Questions tagged [polarization]
Polarization characterizes the oscillations in time the electromagnetic field is doing in the plane perpendicular to the propagation direction of a wave
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Derivation of hypercharge neglecting squared amplitude for WZ helicities in paper
I am trying to get from equations (20) and (21) in this paper to equations (13) in this one.
I will start with my attempt at deriving this for the LL case.
(With $F$ from equation (4), $g_2-g_1$ from (...
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Can not follow derivation of $WZ(0, 0)$ amplitude in paper
i am re-reading this paper and trying to follow the derivation of equation (21) from equation (15).
Maybe someone can tell me where i am going wrong.
So the original equation 15 is:
$$M(0,0) = F\frac{\...
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Measuring Stokes parameters leading to a degree of polarisation greater than one
I am trying to measure the stokes parameters of a laser beam using the rotating waveplate method detailed here:
https://pol3he.sites.wm.edu/wp-content/uploads/sites/50/2020/01/measuring-Stokes-...
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Why are Jones vectors normalized?
I have been studying polarization of light, and everywhere I look, one of the main approaches for dealing with polarization of light is by using Jones Vectors.
These vectors describe the polarization ...
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What is the angle for the polarization of a massless spin-$s$ field to be rotated in order to become orthogonal?
For spinless particles there are no states related to spin.
For spin-1/2 particles like the electron, orthogonal spin states are obtained by rotating the state by $\pi$ radians, like in up $\uparrow$ ...
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Electric field produced by a uniformly polarized sphere
I am thinking about the classic problem of a uniformly polarized sphere, within which the polarization is in $z$ direction.
I've been trying to find the electric field inside the uniformly polarized ...
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Why electric field is unaffected due to dielectric shell?
I am reading Grifith Textbook and came across this example(Ex 4.5 in 4th edition).
A charged sphere of radius 'a' is surrounded by a dielectric shell with outer radius 'b' and inner radius 'a'.
Using ...
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What is $E$ with respect to the relation between an electric field and its polarization density?
To avoid confusion let:-
$E_0$ be electric field we applied, $E_p$ be electric field caused by polarization and $E_n$ be net electric field i.e. $E_n = E_0 - E_p$
In the relation
$P=\epsilon_o\chi_eE$ ...
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Are the $H$ and $M$ fields parallel?
I would like to know if the $H$ and $M$ fields are always in the same (or opposite) direction. If not, are there special conditions where it is always true?
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Why are the total and free EM fields mixed together?
For calculating the work done on a medium by an electric field: $đW = \vec{E} \cdot d\vec{P}$ but for magnetic fields: $đW = \mu_0 \vec{H} \cdot d\vec{M}$. For impedance, $Z = \frac{E}{H}$. Why is the ...
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What will be the state of polarization?
When unpolarized light incident on the first polarizer, the light becomes plane-polarized with intensity equal to half of the initial value and the plane of polarization is parallel to the optic axis ...
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Same behaviour of EM radiation at the polarisation grid and at the double slit?
In a diffraction grating, the EM radiation is polarised after passing through the grating, i.e. the electric and magnetic field components are aligned by the grating bars, one component parallel, the ...
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Double refraction in Calcite Crystal
In the above text it is mentioned that the incident light ray travels along the principal section.But any ray which travels along the principal axis should not go through the double refraction. Then ...
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Is unpolarized light necessarily a semi-classical phenomenon?
I'm aware that unpolarized light can be represented by a mixed state $\frac{1}{2}(|x\rangle\langle x| + |y\rangle\langle y |)$. It bothers me that in this framework, unpolarized light is a symptom of ...
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What happens to the electric field of circularly polarized light upon a normal reflection from a mirror?
Let's imagine we have Right Circularly Polarized Light propagating in the $+\hat{z}$ direction toward a perfectly reflecting mirror. Before reflection, the light has the electric field:
$$\vec{E}(z)=...
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Does a process that creates a pair of photons have the same polarization and also the same output of a hidden variable if it existed?
After watching this video on Bell’s inequality here, it mentions that if you have a process for pair production, in this case a photon pair where the photons travel in opposite directions, the ...
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$\vec{E}$-field in toroidal polarized dielectric
In an electrostatic situation, imagine a dielectric torus that is permanently polarized with polarization given by:
$\vec{P} = P(r, z) \hat{\phi}$
(Here cylindrical coordinates are used with the $z$-...
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On counting the DOF of EM wave polarization
I've got a few questions:
In a direvation I've seen, it's 4->3->2: in Lorenz gauge, by solving d'Alembert equation we get $A^\mu=\mathcal{A}\varepsilon^\mu e^{i(kz-\omega t)}$, and $\varepsilon^...
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Will light, from two different (but identical) lasers injected into one end of a long fiber, come out form the other end with the same polarization?
Two beams of light from two lasers of the same type, with the same wavelength but different polarization, are coupled with 2X1 coupler into a 100m long single mode regular fiber. Each laser can be ...
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Physical states in Gupta-Bleuler quantization
I'm reading Timo Weigand notes for Gupta-Bleuler quantization of free EM field.
On page 109, Author has made the following statements.
The Gupta-Bleuler condition for physical state is
$$|\vec{p},\...
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Rigorously deriving the expression for polarization current
Is there a way to properly show that the polarization current associated with a polarization $\vec P$ is $\frac{\partial\vec P}{\partial t}$?
I've seen a lot of heuristic arguments and would ...
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Why does tempered glass show black patterns under polarized light?
I have placed a glass pot lid in-between a polarized white light source and a camera with a linear polarizer. The polarizers are offset by 90 degrees. I'm wondering why the squiggly lines that appear ...
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Confusion regarding on whether to include conduction charges(intrinsic to the material) as a part of bound charges in the calculation of polarization
Consider a semi-conductor in which conduction is mainly due to free electrons(valence electrons that are free to roam throughout the material) , and since it's a semi-conductor say not all atoms ...
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Regarding the (possible)effects of magnetic field on dielectric polarization and the electric fields on magnetization
The dielectric Polarization vector $\vec P$ is related to the macroscopic electric field by the constitutive relation
((source : wikipedia))
Which hints that the Polarization depends only on the ...
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Different derivations of dieletric polarization charges in Griffiths and Feynman
I am reading Griffiths's Introduction to Electrodynamics (3rd edition). In the part of dieletric polarization (p.166), the author first adopts the potential for a single dipole:
$$V(\mathbf r)=\frac{1}...
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Polarization of longitudinal modes of He-Ne laser
I read (in the book Gas lasers and at the site https://www.experimental-engineering.co.uk/helium-neon-lasers/theory-modes-coherence/) that for red (633 nm) He-Ne lasers at least, adjacent ...
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What is this vector notation? For linear retardance calculation
Consider:
I found this formula in https://doi.org/10.1364/BOE.426653 (NLM), a paper titled: Stokes polarization imaging applied for monitoring dynamic tissue optical clearing.
The formula is for ...
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Do the molecules inside a dielectric physically move when the dielectric is polarized by an external electric field?
Today a colleague and I had a heated debate over whether, when an external electric field is applied across a dielectric, the molecules in the dielectric actually move/rotate (flip to align with the ...
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Can we determine the polarization of a neutrino?
I recently read that neutrinos have a polarization property---their polarization is opposite to antineutrinos.
Is it possible to determine the polarization of a neutrino? For example, we can determine ...
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Polarizer that accepts entangled photons
I am having a bit of trouble putting the quantum mechanics of light into physical terms.
You can send unpolarized light into a polarizer; suppose we have a photon in the state:
$| \phi_1 \rangle = x | ...
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Why don't photons align in an electric/magnetic field?
I am familiar with the Faraday Effect, but I am not talking about that. Even though photons do not have any electric charge or magnetic field, they are still composed of oscillating electric and ...
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Why do electric field lines bend towards the normal of a linear homogeneous dielectric sphere?
Why do the field lines of the uniform external field bend towards the normal of the linear homogeneous dielectric sphere as shown in the diagram?
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Formal proof that stacking multiple polarizers does/does not improve the extinction ratio?
Assume that you have a light source, e.g. a laser diode, with a polarization extinction ratio (ER) of 100:1, and you need to improve the extinction ratio as much as possible by adding polarizers, e.g. ...
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Relation between polarization and susceptibility for nonlinear processes
I've been confused about this for a while--
Boyd mentions that the second order polarization is related to second order optical susceptibility as $P_i(\omega_m + \omega_n) = \epsilon_0\sum_{(mn)}\chi_{...
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How was polarization interpreted when first discovered? [closed]
Malus first discovered light polarization just before 1810, but Maxwells equation stuff came around 1860s, so how was polarization interpreted before the EM theory?
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How to find force on point charge due to distributed charge system?
How to find force on charge +q by uniformly charged rod(or ring) of charge +Q. I know how to find electric field but I am confused whether we can use the formula:-
$$F=qE$$
Because the charged object ...
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What does centre of mass of charge mean?
I am unable to understand what does this centre of mass of positive charge and centre of mass of negative charge mean??
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What does centre of positive and negative charge separated by a small distance mean? [duplicate]
I dont understand the meaning of this statement that centre of positive and negative charge is separated by a small distance??
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Onsager's model to investigate the dielectric constants of a pure polar liquid or a solution
I'm trying to understand the article 'Onsager, Lars. Electric moments of molecules in liquids. Journal of the American Chemical Society, 1936, 58: 1486-1493' in which the author wants to investigate ...
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Comparison between Jones vectors and spin state vectors
I'm trying to learn about spinors by myself: I've found what it seems to me a very good series of videos on youtube which explains them starting from basic concepts and examples. Now, in this video, ...
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Schrödinger equation compared to Gauss law for electrostatic polarization?
Consider an electrically neutral isolated metallic sphere in vacuum. Suppose we approach this sphere with a negative point charge. When the point charge is close enough, the electronic density on the ...
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Malus law for gravitational waves
What is the analogue of the Malus law for polarized electromagnetic waves to the cause of plus and cross polarized gravitational waves?
Bonus: What if gravitational waves have further degrees of ...
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Is global phase unknowable or irrelevant?
The E field of a photon is given by $Re\{(a_1 e^{i \phi_1}, a_2 e^{i \phi_2}) e^{i (kz-\omega t)}\}$
If we describe the system in quantum mechanics, then $(a_1 e^{i \phi_1}, a_2 e^{i \phi_2}) $ is the ...
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How to arrive from a spin to a given polarization and what consequences does the solution imply?
Correct me if at any point I'm wrong.
My understanding is that spins up and down are associated with left($L$) and right($R$) circular polarizations of a photon. Then any other polarization $P$ is a ...
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Potential Field in space of a "thick" dieletric spherical shell affected by an uniform electric field [closed]
The spherical linear homogeneous dielectric shell has an inner radius $a$ and an outer radius $b$ and is under the influence of an uniform electric field, then what is the potential across all its ...
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Experimental Demonstration of Entanglement?
In many papers about entangled sources, they use an experimental setup like this one to demonstrate their entanglement:
The setup involves measuring coincidences at the detectors at various angles of ...
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Relationship between polarization $P$ and displacement field $D$?
In a paper https://journals.aps.org/prb/abstract/10.1103/PhysRevB.96.235420, there are following derivation of the relationship. For the free energy, there's an electrostatic energy part, the term is $...
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Why are circular polarized 3D glasses for cinemas so cheap and working for a range of wavelengths?
Does anyone know how the filters in circular polarized 3D glasses for cinemas work (meaning how the filter on a micro-scale works, which material they use...)? Because in the lab we use of course ...
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What information is gained when just one single half of an entangled photon pair is detected, following its transmission through a polarizer?
My admittedly limited understanding of QM is that it is a matter of probabilities whether or not a photon is (re)transmitted through a polarising filter and that these are a function of the relative ...
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Definition(s) of polarization of waves
Is there more than one definition to "polarization" in the context of waves?
In some cases, I've seen the term "direction of polarization", which I presume it refers to the ...
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