scholarly journals Multimode Bus Coupler for Device Communication Integrated in 3D-Opto-MID

2021 ◽  
Vol 18 (2) ◽  
pp. 59-66
Author(s):  
Lukas Lorenz ◽  
Krzysztof Nieweglowski ◽  
Karlheinz Bock

Abstract In this article, we give an overview of the development of an asymmetric optical bus coupler (AOBC) from the theoretical basis, the optical continuous wave, and bit rate performance to the implementation in a 3-D-Opto-MID package. The coupler allows for an interruption-free and bidirectional connection between two multimode waveguides, with different coupling ratios at the same node up to an aspect ratio of 5:1 depending on the coupling direction. For the first time, data transmission up to 12.5 Gbit/s is demonstrated with the AOBC, as well as the full implementation of the coupling element into a 3-D-Opto-MID package including an electrical test circuit.

2003 ◽  
Vol 772 ◽  
Author(s):  
T. Seeger ◽  
G. de la Fuente ◽  
W.K. Maser ◽  
A.M. Benito ◽  
A. Righi ◽  
...  

AbstractCarbon nanotubes (CNT) are interesting candidates for the reinforcement in robust composites and for conducting fillers in polymers due to their fascinating electronic and mechanical properties. For the first time, we report the incorporation of multi walled carbon nanotubes (MWNTs) into silica-glass surfaces by means of partial surface-melting caused by a continuous wave Nd:YAG laser. MWNTs were detected being well incorporated in the silica-surface. The composites are characterized using scanning electron microscopy (SEM) and Raman-spectroscopy. A model for the composite-formation is proposed based on heatabsorption by MWNTs and a partial melting of the silica-surface.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Ankita RayChowdhury ◽  
Ankita Pramanik ◽  
Gopal Chandra Roy

AbstractThis paper presents an approach to access real time data from underground mine. Two advance technologies are presented that can improve the adverse environmental effect of underground mine. Visible light communication (VLC) technology is incorporated to estimate the location of miners inside the mine. The distribution of signal to noise ratio (SNR) for VLC system is also studied. In the second part of the paper, long range (LoRa) technology is introduced for transmitting underground information to above the surface control room. This paper also includes details of the LoRa technology, and presents comparison of ranges with existing above the surface technologies.


Molbank ◽  
10.3390/m1200 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1200
Author(s):  
R. Alan Aitken ◽  
Dheirya K. Sonecha ◽  
Alexandra M. Z. Slawin

The X-ray structure of the title compound has been determined for the first time. Data on its 1H–13C-NMR coupling constants and 15N-NMR spectrum are also given.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Ruchkina ◽  
Dina Hot ◽  
Pengji Ding ◽  
Ali Hosseinnia ◽  
Per-Erik Bengtsson ◽  
...  

AbstractLaser-induced grating spectroscopy (LIGS) is for the first time explored in a configuration based on the crossing of two focused femtosecond (fs) laser pulses (800-nm wavelength) and a focused continuous-wave (cw) laser beam (532-nm wavelength). A thermal grating was formed by multi-photon absorption of the fs-laser pulses by $$\hbox {N}_{{2}}$$ N 2 with a pulse energy around 700 $$\upmu $$ μ J ($$\sim $$ ∼ 45 TW/$$\hbox {cm}^{2}$$ cm 2 ). The feasibility of this LIGS configuration was investigated for thermometry in heated nitrogen gas flows. The temperature was varied from room temperature up to 750 K, producing strong single-shot LIGS signals. A model based on the solution of the linearized hydrodynamic equations was used to extract temperature information from single-shot experimental data, and the results show excellent agreement with the thermocouple measurements. Furthermore, the fluorescence produced by the fs-laser pulses was investigated. This study indicates an 8-photon absorption pathway for $$\hbox {N}_{{2}}$$ N 2 in order to reach the $$\hbox {B}^{3}\Pi _{g}$$ B 3 Π g state from the ground state, and 8 + 5 photon excitation to reach the $$\hbox {B}^{2}\Sigma _{u}^{+}$$ B 2 Σ u + state of the $$\hbox {N}_{2}^{+}$$ N 2 + ion. At pulse energies higher than 1 mJ, the LIGS signal was disturbed due to the generation of plasma. Additionally, measurements in argon gas and air were performed, where the LIGS signal for argon shows lower intensity compared to air and $$\hbox {N}_{{2}}$$ N 2 .


2021 ◽  
Vol 127 (3) ◽  
Author(s):  
Umit Demirbas ◽  
Martin Kellert ◽  
Jelto Thesinga ◽  
Yi Hua ◽  
Simon Reuter ◽  
...  

AbstractWe present detailed experimental results with cryogenic Yb:YLF gain media in rod-geometry. We have comparatively investigated continuous-wave (cw) lasing and regenerative amplification performance under different experimental conditions. In the cw lasing experiments effect of crystal doping, cw laser cavity geometry and pump wavelength on lasing performance were explored. Regenerative amplification behavior was analyzed and the role of depolarization losses on performance was investigated. A recently developed temperature estimation method was also employed for the first time in estimating average crystal temperature under lasing conditions. It is shown that the thermal lens induced by transverse temperature gradients is the main limiting factor and strategies for future improvements are discussed. To the best of our knowledge, the achieved results in this study (375 W in cw, and 90 W in regenerative amplification) are the highest average powers ever obtained from this system via employing the broadband E//a axis.


Author(s):  
Piotr Michoń

AbstractThe need for qualitative research of deservingness perception is strongly emphasised in the literature. This article studies the perception of deservingness for a "Family 500 +"—cash benefit in Poland. For the first time, data from online forums was used in the studies of deservingness and welfare attitudes. It allowed to avoid numerous limitations associated with social surveys. The qualitative analysis showed how participants of Internet debates perceive the criteria of deservingness: control, attitude, reciprocity, identity, need, and what are the relations between the criteria. The impurity of all deservingness criteria was indicated and a new criterion “adequacy” was proposed. Moreover due to the fact that the study concerned a concrete, non-abstract family cash benefit addressed the relationship between the perceived deservingness of children and their parents was pointed out. The vast majority of posts on Internet forums referred to deservingness of parents, not children. This is particularly evident in relation to the criteria of control and reciprocity. Presenting the hypothesis of jealousy and scapegoat strategy, the article also shows the direction of future research on deservingness.


Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1802
Author(s):  
Eduardo Martinez-de-Rioja ◽  
Daniel Martinez-de-Rioja ◽  
Rafael López-Sáez ◽  
Ignacio Linares ◽  
Jose A. Encinar

This paper presents two designs of high-efficiency polarizer reflectarray antennas able to generate a collimated beam in dual-circular polarization using a linearly polarized feed, with application to high-gain antennas for data transmission links from a Cubesat. First, an 18 cm × 18 cm polarizer reflectarray operating in the 17.2–22.7 GHz band has been designed, fabricated, and tested. The measurements of the prototype show an aperture efficiency of 52.7% for right-handed circular polarization (RHCP) and 57.3% for left-handed circular polarization (LHCP), both values higher than those previously reported in related works. Then, a dual-band polarizer reflectarray is presented for the first time, which operates in dual-CP in the frequency bands of 20 GHz and 30 GHz. The proposed antenna technology enables a reduction of the complexity and cost of the feed chain to operate in dual-CP, as a linear-to-circular polarizer is no longer required. This property, combined with the lightweight, flat profile and low fabrication cost of printed reflectarrays, makes the proposed antennas good candidates for Cubesat applications.


2010 ◽  
Vol 31 (3) ◽  
pp. 252-287 ◽  
Author(s):  
Katie Barnfield ◽  
Isabelle Buchstaller

We report on longitudinal changes in the system of intensification in an innovative corpus that spans five decades of dialectal speech. Our analyses allow us — for the first time in a British context — to trace the quantitative development in the variable across four generations. Longitudinal analysis across real and apparent time determines the effect of extralinguistic and intralinguistic variables on intensification in Tyneside and tests to what extent real time data corroborates trends reported from previous apparent time analyses. Long-term competition within the variable manifests itself in distinctive developmental trajectories: expansion — both proportionally within the variable as well as across adjectival categories — tends to follow one of three types of patterns, exemplified, respectively, by really, so and dead. Variant retraction, however, follows only one schema. Importantly, numerical decline in the system does not necessarily go hand in hand with a reduction in breadth of application.


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