Results 81 to 90 of about 149,510 (298)

Towards optimization of pulsed sodium laser guide stars

, 2015
Pulsed sodium laser guide stars (LGS) are useful because they allow for Rayleigh blanking and fratricide avoidance in multiple-LGS systems. Bloch-equation simulations of sodium-light interactions show that these may be able to achieve photon returns ...
Gavel, Donald, Holzlohner, Ronald, Rampy, Rachel, Rochester, Simon M.   +3 more
core   +1 more source

Influence of an Argon/Silane Atmosphere on the Temperature of a Thermal Plasma

Advanced Engineering Materials, EarlyView.
The influence of a silane‐doped argon atmosphere on the chemical composition and temperature of a thermal nontransferring argon plasma is investigated using optical emission spectroscopy. As a result of the high amount of free electrons resulting from the stepwise ionization and dissociation of the silane molecule, even a silane addition of 0.01 vol ...
Lena Kreie, David Kramer, Thomas Scheithauer, Hans Jürgen Maier, Thomas Hassel   +4 more
wiley   +1 more source

Suspended Ring-Core Photonic Crystal Fiber Gas Sensor With High Sensitivity and Fast Response

IEEE Photonics Journal, 2015
We demonstrate the design and fabrication of an in-line evanescent field gas sensor based on a novel suspended ring-core photonic crystal fiber (PCF) to further overcome limitations in sensing capability.
Sahar Hosseinzadeh Kassani, Reza Khazaeinezhad, Yongmin Jung, Jens Kobelke, Kyunghwan Oh   +4 more
doaj   +1 more source

Sub-kHz lasing of a CaF_2 Whispering Gallery Mode Resonator Stabilized Fiber Ring Laser

, 2012
We utilize a high quality calcium fluoride whispering-gallery-mode resonator to stabilize a simple erbium doped fiber ring laser with an emission frequency of 196 THz (wavelenght 1530 nm) to a linewidth below 650 Hz.
Alnis, B. Sprenger, Baaske, Barnes, Baumgartel, Chijioke, Conti, Dale, F. Sedlmeir, Fescenko, Grudinin, H. G. L. Schwefel, Kieu, Kieu, L. J. Wang, Lea, Lee, Li, Li, Liang, M. C. Collodo, Matsko, Numata, Premoli, Rubiola, S. Svitlov, Savchenkov, Sprenger, Sprenger, Vahala, Wang   +30 more
core   +1 more source

A Numerical–Experimental Approach for Multi‐Matrix Fiber‐Reinforced Plastics Characterization Using Finite Element Model Updating

Advanced Engineering Materials, EarlyView.
A numerical–experimental framework is developed for characterizing multi‐matrix fiber‐reinforced polymers (MM‐FRPs) combining epoxy and polyurethane matrices. Harmonic bending tests are integrated with finite element model updating (FEMU) to simultaneously identify elastic and viscoelastic material parameters.
Rodrigo M. Dartora, Tales V. Lisbôa, Axel Spickenheuer, Rogério J. Marczak, Jakson M. Vassoler   +4 more
wiley   +1 more source

A Federated Learning Scheme for Eavesdropper Detection in B5G - IIoT Network Orientations

IEEE Open Journal of the Communications Society
In heterogeneous Beyond 5G (B5G) environments, the adoption of sophisticated Physical Layer (PHY) enhancements, such as Physical Layer Security (PLS) techniques, play a vital role in safeguarding sensitive transmissions against eavesdropping threats ...
Maria Lamprini A. Bartsioka, Ioannis A. Bartsiokas, Panagiotis K. Gkonis, Anastasios K. Papazafeiropoulos, Dimitra-Theodora I. Kaklamani, Iakovos S. Venieris   +5 more
doaj   +1 more source

High-order Radio Frequency Differentiation via Photonic Signal Processing with an Integrated Micro-resonator Kerr Optical Frequency Comb Source

, 2017
We demonstrate the use of integrated micro-resonator based optical frequency comb sources as the basis for transversal filtering functions for microwave and radio frequency photonic filtering and advanced functions.Comment: 8 pages, 7 figures, 46 ...
Chu, Sai T., Little, Brent E., Mitchell, Arnan, Morandotti, Roberto, Moss, David J., Shoeiby, Mehrdad, Wu, Jiayang, Xu, Xingyuan   +7 more
core   +1 more source

Thermomechanical Fatigue and Creep–Fatigue Interaction of Inconel 718 Additively Manufactured by Laser Beam Powder Bed Fusion

Advanced Engineering Materials, EarlyView.
Thermomechanical fatigue tests of laser beam powder bed fusion (PBF‐LB) Inconel 718 show that the additively manufactured material reaches almost the lifetimes of conventionally‐rolled material under no‐dwell conditions. Introducing dwell times at the maximum temperature markedly reduces the lifetimes due to pronounced grain boundary sliding associated
Stefan Guth, Tomáš Babinský, Jan Lars Riedel, Wen Hao Kan, Aijun Huang, Martin Heilmaier, Ivo Šulák   +6 more
wiley   +1 more source

Thermal coefficient of delay for various coaxial and fiber-optic cables [PDF]

Data are presented on the thermal coefficient of delay for various coaxial and fiber optic cables, as measured by the Frequency and Timing Systems Engineering Group and the Time and Frequency Systems Research Group.
Diener, W., Lutes, G. F.
core   +1 more source

Effect of Laser Deoxidation on Adhesive‐Bonded Aluminum in an Oxygen‐Free Atmosphere

Advanced Engineering Materials, EarlyView.
This study investigates laser ablation of aluminum under oxygen‐free conditions. The goal is to produce oxide‐free substrates that enable improved adhesive bonding with epoxy. Optimized laser parameters (90% overlap, 300 µJ) combined with oxide‐free substrates result in the highest tensile strength of the adhesive bond.
Sandra Gerland, Finn‐Lennard Janthur, Sarah Seffer, Jörg Hermsdorf, Ludger Overmeyer, Annika Raatz   +5 more
wiley   +1 more source