Results 41 to 50 of about 11,035 (264)

Toward Practical Digital Phase Alignment for Coherent Beam Combining in Multi-Aperture Free Space Coherent Optical Receivers

IEEE Access, 2020
In free space optical communication systems, multi-aperture coherent optical receivers based on digital coherent beam combining (D-CBC) technique can provide exceptionally high sensitivity and are more robust to the atmosphere turbulence compared with ...
Chenjie Rao, Sheng Cui, Yicong Tu, Keji Zhou, Deming Liu   +4 more
doaj   +1 more source

Coherent beam combining of optical vortices

Optics Letters
We experimentally demonstrate the power scaling of optical vortices using the coherent beam combining technique, encompassing topological charges ranging from ℓ = 1 to ℓ = 5 realized on the basis of a Yb-doped fiber short-pulsed laser system. The combining efficiency varies from 83.2 to 96.9% depending on the topological charge and beam pattern quality
Hossein Fathi, Mikko Närhi, Rafael Barros, Regina Gumenyuk   +3 more
openaire   +4 more sources

Coherent combining of large-aperture high-energy Nd:glass laser amplifiers

High Power Laser Science and Engineering
We present coherent beam combining of nanosecond pulses with 20-J energy and large beams using a Sagnac interferometer geometry based on Nd:glass rod-type amplifiers.
Pierre Lebegue, Joanna De Sousa, Cyril Rapenau, Doina Badarau, Jordan Andrieu, Patrick Audebert, Frédéric Druon, Dimitrios Papadopoulos   +7 more
doaj   +1 more source

Polarization‐resolved femtosecond Vis/IR spectroscopy tailored for resolving weak signals in biological samples using minimal sample volume

FEBS Open Bio, EarlyView.
Unique biological samples, such as site‐specific mutant proteins, are available only in limited quantities. Here, we present a polarization‐resolved transient infrared spectroscopy setup with referencing to improve signal‐to‐noise tailored towards tracing small signals. We provide an overview of characterizing the excitation conditions for polarization‐
Clark Zahn, Karsten Heyne
wiley   +1 more source

Machine learning phase control of filled-aperture coherent beam combining: principle and numerical demonstration

High Power Laser Science and Engineering
Machine learning has already shown promising potential in tiled-aperture coherent beam combining (CBC) to achieve versatile advanced applications. By sampling the spatially separated laser array before the combiner and detuning the optical path delays ...
Hongbing Zhou, Rumao Tao, Xi Feng, Haoyu Zhang, Min Li, Xiong Xin, Yuyang Peng, Honghuan Lin, Jianjun Wang, Lixin Yan, Feng Jing   +10 more
doaj   +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

Time‐Dependent Oxidation and Scale Evolution of a Wrought Co/Ni‐Based Superalloy

Advanced Engineering Materials, EarlyView.
This study shows how a new wrought Co/Ni‐based superalloy resists oxidation at 800 ∘$^\circ$C. The oxide scale changes from rough, fast‐growing spinel to a dense, protective chromia–alumina layer. Atom probe analysis reveals tiny refractory‐rich bubbles at the interface that mark the transition to long‐term, diffusion‐controlled protection ...
Cameron Crabb, Zachary T. Kloenne, Samuel R. Rogers, Chi Hang Dominik Kwok, Mark C. Hardy, Michele S. Conroy, David Dye   +6 more
wiley   +1 more source

Simultaneous realization of time and carrier-envelope phase synchronization for an ultra-intense few-cycle laser pulse coherent combining system

High Power Laser Science and Engineering
Coherent combining of several low-energy few-cycle beams offers a reliable and feasible approach to producing few-cycle laser pulses with energies exceeding the multi-joule level. However, time synchronization and carrier-envelope phase difference (ΔCEP)
Guoli Zhang, Xiao Liang, Hao Xue, Xinglong Xie, Ping Zhu, Fucai Ding, Meizhi Sun, Linjun Li, Rashid Ul Haq, Ailin Guo, Xiangbing Zhu, Jianqiang Zhu   +11 more
doaj   +1 more source

Karl Popper and the Mechanisms of Hydrogen Embrittlement

Advanced Engineering Materials, EarlyView.
Representation of the beginning of loss of ductility rather than embrittlement. Small concentrations of hydrogen in a diffusible form within iron are well‐established to harm the mechanical integrity of steels. There are theories that attempt to explain the pernicious role of hydrogen.
H. K. D. H. Bhadeshia
wiley   +1 more source

Mismatch analysis of all-fiber coherent beam combiners based on the self-imaging effect

High Power Laser Science and Engineering
All-fiber coherent beam combiners based on the self-imaging effect can achieve a near-perfect single laser beam, which can provide a promising way to overcome the power limitation of a single-fiber laser.
Yuefang Yan, Yu Liu, Haoyu Zhang, Yuwei Li, Chao Guo, Qiang Shu, Wenhui Huang, Feng Jing, Rumao Tao   +8 more
doaj   +1 more source