Results 41 to 50 of about 20,118 (299)

Prospects and Challenges of Free Space Optical Communications

, 2018
Free space optical (FSO) transmission is a technology which uses a narrow laser beam to transmit the signal from the source to the destination through the free space. Although it has various advantages, a laser beam propagating through the atmosphere is subjected to different kind of disturbances causing the attenuation of the signal and, in some ...
Abir Touati, Farid Touati, Abderrazak Abdaoui, Amith Khandakar, Ammar Bouallegue   +4 more
openaire   +2 more sources

Adaptive symbol-rate free-space-optical communications [PDF]

2013 Australian Communications Theory Workshop (AusCTW), 2013
Free space optical communications through fading atmospheric channels can achieve improved throughput by using adaptive transmission techniques. This paper considers the use of adaptive symbol-rate and transmit-power methods. We use an idealised model of channel coding that assumes zero errors can be achieved above some SNR threshold and adjust the ...
William G. Cowley, Khoa D. Nguyen, Dirk Giggenbach   +2 more
openaire   +1 more source

An optically powered, free space optical communications receiver

2008 IEEE International Symposium on Circuits and Systems (ISCAS), 2008
Two of the key components of sensor motes are a power source and a communications receiver. One approach to creating very small motes is to use free space optical communication and to scavenge power from the optical downlink. In this paper photodiodes are described that were made on a standard CMOS process and generate electrical power from the ...
Liu, J, Faulkner, G, Collins, S, O'Brien, D, Elston, S   +4 more
openaire   +2 more sources

Physical-Layer Security of a Binary Data Sequence Transmitted With Bessel–Gaussian Beams Over an Optical Wiretap Channel

IEEE Photonics Journal, 2018
When an eavesdropper performs an optical beam-splitting attack in a free-space optical communications channel, it is referred to as an optical wiretap channel, which is an extension of Wyner's wiretap channel model.
Tyan-Lin Wang, Ivan B. Djordjevic
doaj   +1 more source

Free space optical communication based on a multi-wavelength optical phased array using Fresnel reflection

Applied Physics Express
We report a coherent laser transmitter for free space optical communications based on multiwavelength coherent beam combining. We performed 5.6 Gbps free-space optical communications using a two-element optical phased array with three wavelengths ...
Eisuke Haraguchi, Hitomi Ono, Takahiro Suzuki, Tomohiro Akiyama, Akihiro Fujie, Yuta Takemoto, Toshiyuki Ando   +6 more
doaj   +1 more source

Prototype Development and Validation of a Beam-Divergence Control System for Free-Space Laser Communications

Frontiers in Physics, 2022
Being able to dynamically control the transmitted-beam divergence can bring important advantages in free-space optical communications. Specifically, this technique can help to optimize the overall communications performance when the optimum laser-beam ...
Alberto Carrasco-Casado, Koichi Shiratama, Dimitar Kolev, Phuc V. Trinh, Tetsuharu Fuse, Shingo Fuse, Koji Kawaguchi, Yusuke Hashimoto, Masamitsu Hyodo, Takashi Sakamoto, Terufusa Kunisada, Morio Toyoshima   +11 more
doaj   +1 more source

Cyclic Olefin Copolymers as Versatile Materials for Advanced Engineering Applications

Advanced Functional Materials, EarlyView.
Cyclic olefin copolymers (COCs) are presented as highly versatile materials combining tunable synthesis, excellent optical properties, and mechanical robustness. Their potential spans microfluidics, bioengineering, and advanced electronics, while emerging self‐healing and sustainable solutions highlight future opportunities.
Giulia Fredi, Norma Mallegni, Andrea Dorigato, Mario Milazzo   +3 more
wiley   +1 more source

Artificial Intelligence‐Assisted Workflow for Transmission Electron Microscopy: From Data Analysis Automation to Materials Knowledge Unveiling

Advanced Materials, EarlyView.
AI‐Assisted Workflow for (Scanning) Transmission Electron Microscopy: From Data Analysis Automation to Materials Knowledge Unveiling. Abstract (Scanning) transmission electron microscopy ((S)TEM) has significantly advanced materials science but faces challenges in correlating precise atomic structure information with the functional properties of ...
Marc Botifoll, Ivan Pinto‐Huguet, Enzo Rotunno, Thomas Galvani, Catalina Coll, Payam Habibzadeh Kavkani, Maria Chiara Spadaro, Yann‐Michel Niquet, Martin Børstad Eriksen, Sara Martí‐Sánchez, Georgios Katsaros, Giordano Scappucci, Peter Krogstrup, Giovanni Isella, Andreu Cabot, Gonzalo Merino, Pablo Ordejón, Stephan Roche, Vincenzo Grillo, Jordi Arbiol   +19 more
wiley   +1 more source

Tracking Efficiency Improvement According to Incident Beam Size in QPD-Based PAT System for Common Path-Based Full-Duplex FSO Terminals

Sensors, 2022
Free space optical (FSO) communication can support various unmanned aerial vehicles’ (UAVs) applications that require large capacity data transmission.
Siwoong Park, Chan Il Yeo, Young Soon Heo, Ji Hyoung Ryu, Hyun Seo Kang, Dong-Seon Lee, Jae-Hyung Jang   +6 more
doaj   +1 more source

Opportunities of Semiconducting Oxide Nanostructures as Advanced Luminescent Materials in Photonics

Advanced Materials, EarlyView.
The review discusses the challenges of wide and ultrawide bandgap semiconducting oxides as a suitable material platform for photonics. They offer great versatility in terms of tuning microstructure, native defects, doping, anisotropy, and micro‐ and nano‐structuring. The review focuses on their light emission, light‐confinement in optical cavities, and
Ana Cremades, Pedro Hidalgo, David Maestre, Ruth Martínez‐Casado, Emilio Nogales, Beatriz Rodríguez, G. Cristian Vásquez, Bianchi Méndez   +7 more
wiley   +1 more source