Polarization Definition and 666 Threads

  1. Y

    Plotting polarization of EM waves in Matlab

    Hello , there is a polarization matix I want to implement in matlab. I have build a basic matlab plot which could visualize EM waves in 3D. The basic equations described in equation 2.5.1 from the attached link. given the simple case of linear polarization, What is the strategy of plotting...
  2. M

    A Polarization in a 3 level system

    Hello! I am asking this question from a molecular physics perspective (i.e. diatomic molecule placed in an external electric field), but it's quite general in terms of the formulation. I have a 2 level system (call the levels ##\ket{0}## and ##\ket{1}##) that can be connected by an electric...
  3. Kostik

    A Electric and magnetic field lines in a plane wave of finite extent

    In an infinite plane wave propagating in the ##z## direction, the momentum density is ##\mathbf{p}=(4π)^{-1}(\mathbf{E} × \mathbf{B})## which points in the ##z## direction; therefore, the angular momentum density about the ##z##-axis ##\mathbf{L} = \mathbf{r} × \mathbf{p}## has no...
  4. L

    I Simulation of CHSH inequality experiment in Excel

    I would like reviews of the CHSH inequality experiment simulation, that I have created in excel. This is an open share, you can access anonymously in a private browser session. https://1drv.ms/x/s!Arfr_5NFNXw8aPC38X3LUGQI7oU?e=hDQTof The simulation follows setup as per those listed here -...
  5. S

    Confused about interefence patterns

    # I am confued with what is meant when it says "about the line AB", does this mean horizontally or vertically? The question states that the sources produce vertically polarised microwaves (I know this is relavant) and I also know that waves moving in different planes cannot interfere. Does it...
  6. ergospherical

    I Why isn't TT gauge over constrained?

    In linearised theory, the polarisation tensor ##A_{\mu \nu}## (defined through ##\bar{h}_{\mu \nu} = A_{\mu \nu} e^{ik_{\rho} x^{\rho}}##) transforms under a gauge shift ##x \mapsto x + \xi## with a harmonic function ##\xi_{\mu} = X_{\mu} e^{ik_{\rho} x^{\rho}}## like: $$A'_{\mu \nu} = A_{\mu...
  7. elou

    B How to build a simple polarization filter

    For that we will need a laser pen and two square pieces of opaque, non reflecting material. In both these squares a slit will be cut, wide enough to let a beam of the laser pass through without any refraction effects. First, after the laser has been turned on, one of the squares is placed in...
  8. ZX.Liang

    I What is “absolute circular polarization fraction” for a pulsar?

    In a pulsar paper, two terms were mentioned: circular polarization fraction and absolute circular polarization fraction. 1. What is the absolute circular polarization fraction? 2. What is the difference between them?
  9. Christian Thom

    I Problem with the polarization of entangled photons

    Consider this thought experiment : we use a source of identically vertically polarized photons, such as produced by a type 0 SPDC. One beam go to Alice and the second to Bob. 1. Whatever measurement Bob makes on its beam, if Alice use a vertically polarized detector, all photons are detected...
  10. B

    I Can the Last Maxwell's Equation Explain Polarization of a Wire's Insulator?

    Hi there! Recently, I have been reading about polarization of a wire's insulator. First of all, I want to see a connection between the last Maxwell's Equation: $$\nabla\times\\B\ =\mu_0\ J\ +\mu_0\ \epsilon_0\ \frac{\partial E}{\partial t}$$ and the polarization. So I draw a simple cartoon...
  11. J

    I How to distinguish between diagonal vs horizontal/vertical polarization?

    I have been working for some time on designing an experiment and have gotten stuck on one particular aspect. I would greatly appreciate any advice that can be offered. I'm using SPDC to produce two polarization-entangled photons. Through the course of the experiment I know that one of the...
  12. Frigorifico9

    I How different is a calcite crystal from a polarizer?

    First of all, I apologize if I use incorrect terminology or I express myself poorly, I am trying my best. That said, I hope you guys are smart enough to understand me despite my shortcomings I know that calcite has birefringence, and I know that if you take calcite crystals and cut them and...
  13. Frigorifico9

    I Is Calcite a parallel to the Stern-Gerlach experiment?

    When light passes through Calcite it is split into two beams opposite polarizations, doubling the image, and this sounds very similar to the Stern-Gerlach experiment where atoms are split into two beams with opposite polarizations The difference is that with light the opposite polarizations are...
  14. L

    How are polarization test cards created for proving polarized glasses?

    I could swear I saw this topic in the forum in the past but haven't found it today. I was curious how polarization test cards are made to prove that a pair of glasses are polarized. Special ink or paint? What is that type of substance called or commonly used for? I'd love to use it for art. Does...
  15. ZX.Liang

    I Circular polarization and linear polarization of pulsars

    Is there more circular polarization or linear polarization in the radiation flux of pulsars? Have any papers discussed this issue?
  16. P

    I Is there a generator of entangled photons with fixed polarization?

    Hello everyone! I don't know where to look for information - maybe here it will work :) Is there a generator of entangled photons with fixed polarization? If not, is it theoretically possible to build or is it against the laws of physics. I need this knowledge for further computer...
  17. Leureka

    I Hidden phase in polarization tests of Bell's inequality?

    Hi there, i must preface with saying my understanding of the problem is limited to undergraduate quantum mechanics, since my spacialization is chemistry. I know the basic principles, like hilbert spaces, vector bases etc... I'm only asking this question because i genuinely want to understand...
  18. Cerenkov

    B B-Modes in CMB Polarization - any change since BICEP2 in 2015?

    Hello. I was wondering if there have been any further developments on the topic of B-modes in the CMB polarization since this 2015 paper? https://arxiv.org/abs/1502.00612 A Joint Analysis of BICEP2/Keck Array and Planck Data The above paper declares that... 'We find strong evidence for dust...
  19. sinus

    I How Does Light Remain After Polarization Despite Changes in Its Electric Field?

    I'm studying optics in this semester and one of the topic is polarization of light. Please help me. For ease of understanding we only consider the electric field E, right? I'm confused, if light passes through a polarizer then there will only be one field whose direction of vibration is only...
  20. F

    I What happens when circular polarization meets a diagonal polarizer?

    I'm finding what seems to be conflicting information on this question and could really use some help. It's my understanding that circularly polarized light is composed of two perpendicular linearly polarized components with a 90 degree phase shift between them. When considered individually...
  21. DrChinese

    A How Many Hidden Variables Would It Take to Model Photon Polarization?

    Suppose the EPR* concept were true as it would be applied to entangled photon polarization. (Please note: I am not saying it is.) They thought QM was incomplete, because there must exist "elements of reality" (hidden variables) that supplied the highly correlated results on entangled particle...
  22. M

    Induced polarization for collision between conducting spheres

    For this part (b) of this problem, The solution is, However, would a better explanation be: As the spheres are conductors, there will be free electrons within and on the surface of the conductors that will be polarized by the external electric field between the conductor. This will decrease...
  23. F

    B How to evaluate whether a photon's polarization is in superposition?

    Is there an accepted experimental methodology for determining whether a photon's polarization is in superposition or not?
  24. Spathi

    I Understanding Light Polarization: An Intuitive Explanation

    In this thread, I set out an analogy illustrating what quantum entanglement is; further in my post there is a description of the experiment with polarizers and waveplates, corresponding to this model (CHSH inequalities). To understand it, you need to understand what polarization is. I have read...
  25. M

    I Polarization in Rabi oscillations

    Hello! I have 2 levels, with quantum numbers ##(J=0,m_J=0)## and ##(J=1,m_J=1)## and I am a bit confused about whether I can drive Rabi oscillations between them with a fixed laser polarization. Assuming I start in the ##(J=0,m_J=0)##, I would need right-circularly polarized light to drive that...
  26. sol47739

    I Polarization of photons quantum mechanically

    What is it of the photon that gets polarized from a quantum mechanical perspective? In the classical perspective it is often thought that it is the oscillating electric field that gets polarized. But in the quantum case: Is it the de Broglie wave function? Or is it the spin and in case it is the...
  27. forever_physicist

    A Selection rule for spectra with circular polarization

    Hello everybody! I have a silly question that is blowing my mind. When there is a circular polarized electric field, it can be interpreted as the real part of a complex field, for example $$E(t) = E_0( \hat{x}+i\hat{y}) e^{-i\omega t}$$ Now, for some selection rules it is useful to calculate the...
  28. nomadreid

    Selection rules in electron transitions

    Not sure if this belongs in Chemistry or Physics. Even less sure if I understand the selection rules for electron transition correctly; hence this question. So I would be grateful for someone to please correct the following: Letting n and m be energy levels An electron that absorbs a photon...
  29. A

    I Question about polarization of light by scattering in the atmosphere

    My book says: I don't understand why the bottom eye only sees the horizontal red arrow and not the other angles (black arrows)
  30. Ahmed1029

    I Dipole moment of a cylinder of uniform polarization

    If I want to calculate the dipole moment of a dielectric cylinder of uniform polarization perpendicular to its axis, I could multiply the polarization by the volume of the cylinder, which is okay. But another method is to consider the cylinder to be a superposition of two cylinders of equal and...
  31. ynyin

    I Rotating Polarization with Optics: Exploring the Principle

    In optics experiments, I often see the following optics configuration to rotate the polarization of an incident linearly-polarized laser beam. The final reflected beam has its polarization rotated by 90 degrees. My question is: 1) Between the quarter plate and the mirror( reflecting surface)...
  32. mohamed_a

    I Polarizing filter synthesis and dynamics

    I have found a fair amount of sources for studying polarized light but I haven't found sources discussing synthesis of polarizers in detail along with mechanistic discussion.
  33. M

    B Exploring the Impact of Photon Polarization on Electron State Changes

    How does the polarization of a photon impact the state change of an electron that absorbs it? Presumably the change of an electrons state (including spin) differs based on the polarization of the photon it absorbs.
  34. H

    I Understanding the Expression for a Linear EM Wave Transmission?

    Hi, I have an expression in my textbook that I don't really understand. I have 2 questions regarding this expression for a linear EM wave## \tilde{\vec{E_{0i}}} = (E_{0x} \hat{x} \pm E_{0y} \hat{y}) e^{i(kz- \omega t)}## ## \tilde{\vec{E_{0t}}} = (\sum_j E_{oij} e_{pj}) \hat{e_p} ## ##...
  35. B

    Characterizing an unknown eliptical polarization

    In reality I don't have access to the lab thanks to covid, so I was told that the exiting beam is linearly polarized at +12 degrees when the waveplate is rotated to +70 degrees. I tried plugging these numbers in but got back a complex number for the first component in the Jones vector, when it...
  36. H

    The polarization charge density ##\rho##p in a charged dialectric

    Hi, I have a dialectric cube and inside the center of the cube I have a part where we have Introduced evenly electrons. I have to find the polarization charge density in the 3 regions. I know outside the cube is the vacuum, thus ##\vec{P} = 0## and inside the dialectric (non charged part)...
  37. Sophrosyne

    B Polarization of a single photon

    I was just reading on this forum (and other sources) about the relationship between photon spin and the polarization of light. From what I have gathered, photon spin corresponds to circular polarization: +1 and -1 spins correspond to right and left helical polarizations. So I have a few...
  38. F

    I Electric field of uniformly polarized cylinder

    Hi all, I have a doubt when calculating the electric field of a uniformly polarized cylinder P along its longest axis. The cylinder has length L and radius a. Using Gauss's law: $$\int D\cdot ds = \rho_{f} =0 \, \, (eq .1)$$ The electric field inside of cylinder would be: $$E =-...
  39. bboo123

    I Exploring the Impact of Dielectrics on Electric Flux Density

    In the 7th edition of the book "Elements of Electromagnetics by Matthew N. O. Sadiku" On page 190 the author goes on to say: "We now consider the case in which the dielectric region contains free charge. If ##\rho_v## is the volume density of free charge, the total volume charge density...
  40. E

    A Trace of Numerator in QED vacuum polarization

    Sorry I just typed out my query .For some reason I can't seem to find the buttons for attaching files on this thread. When writing the QED vacuum polarization loop, the numerator ,consisting momenta slashed + m from the fermion propagators and the two gamma matrices, has a trace over all of it...
  41. K

    I Pauli-Villars regularization for Vacuum Polarization

    Hello! I am currently reading Itzykson Zuber QFT book and on Chapter 7 where for the first time loops are considered. Particular method of dealing with divergences namely Pauli-Villars regularization is considered in section 7-1-1 considering vacuum polarization diagram. I do understand physics...
  42. J

    Understanding the Interaction Between a Charged Rod and a Metal Sphere

    (A) incorrect, because opposite signs attract, and the sphere would've been drawn to the charged rod. (B) correct, according to the answer key, but if the charge of the sphere and the charge of the rod are the same, then wouldn't they repel each other? I'm confused as to why this is the correct...
  43. P

    A Gravitational Quadrupole Formula: Polarization Tensor

    In "Gravitational radiation from point masses", by Peters & Mathews, http://gravity.psu.edu/numrel/jclub/jc/Peters_Mathews_PR_131_435_1963.pdf, the emitted power from gravitatioanal quadrupole radiation per unit solid angle ##\Omega## is given by: $$ \frac{dP}{d\Omega} = = \frac{ G} {8 \pi c^2...
  44. Erik Ayer

    I Question on circular polarization and the quantum eraser

    Looking at the wikipedia page for the (original) quantum eraser (https://en.wikipedia.org/wiki/Quantum_eraser_experiment), quarter-wave plates in front of the slits change photons from being linearly polarized to being circularly polarized. I think this is the case when there is no polarizer in...
  45. greg_rack

    Rotation of the plane of polarization of light by glucose

    Hi guys, Online I found this really cool experiment that uses a glucose solution(e.g. in a beaker) to rotate the plane of polarization of a polarized light beam passing through it, of an angle ##\theta## which depends on the frequency of the EM wave. Then, for example, watching white light...
  46. K

    Calculating the degree of polarization of reflecting light

    I am looking for in an equation that's spits out the degree of polarization of reflected light, with incidence angle and the refractive indexes as inputs. an article online article had this graph decribing the degree of polarization as a value between 0 and 1 plotted against the angle of...
  47. lomidrevo

    I Polarization mode symmetries of massless particles

    I am just reading Carroll's textbook on GR, where at the end of chapter 7.4 Gravitational Wave Solutions he discuss how rotational symmetries in polarization modes are related to spin of massless particles. He then explains that we could expect associated spin-2 particles to gravity - gravitons...
  48. X

    Polarization of EM waves is preserved after reflection/refraction -- Why?

    Hello, here's my question: during the usual derivation of Fresnel's equations, it is assumed that an incident EM wave (plane monochromatic) is transverse electric or magnatic and that it keeps this nature after reflection and transmission. How can this be proven? Thank you!
  49. R

    Electrostatic Induction in Metals vs Insulators

    If we have a small dielectric sphere and a point charge, they will experience an attractive force due to electrostatic induction. (From the elongation/rotation of charges bound to individual atoms). Likewise, if we have a small metallic sphere and a point charge, they will experience an...
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