Polarization Definition and 613 Threads

Question: We want to rotate the direction of polarization of a beam of light through 90 degrees by sending the beam through one or more polarizing sheets. (a) What is the minimum number of sheets required? (b) What is the minimum number of sheets required if the transmitted intensity is to be...

Hello, I am trying to determine how an electromagnetic wave changes polarization upon reflection off of an arbitrary object. Here are my confusions in particular. 1. My assumption is that the change in polarization is very much dependent on the geometry of the object, but I don't know the...

Homework Statement Plate capacitor with distance between plates 'd=4mm' is fully filled with homogeneous linear dielectric. Capacitor is connected to the source of DC voltage, first stationary state is established, then the capacitor is separated from DC voltage source. After that, dielectric...

Let's say I have a linearly polarized laser beam, and I focus it to a small spot using a parabolic mirror. Does the light retain its polarization at the focal point? Why or why not? I understand that flat mirrors and concave/convex mirrors preserve linear polarization, and I would like to make...

Hi, if the laser emits polarized light, then why we use polarizer infront of laser?

Hi all, To me, polarization is the most confusing concepts in optics to me. From the text, it is said that polarization is how the light oriented. A linear polarization means the light is oriented on one direction. But I have few doubts I learn from the book and online materials 1) In most...

The QED theories merely state that a photon has spin and momentum. Are there any reasonable mechanistic descriptions, perhaps in terms of variations of E and H beyond the infinite plane wave (which is also not helpful)?

So just to clear things up before we start, does vacuum polarization occur randomly, or does it just occur when an electromagnetic field is present? Also, how would vacuum polarization conserve energy - does it take energy from the field or does it emit negative energy gravity waves or...

Homework Statement An infinitely long dielectric cylinder with radius R and relative permittivity ##\epsilon_r## contains a free charge density given by: ##\rho(s)= ks## for s<R and 0 for s>R, where k is a constant. Find the polarization P and any volume or surface polarization charge...

Hi there, In the decay of ## B \to D^* l \nu ##, I found that the polarization vectors are described as following: In the B rest frame the helicity basis ## \bar{\epsilon}(0)= \frac{1}{\sqrt{q^2}} (p_{D^*},0,0,-q_0), \\ \bar{\epsilon}(\pm)=\pm \frac{1}{\sqrt{2}} (0,\pm 1,- i,0), \\...

Homework Statement Elliptically polarized light, where the rotation of the ellipse is ##\pi/6## and its major axis is ##2E_0## and minor axis ##E_0##, is left through a polarization foil. The foil transmits light in ##x## axis (a) and in ##y## axis (b). Calculate the ratio of transmitted light...

In A. Zee "QFT in a nutshell" in chapter I.5 Exercise 1.5.1 on page 39 for spin 2 massive propagator. I know I’m missing something very simple (self-taught beginner). I'm trying to derive equation (13) on page 35, which is G_{\mu\nu,\lambda\sigma} = G_{\mu\lambda}G_{\nu\sigma} +...

I am trying to understand circular polarization and Real 3D glasses.I am sure that answers will lead to other questions. Question 1. Are Real 3D glasses merely quarter wave plates with each eye set at 90 deg angles to the other? or.. Question 2. Do Real 3D glasses consist of a linear...

Hello. What is troubling me is I can't stabilish a connection. and it seems to be it should exist, between the polarization of a material by displacement of the electron cloud and energy level transition in a molecule or solid. When an electric field is applied to a material, the "electronic...

Homework Statement Two polarizing sheets have their transmission axes crossed so that no light gets through. A third sheet is inserted between the first two such that its transmission axis makes an angle θ with that of the first sheet. Unpolarized light of intensity I0 is incident on the first...

Is there any relation between refractive index and polarization?

From what I understand, neurons at rest are in a state of polarization, with Na+ ions abundant on the outside of the cell and K+ ions abundant on the inside of the cell. During depolarization, sodium ions rush in, creating a highly positive charge on the inside of the cell relatively to the...

Hi pf, I am trying to find answers to the following two questions about polarization of light but am struggling to find anything: 1) When unpolarized light strikes the surface of water, some of the reflected light is horizontally polarized. I was trying to find out what causes this to happen...

I know that a linear voice coil is polarized from top to bottom, but how is a flat coil polarized? Would a flat coil be polarized from the inside to the outside? Where the inside(blue) is one pole and the outside(red) is the other? If you were to do multiple windings(stacked layers) would it...

Hi all, I am wondering how is it possible that the polarization effects of a dielectric material remain confined inside the material itself. That is: for a LIH dielectric, the equations state that the electric field inside the material is reduced by \epsilon_r. But outside the material, no...

I read in few places that the virtual photons have longitudinal polarization while in some papers they say virtual photons have both transverse and longitudinal polarizations. Can anyone please help me to understand this

Homework Statement Evaluate the matrix elements ## {\mathbb S}=\left( \begin{array}{cc} \langle x|\mathbb{\hat J}_z|x\rangle& \langle x|\mathbb{\hat J}_z|y\rangle\\ \langle y|\mathbb{\hat J}_z|x\rangle &\langle y|\mathbb{\hat J}_z|y\rangle\end{array}\right)## by expressing the linear...

I finished my online E&M class today, and the prof told us to experiment with polarizers. While doing that, I found this: I put a piece of plastic between two polarizers, and found that at a certain angle between the two polarizers, a portion - though not all - of the plastic darkened. So I...

So I just started Physics 2 Electricity and Magnetism and I'm already scared for my life. The professor first did a demonstration where he charged up a Teflon rod on some sort of cloth and moved an aluminium can with the rod. I understand how that happens. The can is a metal and conductor so the...

I read once (I don't remember exactly where) that X-rays scattered perpendicularly to the direction of the incident X-rays are linearly polarized (even although the incident ones are not). I think the discussion was in the context of low energy X-rays, and the explanation used classical...

Bonnes fetes de Noel. When an excited electron returns to its ground state a photon is emitted. Suppose that the electron's spin skip from +1/2 to -1/2 (around z)and that the photon has a momentum parallel to z. I suppose that this photon has a circular polarization around z (Is it true?) The...

Hi, I'm thinking the following scenario. I have some solution in a container, where polymers are dissolved inside. If left so, the polymer will be homogeneous in the liquids. Now I add an electric field on the two sides of the container, will the polymers be polarized and stretched? So the...

For internal photon states, is it necessary to sum over the longitudinal polarization state in addition to the transverse states? And if so, does the ordinary Feynman-gauge propagator take care of this? Thanks!

http://www.iflscience.com/physics/physicists-develop-reversible-laser-tractor-beam-functional-over-long-distances In this article, they said they could control the particle's direction by changing the laser's polarization. Could someone explain this to me? I have to do a presentation on it...

Hello, Given an electromagnetic wave that is, from a classical point-of-view, not circular polarized. Does that correspond in QM to photons with the ZERO spin eigenstate? Thanks in advance.

Homework Statement Hi! The entire problem is this: (a) Two plane-polarized harmonic plane waves having the same propagation constant are polarized, respectively, along two perpendicular directions. Show that if the phases of the two waves are different, their superposition yields generally an...

Ok, so I keep reading about these concepts and every source says something different. Even within the same textbook, it says conflicting things. So you have a circularly polarized light that is coming TOWARDS you. That is considered left-circularly polarized or right-circularly polarized? I've...

i have the following questions: Bell inequalities use spin 1/2 matrices and experiments use photons. Is then the electric field horizontal or vertical after the measurement with a polarizer in other words can we assimilate the orientation of the field with a vector in the hilbert space ? How...

Hi, I understand that the α in the form below refers to angle of E-vector to the horizontal. and that a jones vector should be represented this way: I tried to represent the linearly polarized sin & cos form in the jones vector form I know I'm doing something wrong because a linearly...

Who knows where this formula comes? $$ e_i \otimes e_j + e_j \otimes e_i - \frac{2}{3}( \sum_{\substack{k}} e_k \otimes e_k )\delta_{ij} $$

In this paper, the Orbital Polarization (OP) is defined as: $$OP=\frac{n_{x^2-y^2}-n_{z^2}}{n_{x^2-y^2}+n_{z^2}}$$ where $$n_i$$ is the occupancy of that given orbital. I would like to understand the physical meaning of this. Also, is there a difference between OP and Orbital Hybridization?

Hello, I'm currently going through Agrawal's book 'Nonlinear Fiber Optics' and got stuck with some mathematical cosmetics (pp. 40). It is the substition of: \vec{P_L}(\vec{r},t) = \frac{1}{2} \hat{x} \left(P_L \exp{(-i \omega_0 t)} + c.c.\right) into \vec{P_L}(\vec{r},t) = \epsilon_0...

I've been trying to understand the whole BICEP story. Here's what I think I understand so far: Inflation produces primordial gravitational waves. During recombination, photons decouple from matter and the CMB is formed. Propagating gravity waves stretch space in one direction and squeeze it in...

Phase difference between two component of Electric field vector seems to me that the phase difference for circular should be of odd multiples of 90 but its not 90 when n value substituted. Please help for solution..

Homework Statement Unpolarized light is reflected internally in the point P in a glass prism. When the prism is located in air, β is the critical angle of total reflection. I am going to calculate for the following problems: a) If the prism is submerged into water the reflected light becomes...

Hello folks, I've just started to read "An Introduction to Quantum Field Theory by Peskin and Schroeder" and at the end of 6th page I could read: "... Since H_I should conserve angular momentum, the photon to which these particles couple must have the correct polarization vector to give it...

Hi, I would like to know what the theoretical implication is, as it pertains to RC circuits of the following hypothetical situation(s): If one were to connected an ideal discharged capacitor in parallel with an ideal voltage source with zero resistance in the loop, the calculated RC time...

http://en.wikipedia.org/wiki/Brewster%27s_angle The dipoles that produce the transmitted (refracted) light oscillate in the polarization direction of that light. Why? Does that last sentence actually say no light is reflected back if the angle of impact is orthogonal to the surface?

hi, What is the difference between radial polarization and optical vortex? thx http://en.wikipedia.org/wiki/Radial_polarization http://en.wikipedia.org/wiki/Optical_vortex http://en.wikipedia.org/wiki/Angular_momentum_of_light http://en.wikipedia.org/wiki/Orbital_angular_momentum_of_light...

Initial assumptions : 1. An unpolarised photon has 50% chance of being transmitted through a linear polariser. 2. When a photon meets a polarizer we subject it to an observation. 3. The effect being that we have forced it to collapse from being in the superposition of the vertical and...

Hello, I am trying to design an experiment where I can calculate the distance at which polarization will not have a measurable effect on a neutral object, from a sphere charged by a Van Der Graaf generator. I am measuring the weight change caused by the polarization of the neutral object with...

Just wondering, in order to polarize a light beam with a wire grid you could also get some difraction in despite of the wire's length, right? And, if so, will the difracted rays also be polarized?

White light is composed of 7 wavelengths. And yet we show white light as one single electrical wave perpendicular to the accompanying magnetic wave. Don't all the waves actually travel separate (though at the same speed)? Also, does polarization of light mean cutting out on the magnetic field...

All the books that deal with the p-n junction under applied bias asume that the same equations used for the equilibrium case (no bias) can be used for the biased case provided that the juntcion voltage V_{ic} is substituted by V_{ic}-V, where V is the applied bias. Although this can seem...

There have been quite a few Bell threads lately, so I have been looking at them and various other sources. I'm missing something... any guidance appreciated. Per Dr. Chinese's, "Once any photon passes through a polarizer lens, its polarization will be aligned exactly with the lens thereafter...