization of an acoustic vortex beam with a long-distance propagation in free space still remains a challenge. To overcome this, we report a type of acoustic Bessel vortex (ABV) beam created by a quasi-three-dimensional reflected metasurface in free space based on phase modulation. By using the Bessel and vortex phase profiles, we can realize an ABV beam with the high performances of both Bessel and vortex beams, and its effective propagation distance is larger than 9.2λ in free space. Beyond that, we discuss the bandwidth and topological charge of the ABV beam in detail, and the fractional bandwidth can reach about 0.28. The proposed ABV beam has the advantages of a high-performance vortex, long-distance propagation, and broad bandwidth, which provide a new pathway for designing multifunctional vortex devices with promising applications.

scholarly journals Impact of pointing error on SISO/MISO drones swarm-based free space optical system in weak turbulence regime

2021 ◽  
Vol 23 (2) ◽  
pp. 918
Author(s):  
Abdullah Jameel Mahdi ◽  
Wamidh Jalil Mazher ◽  
Osman Nuri Ucan
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
High Performance ◽  
Signal To Noise Ratio ◽  
Weather Conditions ◽  
Free Space Optical ◽  
Single Input Single Output ◽  
Pointing Error ◽  
Single Output ◽  
Link Distance

<p>Applying the drone-based free space optical (FSO) technology is recent in communication systems. The FSO technology hashigh-security features dueto narrow beamwidth, insusceptible to interferences, free license and landline connection is not appropriate. However, these advantages face many obstacles that affect the system's performance, such as random weather conditions and misalignment. The pointing error Hpis one of the critical factors of the channel gain H. The related parameters of the Hp factor: the pointing error angles θr and the path length Z, were manipulated to extract the applicable values at various receiver diameter values. The proposed system has two topologies: single input single output (SISO) and multiple input single output (MISO), flying in weak atmospheric turbulence. The simulation was done using MATLAB software 2020. The average bit error rate (ABER) for the system versus signal-to-noise ratio (SNR) were verified and analyzed. The results showed that at θr=10<sup>−3</sup>rad, Z increased in the range 10~100m for each one-centimeter increase of DR. At θr=10<sup>−2</sup>rad, the applicable Z was nearly 10% of the link distance Z when θr=10<sup>−3</sup>rad was applied. Consequently, an increase in θr must correspond decrease in Z and vice versa to maintain the system at high performance.</p>

Analysis of Atmospheric Turbulence on Free Space Optical System using Homotopy Perturbation Method

2019 ◽  
Vol 40 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Monika Rani ◽  
Harbax Singh Bhatti ◽  
Vikramjeet Singh
Keyword(s):  
Perturbation Method ◽  
Atmospheric Turbulence ◽  
Free Space ◽  
Secure Communication ◽  
High Performance ◽  
Homotopy Perturbation Method ◽  
Communication Link ◽  
Free Space Optical ◽  
Aperture Diameter ◽  
Homotopy Perturbation

AbstractFree Space Optics (FSO) is a wireless optical communication technology which depends on propagation of optical beam through air. FSO communication system provides secure communication link, cost-effective solution and license-free operation. In this paper, the FSO communication link has been analysed in turbulent atmosphere using homotopy perturbation method (HPM). We have designed a FSO system operating at an optical wavelength of 850 nm with a signal power of 4 dBm having a link range of 2 km between transmitter and receiver unit. It has been observed that in atmospheric turbulence high performance FSO link is achieved by increasing the aperture diameter of receiver telescope.

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