scholarly journals Effect of local PMD and PDL directional correlation on the principal state of polarization vector autocorrelation

2003 ◽  
Vol 11 (23) ◽  
pp. 3141 ◽  
Author(s):  
Liang Chen ◽  
Saeed Hadjifaradji ◽  
David Waddy ◽  
Xiaoyi Bao
Keyword(s):  
Polarization Vector ◽  
State Of Polarization

scholarly journals COMPARATIVE ANALYSIS OF THE PROPERTIES OF SODIUM NIOBATE AND SODIUM - LITHIUM NIOBATE CERAMICS

2021 ◽  
pp. 278-285
Author(s):  
Ольга Витальевна Малышкина ◽  
Кирилл Валерьевич Пацуев ◽  
Александра Ивановна Иванова ◽  
Майс Али
Keyword(s):  
Comparative Analysis ◽  
Lithium Niobate ◽  
Polarization Vector ◽  
Sodium Niobate ◽  
Ceramic Samples ◽  
State Of Polarization ◽  
Continuous Mass ◽  
Polarization Gradient ◽  
Individual Grains ◽  
Niobate Lithium

Авторами исследовано влияние температуры синтеза ниобата натрия, на состояние поляризации в образцах керамики чистого ниобата натрия и модифицированного литием. Проведено сравнительное исследование структуры и пироэлектрических свойств полученных образцов. Показано, что введение в качестве модификатора лития приводит к существенному изменению структуры в глубине образцов керамики на основе ниобата натрия. Если в глубине образцов чистого ни ниобата натрия, как и на поверхности, различаются отдельные зерна, то центральная часть керамики ниобата натрия-лития представляет собой сплошной массив, в котором отдельные зерна не наблюдаются. Во всех образцах, кроме чистого ниобата натрия, синтезированного двойным синтезом (первый при 650 °C, второй при 700 °C), установлено существование градиента поляризации по толщине образцов, направленного от стороны, соответствующей положительному концу вектора поляризации к стороне, соответствующей отрицательному концу вектора поляризации. The authors studied the effect of the temperature of sodium niobate synthesis on the state of polarization in ceramic samples of pure sodium niobate and modified with lithium. A comparative study of the structure and pyroelectric properties of the obtained samples has been carried out. It is shown that the introduction of lithium as a modifier leads to a significant change in the structure in the depth of ceramic samples based on sodium niobate. If in the depth of the pure sodium niobate samples, as well as on the surface, there are individual grains, then the central part of the sodium niobate-lithium niobate ceramics is a continuous mass in which individual grains are not observed. In all samples, except for pure sodium niobate, which was synthesized by double synthesis (the first at 650 °C, the second at 700 °C), the existence of a polarization gradient along the thickness of the samples was established. The gradient is directed from the side corresponding to the positive end of the polarization vector to the side corresponding to the negative end of the polarization vector.

The need of electron microscopy in the study of domains and domain walls in ferroelectrics

1994 ◽  
Vol 52 ◽  
pp. 550-551
Author(s):  
Wenwu Cao
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
High Mobility ◽  
Continuum Theory ◽  
Polarization Vector ◽  
Ferroelectric Materials ◽  
Dielectric Constants ◽  
Nonlocal Coupling ◽  
Cubic Symmetry ◽  
Gradient Energy

Domain structures play a key role in determining the physical properties of ferroelectric materials. The formation of these ferroelectric domains and domain walls are determined by the intrinsic nonlinearity and the nonlocal coupling of the polarization. Analogous to soliton excitations, domain walls can have high mobility when the domain wall energy is high. The domain wall can be describes by a continuum theory owning to the long range nature of the dipole-dipole interactions in ferroelectrics. The simplest form for the Landau energy is the so called ϕ model which can be used to describe a second order phase transition from a cubic prototype,where Pi (i =1, 2, 3) are the components of polarization vector, α's are the linear and nonlinear dielectric constants. In order to take into account the nonlocal coupling, a gradient energy should be included, for cubic symmetry the gradient energy is given by,

Method of first integrals and interface, surface waves

2010 ◽  
Vol 32 (2) ◽  
pp. 107-120
Author(s):  
Pham Chi Vinh ◽  
Trinh Thi Thanh Hue ◽  
Dinh Van Quang ◽  
Nguyen Thi Khanh Linh ◽  
Nguyen Thi Nam
Keyword(s):  
Rayleigh Waves ◽  
Displacement Vector ◽  
Attenuation Factor ◽  
Electrical Potential ◽  
Polarization Vector ◽  
First Integrals ◽  
Dispersion Equations ◽  
Interface Surface ◽  
Electric Induction ◽  
The One

The method of first integrals (MFI) based on the equation of motion for the displacement vector, or  based on the one for the traction vector was introduced  recently in order to find explicit secular equations of Rayleigh waves whose characteristic equations (i.e the equations determining the attenuation factor) are fully quartic or are of higher order (then the classical approach is not applicable). In this paper it is shown that, not only to Rayleigh waves,  the MFI can be applicable also to other waves by running it on the equations for mixed vectors. In particular: (i) By applying the MFI  to the equations for the displacement-traction vector we get the explicit dispersion equations of Stoneley waves in twinned crystals (ii)  Running the MFI on the equations for the traction-electric induction vector and the traction-electrical potential vector provides the explicit dispersion equations of SH-waves in piezoelastic materials. The obtained dispersion equations are identical with the ones previously derived using the method of polarization vector, but the procedure of driving them is more simple.

A Novel Technique for Reconstruction of the State of Polarization by Fourier Transform Holography

1998 ◽  
Vol 27 (2) ◽  
pp. 63-69
Author(s):  
Soumika Munsm ◽  
S. Bandyopadhyay ◽  
Ajay Ghosh
Keyword(s):  
Fourier Transform ◽  
The State ◽  
Novel Technique ◽  
State Of Polarization

scholarly journals Frequency-Dependent FDTD Algorithm Using Newmark’s Method

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Bing Wei ◽  
Le Cao ◽  
Fei Wang ◽  
Qian Yang
Keyword(s):  
Differential Equation ◽  
Electric Field ◽  
Field Intensity ◽  
Time Domain ◽  
Difference Method ◽  
Electric Field Intensity ◽  
Polarization Vector ◽  
Solution Stability ◽  
Central Difference ◽  
Central Difference Method

According to the characteristics of the polarizability in frequency domain of three common models of dispersive media, the relation between the polarization vector and electric field intensity is converted into a time domain differential equation of second order with the polarization vector by using the conversion from frequency to time domain. Newmarkβγdifference method is employed to solve this equation. The electric field intensity to polarizability recursion is derived, and the electric flux to electric field intensity recursion is obtained by constitutive relation. Then FDTD iterative computation in time domain of electric and magnetic field components in dispersive medium is completed. By analyzing the solution stability of the above differential equation using central difference method, it is proved that this method has more advantages in the selection of time step. Theoretical analyses and numerical results demonstrate that this method is a general algorithm and it has advantages of higher accuracy and stability over the algorithms based on central difference method.

When elites polarize over polarization: Framing the polarization debate in Turkey – RETRACTED

2018 ◽  
Vol 59 ◽  
pp. 109-133
Author(s):  
Senem Aydın-Düzgit ◽  
Evren Balta
Keyword(s):  
Civil Society ◽  
Qualitative Interviews ◽  
Radical Change ◽  
The State ◽  
Considerable Degree ◽  
Institutional Factors ◽  
Degree Of Polarization ◽  
State Of Polarization ◽  
The Government ◽  
Near Future

AbstractThis article aims to explore the views of the Turkish elite on the state of polarization in Turkey. By identifying four political frames—namely, harmony, continuity/decline, conspiracy, and conflict—that selected Turkish political and civil society elites use in discussing the phenomenon of polarization in the country through their contributions to a workshop and in-depth qualitative interviews, the article finds that there is a considerable degree of polarization among the Turkish elite regarding their views on the presence of polarization in Turkey. Moreover, this overlaps with the divide between the government and the opposition in the country. An analysis of the justificatory arguments employed in constituting the aforementioned frames shows that, while those elites who deny the existence of polarization seek its absence in essentialist characteristics of society, in reductionist comparisons with history, or in internal/external enemies, those who acknowledge polarization’s presence look for its roots in political and institutional factors and processes. The article highlights how, given the denial of polarization by the pro-government elite and the substantial gap between the two camps’ justificatory narratives, the currently reported high rates of polarization in Turkey can, at best, be expected to remain as is in the near future, barring a radical change in political constellations.

Radiation pressure on a dielectric surface

2010 ◽  
Vol 88 (4) ◽  
pp. 247-252 ◽  
Author(s):  
A. Hirose
Keyword(s):  
Radiation Pressure ◽  
Momentum Flux ◽  
Density Wave ◽  
Polarization Vector ◽  
Dielectric Surface ◽  
Dielectric Medium ◽  
Incident Momentum ◽  
New Form ◽  
Intensity Wave ◽  
Wave Momentum

The radiation pressure on an insulating dielectric medium should be calculable from the force acting on the polarization vector P. The well-known force proposed by Gordon (Phys. Rev. A, 8, 14 (1973) disappears in the case of a steady-state plane wave. A new form of force explicitly involving the polarization vector is proposed and applied to determine the partition of the incident momentum among the reflected and transmitted wave, and the dielectric medium. The momentum of electromagnetic wave in a dielectric medium thus found is consistent with the classical relationship, wave momentum flux density = wave intensity/wave velocity.

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