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Tytuł:
Raman Polarization Pulling and Amplification for Polarization Division Multiplexing Transmission System
Autorzy:
Perlicki, K.
Powiązania:
https://bibliotekanauki.pl/articles/963829.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fiber optics transmission
light polarization
polarization division multiplexing
Raman scattering
polarization pulling
Opis:
The numerical modelling of the Raman polarization attraction and amplification process in the telecommunication band around 1550 nm is presented. The possibility of achieving both polarization pulling and amplification in Polarization Division Multiplexing transmission system by exploiting the polarization dependence of stimulated Raman scattering is investigated. The acceptable crosstalk for the Polarization Division Multiplexing transmission systems was achieved for some attraction/amplification block parameters.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 4; 519-522
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and Development of Biodegradable 3D Printed RDRA for Polarization Reconfigurability
Autorzy:
Apparao, Maganti
Karunakaran, Godi
Powiązania:
https://bibliotekanauki.pl/articles/2200726.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
polarization switching
circular polarization
linear polarization
dielectric resonator antennas
Opis:
In this article, a 3D printed rectangular dielectric resonator antenna which is capable of polarization reconfiguration has been designed. Dielectric resonator is composed of environment friendly and biodegradable material, which is Polylactic Acid. In the proposed model, the polarization can be switch from a linear to a circular by changing the state of a switch, electonically. The antenna switch between two different polarizations: Linear polarization during OFF STATE and Lefthand circular polarization during ON STATE. The proposed 3D printed dielectric resonator antenna is designed to operate in Cband of microwave spectrum, with a broad effective bandwidth (overlapped impedance bandwidths of both states) of 14.542% with centre frequency at 5.845GHz and peak gain 5.5dBi. Further, validated simulated results with experiment and both results are in good agreement.
Źródło:
International Journal of Electronics and Telecommunications; 2023, 69, 1; 69--74
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fox News and the polarization of attitudes in the U.S.
Autorzy:
Wanta, Wayne
Powiązania:
https://bibliotekanauki.pl/articles/471021.pdf
Data publikacji:
2008-09
Wydawca:
Polskie Towarzystwo Komunikacji Społecznej
Tematy:
polarization
political attitudes
Fox News
Opis:
Mass media in the United States have historically evolved through three stages in which the content is aimed at the elites, then the masses, then specialized audiences. This evolution has recently been taking place within the news media, where Fox News is now being aimed at conservative viewers. The effect of the conservative content of Fox News on its viewership was examined. Findings from a survey show that Fox viewers are more polarized than other news consumers on several issues. Whether they watched Fox News or some other news program, however, the respondents consist- ently felt that the media were between good and fair in their coverage. Fox News viewers seem to be relatively satisfi ed with the news content they receive – or at least as satisfied as respondents who get their information from other sources.
Źródło:
Central European Journal of Communication; 2008, 1, 1; 111-121
1899-5101
Pojawia się w:
Central European Journal of Communication
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
POLARYZACJA GRUPOWA W WARUNKACH DEBATY DELIBERATYWNEJ
Group polarization in deliberative debates
Autorzy:
WESOŁOWSKA, ELŻBIETA
Powiązania:
https://bibliotekanauki.pl/articles/546574.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
group polarization
deliberative debates
citizen deliberation
group discussion
Opis:
In social psychology the group polarization refers to the tendency for groups to make decisions that are more extreme than the initial inclinations of its members. This phenomenon constitutes a potential obstacle to positive outcomes attributed to deliberative debates. A deliberative debate is a particular kind of a group discussion tasked with fi nding group consensus on controversial issues. The idea of deliberation originates from the writings of John Rawls, Jürgen Habermas, Amy Gutmann and Denis Thompson. Deliberative debate imposes numerous normative requirements on the communication, relationships among the disputants and their approach to the issue under discussion. These normative requirements make a big difference between deliberative debates and the situations in which the phenomenon of polarization was observed. Thus, we presume that in deliberative debates conditions the phenomenon of group polarization may be limited. The paper investigates the following questions: would the normative conditions of deliberation limit the occurrence of polarization in discussing groups? and What infl uence (if any) would the polarization process have on the quality of group decision? In the light of the empirical data we concluded what follows: (1) In 50% of the analyzed cases of group discussion the phenomenon of group polarization was observed despite the normative conditions of deliberation. (2) The occurrence of group polarization in some cases coincided with making the fi nal decisions which did not alter the initial preferences of the disputants (but did not totally predestinated the fi nal outcome).
Źródło:
Civitas et Lex; 2014, 2; 19-30
2392-0300
Pojawia się w:
Civitas et Lex
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of telecommunication optical routes to power fiber-optic polarization sensors
Autorzy:
Vyležich, Zdeněk
Kyselák, Martin
Powiązania:
https://bibliotekanauki.pl/articles/2172859.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
power supply
optical route
polarization
temperature sensor
Opis:
A single-mode telecommunication optical route can be used for reliable power supplies of a remote non-electric temperature fiber-optic polarization sensor, but the optical route, due to many physical factors, affects an immediate state of polarization during the transmission. This negative phenomenon changes the sensitivity of the sensor itself. The thesis proposes two main approaches to solving that problem. The first approach is based on the suitable connection of a depolarizer and linear polarizers. The second approach is based on signal interference, which takes place in a polarization-maintaining fiber coupler. This article also evaluates the advantages and disadvantages of the two approaches and graphically demonstrates the functionality of the fiber-optic sensor, which was tested by applying a container with water of different temperatures. A big advantage of this type of sensor is that it is not necessary to have components, that are dependent on electricity, near the monitored place, where there may be no access to electricity, or the place may be sensitive to an electric charge. Paper demonstrates the possibility of successfully powering the non-electric sensor via a classical optical route.
Źródło:
Optica Applicata; 2022, 52, 4; 565--574
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of a Dual-Polarization Dual-Wideband Planar Antenna
Autorzy:
A'isya Nur Aulia Yusuf
Fitri Yuli Zulkifli
Powiązania:
https://bibliotekanauki.pl/articles/2055241.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
planar antenna
dual wideband
dual polarization
Opis:
Wireless communication is a fundamental requirement because of its low cost, high flexibility and convenience, continuing improvements in speed and connectivity, and accessibility in remote areas. One example is very small aperture terminal (VSAT) communication. A VSAT is a two-way satellite ground station operating at C-band and Ku-band frequencies, with linear and circular polarization in the C band and linear polarization in the Ku band. For the data transmitted by a satellite to be utilized by a user, the antenna on the user side must have dual-wideband and dual-polarization characteristics. In this study, a dual-polarization planar dual-wideband antenna with dimensions of 30 x 39 x 1.52 mm3 was designed using a dual-port approach. The introduction of a slot and perturbation on the patch side results in the dual-wideband characteristics of the antenna. The introduction of slots into the antenna ground results in circular polarization. The proposed antenna has resonant frequencies of 3 - 15 GHz on port 1 and 3.31 – 7.79 GHz and 9.05 – 15 GHz on port 2, with circular polarization characteristics on port 1 and linear polarization characteristics on port 2. On port 1, the gains at frequencies of 4.2 GHz is 3.93 dB, while on port 2, the gains at frequencies of 3.9 GHz is 0.51 dB.
Źródło:
International Journal of Electronics and Telecommunications; 2022, 68, 1; 41--46
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Measuring Income Polarization: An Approach Based on Regression Trees
Autorzy:
Mussini, Mauro
Powiązania:
https://bibliotekanauki.pl/articles/466069.pdf
Data publikacji:
2016
Wydawca:
Główny Urząd Statystyczny
Tematy:
polarization
regression trees
recursive partitioning
ANOVA
JEL D31
D63
C14
Opis:
This article proposes the application of regression trees for analysing income polarization. Using an approach to polarization based on the analysis of variance, we show that regression trees can uncover groups of homogeneous income receivers in a data-driven way. The regression tree can deal with nonlinear relationships between income and the characteristics of income receivers, and it can detect which characteristics and their interactions actually play a role in explaining income polarization. For these features, the regression tree is a flexible statistical tool to explore whether income receivers concentrate around local poles. An application to Italian individual income data shows an interesting partition of income receivers.
Źródło:
Statistics in Transition new series; 2016, 17, 2; 221-236
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization in the Turkish Press: Framing the Social Movement in Iran
Autorzy:
Karabiyik, Ali Çağlar
Powiązania:
https://bibliotekanauki.pl/articles/2176106.pdf
Data publikacji:
2023-02-24
Wydawca:
Polskie Towarzystwo Komunikacji Społecznej
Tematy:
News framing
news discourse
polarization
social movement in Iran
Turkish press
Opis:
This study examines the framing of the social movement in Iran launched on 29 December 2017, by analyzing the news texts of six national Turkish newspapers. It discusses the movement in the context of news framing, focusing on problem definition, causal interpretation, moral evaluation, and treatment recommendation. The findings suggest that each newspaper has reported the social movement in Iran quite differently. The most obvious difference is that the left-wing, anti-government press mainly explained the events in terms of political, economic, and social factors while the right-wing, pro-government press attributed the events to ‘foreign forces’ and reflected the dominant discourse of political power while framing the news. Thus, the way Turkish newspapers frame a social movement outside the country reveals the intense polarization in the Turkish press.
Źródło:
Central European Journal of Communication; 2022, 15, 3(32); 341-358
1899-5101
Pojawia się w:
Central European Journal of Communication
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical inference on changes in income polarization in Poland
Wnioskowanie statystyczne o zmianach polaryzacji dochodowej w Polsce
Autorzy:
Brzeziński, Michał
Powiązania:
https://bibliotekanauki.pl/articles/1830746.pdf
Data publikacji:
2011-06-30
Wydawca:
Główny Urząd Statystyczny
Tematy:
polarization
income distribution
statistical inference
Polska
Opis:
This paper estimates a popular measure of economic polarization (DER index) using Polish income micro-data from the Household Budget Survey (HBS) study for the period from 1998 to 2007. Using asymptotically distribution-free statistical inference we test whether the changes in the values of the estimated indices are statistically significant. Results show that during the period under study DER index has increased in the range from 4.9 to 6.5%, depending on the polarization-sensitivity parameter α. For the period 1998-2007, the changes in the DER index with α = 1, for which polarization is empirically distinguishable from inequality, are statistically significant at conventional levels. It is found, however, that for some sub-periods changes in the DER index are not statistically significant.
W artykule dokonano estymacji popularnej miary polaryzacji ekonomicznej (indeks DER) dla danych o dochodach z polskich Badań Budżetów Gospodarstw Domowych w okresie 1998-2007. Używając niezależnych od rozkładu metod wnioskowania statystycznego przeprowadzono testy istotności różnic w wartościach estymowanych wskaźników. Wyniki pokazują, że w badanym okresie wartość indeksu DER wzrosła pomiędzy 4,9 a 6,5% w zależności od wartości parametru α mierzącego wagę przykładaną do polaryzacji. Zmiany indeksu DER dla α = 1, dla którego polaryzacja zachowuje się empirycznie w sposób odmienny od nierówności, są w badanym okresie statystycznie istotne. W artykule pokazano jednak, że niektóre ze zmian indeksu DER dla krótszych okresów nie są istotne statystycznie.
Źródło:
Przegląd Statystyczny; 2011, 58, 1-2; 102-113
0033-2372
Pojawia się w:
Przegląd Statystyczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SO(3) matrix transformation for rapid polarization search and coding in a three-plate polarizer
Autorzy:
Huang, C
Wang, X
Powiązania:
https://bibliotekanauki.pl/articles/174349.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
SO(3) transformer
tabu search
polarization coding
Opis:
A SO(3) transformer of a three-plate polarizer is adopted to rapidly achieve the transformation of the polarized state. The polarization coding based on Stokes components S2 and S3 is analyzed and demonstrated. Tabu search algorithm is used to accelerate the transformation of the polarized state by utilizing Mueller matrix roots decomposition to decompose the SO(3) matrix, and substituting first order Taylor series approximations for the trigonometric functions in the SO(3) matrix. The results show that bias voltage is less than 120 V in the coding zone. The search speed of our algorithm is faster than the one without first order Taylor series approximations by 4 times.
Źródło:
Optica Applicata; 2015, 45, 1; 101-112
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ zasięgu polaryzacji pręta zbrojeniowego na wyniki elektrochemicznych badań korozyjnych
Influence of the rebar polarization range on the results of electrochemical corrosion tests
Autorzy:
Jaśniok, M.
Pamuła, M.
Powiązania:
https://bibliotekanauki.pl/articles/162837.pdf
Data publikacji:
2016
Wydawca:
Polski Związek Inżynierów i Techników Budownictwa
Tematy:
pręt zbrojeniowy
polaryzacja
badanie impedancyjne
korozja elektrochemiczna
zasięg polaryzacji
rebar
polarization
impedance exmination
electrochemical corrosion
polarization range
Opis:
Podjęto próbę eksperymentalnej oceny wpływu na wyniki badań impedancyjnych polaryzacji różnych fragmentów pobocznicy walcowego pręta zbrojeniowego. Pomiary metodą EIS przeprowadzono w układzie trójelektrodowym w roztworze wodnym modelującym ciecz porową betonu. Elektrodą badaną był gładki pręt zbrojeniowy ze stali RB500, przeciwelektrodą prostokątna blacha ze stali odpornej na korozję, a elektrodą referencyjną Cl–/AgCl,Ag. W badaniach zasięg polaryzacji różnicowano po obwodzie pręta, a jako drugą zmienną wprowadzono odległość przeciwelektrody od elektrody badanej. Analiza badań zasadniczo nie wykazała istotnego wpływu na wyniki opisanego sposobu polaryzacji.
An attempt of experimental evaluation of the impact on the impedance test results on polarization of different parts of the circumferential cylindrical rebar was made. EIS measurements have been conducted using three-electrode system in an aqueous solution which models the concrete pore liquid. Working electrode was a smooth rebar made of steel RB 500 grade. The counter electrode was a rectangular sheet made of corrosion-resistant steel, and the reference electrode was Cl–/AgCl,Ag. In the test the polarisation range was differentiated along the circumference of the rod, and as a second variable was introduced the distance between the counter electrode and working electrode. The analysis of the tests generally showed no significant effect on the results of described polarization method.
Źródło:
Przegląd Budowlany; 2016, R. 87, nr 5, 5; 28-31
0033-2038
Pojawia się w:
Przegląd Budowlany
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of polarization molecules reagents of the burning reaction on the efficiency of equipment for thermogeneration
Autorzy:
Kovalyshyn, B.
Powiązania:
https://bibliotekanauki.pl/articles/411199.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
energy efficiency
burning
electric field
high voltage
activation
polarization
Opis:
The aspects of physical and chemical nature of oxidizing-reduction processes of burning were investigated. The communication of efficiency of fuel equipments with polarizing and activating of molecules-reagents was exposed. Application of molecules electro-activation for optimization of the chemical reactions at burning passed at incineration of gaseous hydrocarbon fuels in the oxidizing air environment was grounded experimentally.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2013, 2, 2; 31-35
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization in Optical Fibers
Autorzy:
Woliński, T. R.
Powiązania:
https://bibliotekanauki.pl/articles/2008216.pdf
Data publikacji:
1999-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.81.-i
Opis:
Physical origin of polarization phenomena in highly birefringent optical fibers including nonlinear optical effects is discussed and their impact on applications to polarimetric optical fibers sensors is underlined.
Źródło:
Acta Physica Polonica A; 1999, 95, 5; 749-760
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in the polarization states of random electromagnetic vortex beams propagating in biological tissues
Autorzy:
Duan, M.
Wu, Y.
Su, N.
Powiązania:
https://bibliotekanauki.pl/articles/174047.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
random electromagnetic vortex beam
biological tissue
state of polarization
Opis:
The changes in the on-axis polarization state of random electromagnetic Gaussian Schell-model vortex beams propagating in biological tissues have been studied. In different media propagation, the bigger Cn2 is, the earlier the appearance of the inflexion points in the on-axis degree of the polarization P(0, 0, z) is. As the propagation distance increases, the values of the on-axis orientation angle θ(0, 0, z) undergo several processes: at the beginning they are positive, then gradually increase to the maximum, jump to a negative value, finally tend to a fixed value. The bigger Cn2 corresponds to previous jumping position. In the entire propagation, the values of the on-axis ellipticity ε(0, 0, z) are larger than the initial one. There exists a phenomenon that the values of P(0, 0, z), θ(0, 0, z) and ε(0, 0, z) keep their extremes in a length of propagation distances for the far infrared beams. The maximum of P(0, 0, z) is the smallest and the jumping range of θ(0, 0, z) is the largest for the ultraviolet beams. Compared with σyy > σxx, the changes in magnitudes in P(0, 0, z) are more obvious when σyy < σxx, the changes in θ(0, 0, z) are just the reverse for σyy < σxx.
Źródło:
Optica Applicata; 2018, 48, 2; 297-309
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model of degree of scattering polarization for oil spilling
Autorzy:
Wang, Xiao
Xu, Jiang
Qian, Weixian
Ouyang, Jingyi
Powiązania:
https://bibliotekanauki.pl/articles/1835805.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical mechanism
surface microstructure
degree of scattering polarization
Fresnel formula
oil slick
Opis:
Oil slicks often show uncertain surface roughness and Fresnel reflection parameters. Consequently, differentiating oil spilled on the seawater in these areas using optical sensors is a challenge. Therefore, the optical mechanism of the oil film has been studied by the Maxwell equation. It is found that the polarization characteristics of the oil slicks can help us to overcome this problem. According to the Fresnel formula, the scattering coefficient and scattering rate of the homogeneous oil film have been deduced, and the phase difference of the scattering electromagnetic wave has also been calculated to verify the accuracy of the model. The parameter, a degree of scattering polarization, has been derived to identify the oil slicks on the sea wave. It depends on accurately knowing the Stokes parameter for the reflected light, and varies with the refractive index of the surface layer and viewing angles. The actual spilled oil has been measured by this model, and the oil film can be accurately identified at various angles. These preliminary results suggest that the potential of multi-angle polarization measurement of ocean surface needs further researches.
Źródło:
Optica Applicata; 2020, 50, 3; 433-445
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization dependence of patterning effects in quantum well semiconductor optical amplifier-based wavelength conversion
Autorzy:
Qin, C
Shen, W
Zhao, J.
Yu, H.
Xu, E
Powiązania:
https://bibliotekanauki.pl/articles/173469.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
semiconductor optical amplifiers
polarization
patterning effect
Opis:
In this paper, polarization dependence of patterning effects in quantum well semiconductor optical amplifier-based wavelength conversion is experimentally and theoretically investigated. The carrier and photon density rate equations are numerically solved by using the time-domain traveling wave model. The material gain calculation, including the strain effect in the active layer, is based on the k·p method. By comparing experimental and computational results, it is demonstrated that the polarization of the injection signal has a significant influence on the gain recovery time of quantum well semiconductor optical amplifier. Under the cross-polarized signals injection, the output signals suffer the weakest and strongest patterning effects both for unstrained and tensile strained quantum well semiconductor optical amplifiers.
Źródło:
Optica Applicata; 2015, 45, 2; 163-172
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel method of elimination of light polarization cross sensitivity on tilted fiber Bragg grating bending sensor
Autorzy:
Harasim, Damian
Cięszczyk, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/2173905.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
tilted Bragg grating
optical fiber sensor
polarization
bending measurement
Opis:
The article shows the possibility of using TFBG gratings to measure the radius of curvature of fiber bending in conditions of variable polarization of the introduced light. Most of the modern, stable light sources generate light with a high degree of polarization. Due to the spatial asymmetry, the direction of the light polarization plane affects the spectral parameters of individual modes. For this reason, in the measurement systems using TFBGs presented so far it becomes necessary to determine and control the state of light polarization directly in front of the periodic structure. The article presents the determined spectral parameters of the cladding modes which allow bending measurements regardless of the direction of polarization of the introduced light. Thanks to this, the measuring system can be constructed without providing control of the introduced light polarization angle, which makes its construction simpler. When using TFBGs with an angle of 2°, the accuracy of determining the bending radius in the range from 15 mm to 30 mm when changing the angle of the plane of polarization in the full range is 0.318 mm in the case of changes in the transmission coefficient. For changes in the wavelength of the selected cladding mode, the accuracy is 0.3203 mm, with the input light polarization being changed in the range from 0° (P type) to 90° (S type).
Źródło:
Metrology and Measurement Systems; 2022, 29, 4; 737--749
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase response of polarization-maintaining optical fiber to temperature changes
Autorzy:
Kyselak, M.
Dvorak, F.
Maschke, J.
Vlcek, C.
Powiązania:
https://bibliotekanauki.pl/articles/173787.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fiber sensor
polarization maintaining
optical fiber
observable Poincare sphere
birefringence
temperature field disturbance
Opis:
This paper deals with the phase shift development in the polarization-maintaining fiber owing to different temperatures of an applied defined body, where both polarization axes are excited. A variation of the Stokes parameters induced by the phase shift is expressed by the Jones matrix and a depiction on the observable Poincaré sphere. The temperature response of polarization-maintaining fiber and the effects of heat transfer on the phase shift variation of polarization-maintaining fiber were described theoretically. The time dependence of the phase shift development and its direction of rotation on the observable Poincaré sphere was measured and presented graphically. In addition, different response measures for higher and lower temperatures compared with the ambient temperature were experimentally evaluated.
Źródło:
Optica Applicata; 2017, 47, 4; 635-649
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A design framework for rigorous constrained EM-driven optimization of miniaturized antennas with circular polarization
Autorzy:
Bekasiewicz, Adrian
Koziel, Slawomir
Powiązania:
https://bibliotekanauki.pl/articles/220503.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
axial ratio
antenna miniaturization
circular polarization antenna
constrained optimization
EM-driven design
Opis:
Compact radiators with circular polarization are important components of modern mobile communication systems. Their design is a challenging process which requires maintaining simultaneous control over several performance figures but also the structure size. In this work, a novel design framework for multi-stage constrained miniaturization of antennas with circular polarization is presented. The method involves sequential optimization of the radiator in respect of selected performance figures and, eventually, the size. Optimizations are performed with iteratively increased number of design constraints. Numerical efficiency of the method is ensured using a fast local-search algorithm embedded in a trust-region framework. The proposed design framework is demonstrated using a compact planar radiator with circular polarization. The optimized antenna is characterized by a small size of 271 mm2 with 37% and 47% bandwidths in respect of 10 dB return loss and 3 dB axial ratio, respectively. The structure is benchmarked against the state-of-the-art circular polarization antennas. Numerical results are confirmed by measurements of the fabricated antenna prototype.
Źródło:
Metrology and Measurement Systems; 2019, 26, 1; 41-52
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The polarization and coherence behavior of the flat-topped array beam through non-Kolmogorov turbulence
Autorzy:
Golmohammady, Shole
Ghafary, Bijan
Powiązania:
https://bibliotekanauki.pl/articles/173578.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
non-Kolmogorov turbulence
flat-topped array laser beam
polarization
coherence
intensity distribution
Opis:
In the present paper, investigation on the polarization and coherence fluctuations of a flat-topped array beam in non-Kolmogorov atmospheric optics links has been presented. For this purpose, the spectral degree of polarization and coherence at the receiver plane is analytically formulated via the extended Huygens–Fresnel integral and the unified theory of polarization and coherence. The influences of the laser beam parameters and the power law exponent that describes the non-Kolmogorov spectrum of the statistical propagation properties of a partially coherent flat-topped array laser beam has been studied in detail. For the employed parameters, it can be concluded that the increase in the structure constant of turbulence (which is equivalent to the increase in turbulence strength) leads to a fast reduction in the spectral degree of coherence. Moreover, when the power law exponent is 3.1, the spectral degree of coherence exhibits a minimum value in comparison with the Kolmogorov atmospheric turbulence.
Źródło:
Optica Applicata; 2019, 49, 1; 75-88
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization dependence of stimulated Brillouin scattering-based switchable microwave photonic filter
Autorzy:
Gu, Jun
Wang, Fei
Lu, Youxi
Peng, Mengmeng
Shi, Lun
Kang, Wen
Huang, Jingxin
Powiązania:
https://bibliotekanauki.pl/articles/173837.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
microwave photonic filter
stimulated Brillouin scattering
polarization dependence
Opis:
We propose and experimentally demonstrate a switchable microwave photonic filter based on polarization dependence of stimulated Brillouin scattering (SBS). The continuous optical wave from a tunable laser source is split into two branches. One branch serves as the SBS pump source and another branch serves as the signal source which are interactional to generate the SBS effect in the dispersion-shifted fiber. Only by adjusting the polarization direction of pump light and signal light, a frequency response switched between bandpass and notch filtering shape can be obtained.
Źródło:
Optica Applicata; 2019, 49, 1; 5-11
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tunable terahertz all-dielectric linear-to-circular polarization conversion metasurface
Autorzy:
Ju, Xiacao
Wang, Weiguang
Liu, Bingchao
Hou, Yanzhao
Wen, Huashun
Yang, Daquan
Powiązania:
https://bibliotekanauki.pl/articles/2172858.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
terahertz waves
dynamically tunable
strontium titanate
polarization conversion
all-dielectric metasurface
Opis:
Terahertz (THz) linear-to-circular (LTC) polarization conversion plays a crucial role in imaging and 6G wireless communication. This paper will give an account of a thermally tunable THz LTC polarization converter by using the active all-dielectric metasurface. It consists of zirconium oxide (ZrO2) microsphere resonators, active strontium titanate (STO) cladding, and flexible polyimide substrate. Through numerical simulation, the amplitude of the ellipticity of the proposed polarization converter at 0.265 THz is –1, indicating that perfect right-hand circular polarization (RHCP) wave is achieved. Meanwhile, the amplitude of the ellipticity is less than –0.8 between 0.247 and 0.278 THz (relative bandwidth is 12%). In addition, with the temperature changes of 180 K (from 200 to 380 K), the operating frequency of the converter can be tuned from 0.220 to 0.291 THz, a sensitivity about 39 GHz/100 K is achieved. Besides, the modulation depth of the ellipticity amplitude can achieve 92% at 0.220 THz, which demonstrates that the converter can output terahertz wave with different polarization states, and the device can be fabricated on a large scale. These perfect conversion performances show that the converter has potential applications in high-speed communication and imaging.
Źródło:
Optica Applicata; 2022, 52, 4; 551--563
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In-fiber Mach–Zehnder interferometer based on polarization-maintaining fiber for displacement and temperature sensing
Autorzy:
Cheng, Jun-Ni
Jiang, Xiao-Yan
Powiązania:
https://bibliotekanauki.pl/articles/2202764.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
displacement sensing
polarization-maintaining fiber
graded-index multimode fiber
Mach-Zehnder interferometer
Opis:
A displacement sensor based on polarization-maintaining fiber has been proposed and proved in experiment. The polarization-maintaining fiber (PMF) is sandwiched with two graded-index multimode fibers (GI MMF), which form the Mach–Zehnder interferometer (MZI) sensor. Graded-index multimode fiber serve as an optical coupler for modes conversion. The results show that with the increase of displacement, the spectrum moves to the long wavelength direction, but when temperature increases, the spectrum has a red shift, which means that the displacement and temperature can be measured separately according to the wavelength drift direction. The sensor consists of 4 mm GI MMF and 14 mm PMF, which can exhibit the displacement sensitivity of –9.275 pm/μm in the range of 0–600 μm. In addition, temperature will also affect the sensitivity of displacement measurement, so the sensitivity of the sensor to temperature is also measured. The results show that the selected monitoring dip provides a better temperature sensitivity of 33.605 pm/°C in the range of 35–75°C. The sensor is easy to fabricate and does not has any functional coating, which make it become a good candidate in the industrial field.
Źródło:
Optica Applicata; 2023, 53, 1; 21--33
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in the states of polarization of random electromagnetic beams in atmospheric turbulence
Autorzy:
Li, J.
Zhao, K.
Lai, Y.
Powiązania:
https://bibliotekanauki.pl/articles/174110.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
non-Kolmogorov atmospheric turbulence
random electromagnetic beams
degree of polarization
orientation angle
degree of ellipticity
Opis:
Taking the random electromagnetic cosh-Gaussian beam as a typical example of random electromagnetic beams, the analytical expressions for the cross-spectral density matrix element of random electromagnetic cosh-Gaussian beams propagating through non-Kolmogorov atmospheric turbulence are derived, and used to study the changes in the states of polarization (degree of polarization, orientation angle and degree of ellipticity) of random electromagnetic cosh-Gaussian beams in non-Kolmogorov atmospheric turbulence. It is shown that the states of polarization of random electromagnetic cosh-Gaussian beams in non-Kolmogorov atmospheric turbulence are different from those in free space. The degree of polarization decreases, and the orientation angle and degree of ellipticity increase with increasing structure constant. The on-axis degree of polarization and the degree of ellipticity appear to have an oscillatory behavior and the orientation angle has a rapid transition for the larger cosh-part parameter of random electromagnetic cosh-Gaussian beams in atmospheric turbulence.
Źródło:
Optica Applicata; 2017, 47, 1; 51-62
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
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