Polarisation Definition and 119 Threads

Homework Statement Consider a beam of unpolarised light incident onto air from a crown-glass with a refractive index of 1.52. Given that the incident light intensity has a power of 10mW, find the minimum incident angle when the power of the refracted light becomes zero. Homework Equations I...

My previous thread on this topic got a bit messy as the gist of the argument was in the middle of the thread and turned out wrong. Hence this new updated version. One of my favourite articles on Bell's Theorem can be found at...

I've seen some articles using particle spin experiments to 'prove' that the results violate Bell's inequality and consequently local reality. I've also seen stated that the same experiments can be done using other particle attributes such as polarisation. I can see how with polarisation, you...

Consider a measurement of a photon after it has passed a polarisationfilter. Does the photon jump in a (polarisation-)eigenstate by passing the filter? Does the filter do a measurement? Is the filter part of the entire measurement?

Consider two polarisation-entangled photons A and B fired at two polarisationfilters that are at a certain angle α. Are the probability that A is passing its filter and the probability that B is passing its filter indepedent probabilities? I am aware that is probably an incredibly stupid...

A dielectric is placed between two capacitors ,How (a) gets transformed into (b) Where did all the dipoles present in picture (a)go?And from where the negative and positive charges appeared inside the dielectric in picture (b)

This may be a dumb question, but maybe someone can help me out: Consider a pair of entangled photons A and B, fired at respectively Alice and Bob who both let it go through a polarisation filter at different angles. Now Alice establishes that half of the photons get through her filter, and half...

Can a rotating dielectric disc be polarized? No external electric or magnetic field .

I thought there were already some posts about this, but I can't find them.:frown: In this article of Anton Zeilinger et al. they perform an experiment which suggests FTL or retrocausal influence. Alice and Bob both produce their own polarisation-entangled photon pair, both send one photon of...

Does magnetic field of lightgets polarised when electric field polarised when passed through a polariser

hi, I'm currently talking about light, and I'm trying to find out if there is a material or a method that can flip a polariser's polarisation... ie, if i apply a current, then this crystal changed from a clockwize polariser to an anti-clockwize polariser, and it is either a plastic or elastic...

I would appreciate if the explanation didn't derive this phenomenon using Malsus' Law exclusively and would go into the horizontal and vertical components of polarized light, and how the blocking of the horizontal components results in a halved intensity...so more of a geometric explanation...

Hi. We can write a polarised photon as ##\left|\alpha\right\rangle=\cos(\alpha)\left|\updownarrow\right\rangle+\sin(\alpha)\left|\leftrightarrow\right\rangle##. Trigonometry gives us $$\left\langle\alpha | \beta\right\rangle=\cos(\alpha)\cos(\beta)+\sin(\alpha)\sin(\beta)=\cos(\alpha-\beta)$$...

I have been trying to mathematically explain the empirical result that putting orthogonal polarisers (quarter-wave plates) behind the two slits of a double-slit setup will erase the interference pattern. The trouble is, my analysis predicts an interference pattern. I must have made a silly...

Let we have a dielectric with field ##E## inside and with a little hole. I have problem. I get a two different answers on this problem, and I try to understand which one of them correct. As mentioned in http://www.feynmanlectures.caltech.edu/II_11.html#Ch11-S4 (11.25), the electric field in...

This question is prompted by a recent discussion I have been following regarding the insertion of a 45 degree angle polariser between two polarisers at 90 degrees to each other. The insertion of the filter seems to restore missing components which would suggest that those components were present...

This confusion is about the following problem: Suppose the entire region below the plane z=0 is filled with uniform linear dielectric material of susceptibility ##χ_e##. Calculate the force on a point charge q situated a distance d above the origin. Now, this problem is done in Griffiths'...

I have been looking up the practical details of certain quantum eraser type experiments and got stuck on a couple of points. I refer to a particular experiment which can be found by googling: "A DOUBLE SLIT QUANTUM ERASER EXPERIMENT" (Sorry I don't know how to include the address) In...

What is the link between the polarisation of light and photon spin?

Question For (i) I assumed that the light was plainly polarised as there is only a difference in amplitude For (ii) There is a negative sign infront of the amplitude which I ignored as it doesn't change the polarisation but one is cos and the other is sin, so there is a phase shift of...

Hi, I have a question regarding the projection of polarised light onto a screen, such as commonly used in 3D or VR cinemas. I'm only concerned with linearly polarised light for the moment. I understand that when light undergoes reflection the polarity is altered. I've attached a diagram...

I have some questions referring to wave plates. We have an entangled pair of photons as |H>|V> - |V>|H> and both go through 22.5 degree orientated half-wave plates. |H> is converted to |45> and |V> is converted to |135> (so the description is now |45>|135> - |135>|45>). So inputting the...

Homework Statement The problem is taken from A Modern Approach to Quantum Mechanics by Townsend, and is stated as follows: The answer given in the back of the book is 0.12, though I have not managed to get this result. Homework Equations Classically, light traveling through a crystal...

I have read about polarisation... just a little ques about concept... in case of circular polarisation there is 90 degree phase difference between the two v and h, e field component... right... and in case of linear polarisation the e field is restricted to oscillate in only one plane...

I have two queries: - if unpolarised light passes through a polaroid filter so that light coming out of the filter becomes polarised, would intensity (brightness) of the light become reduced as a result? - if you have a polarized wave, and it passes through a filter that has a gap which is...

Hello, Are longitudinal EM waves ( I know they exist) any different from linearly polarised waves we learn about in antennae theory Just to be clear http://www.antenna-theory.com/basics/polarization.php defines linear polarisation pretty clearly in the context i am talking about

we know that heat is caused by vibration of molecules. the vibration by nature of molecules is random. but in as in polarized light can we give heat that is vibration a particular direction. then this vibration i call polarized heat has varying temp at various angles. can this be actually...

Homework Statement Plane monochromatic waves are propagating in free space parallel to the x-axis in both positive and negative directions. At the origin the field strengths are given by: Ez = E0 cos wt Ey = 3E0 cos wt cBz = E0 cos wt cBy = E0 cos wt Find the amplitudes and...

I was just wondering if it was possible theoretically to move or attract large/heavy materials using polarisation. For example I've heard examples that if you have a charged rod ,and you bring it close enough to pieces of paper the charge on the rod will polarise the paper and then if that...

Homework Statement E(z,t) = E_{0x} \sin (kz - wt - \frac{\pi }{12}) - E_{0y} \cos (kz - wt + \phi + \frac{\pi}{12}) E(z,t) = E_{0x} \sin (kz - wt - \frac{\pi }{3}) - E_{0y} \sin (kz - wt + \frac{\pi}{6}) The Attempt at a Solution For the first and second problem, I set t and z both to 0, so...

Hello all I know that polarisation of light can occur from reflection, and when the reflected ray is 90degrees from the refracted ray the relfected light is 100% plane polarised. So, my question is why is it that reflection causes polarisation of light? Thanks

I have been studying stereochemistry and it says that optically active molecules(chiral molecules) rotate plane of polarisation. I suppose that's because of the electrons in the molecule. I know that all molecules can rotate the plane of polarisation but when achiral moelcules are present in...

When we use polarisation rotators to measure certain polarisations for entangled photons, the photon usually meets a polarised beam splitter after. When we detect in the |H> or |V> basis, does that mean the photon is in |H> or |V>? What has happened to the polarisation we were measuring...

hi if you have linear polarized light and you have a metal grid and the angle between the e-vector and the metal grid is 30°. now you split up the e-vector in one component parallel and one component perpendicular to the metal grid. okay. so the component of the wave, that survives this...

I am confused by the role of photon polarisation in Bell inequality experiments. The original logic of EPR as I understand it is based on the HUP such that QM predicts that measurement of momentum on one particle should affect the measurement of position of the other particle. Yet across...

Hey guys. I need some help on understand a few concepts and have some questions 1. How is light polarised when it is reflected? 2. Are there different amounts of light vibrating in each direction, or is it equal? 3. From my revision guide: "If you direct a beam of unpolarised...

I was thinking: if you send light through a 45 degree filter (D filter), and then sent that light through another D filter, because it is now in superposition of V+H state, and according to 'Beyond Measure', light in that state (left circularly polarised) would go through the 2nd filter 100% of...

Hi,Homework Statement I have the following question: I found two formulas given for the intensity after polarised light went through a polarisation filter. Homework Equations I_{1}=I_{0}*\frac 1 2 and I_{1}= I_{0}*cos^{2}(\phi) The Attempt at a Solution Well I don't know when to use...

I have been studying polarization in dielectrics recently. I got stuck after coming to Claussius Mossoti equation. I can't understand it's importance. I read that it is used to determine molecular structure but how exactly? I've just joined this forum, hope someone can help. :) TIA P.S: Sorry...

Hi there, mathematician learning a little QM here. I've been watching a few of these lectures: http://www.youtube.com/watch?v=LBFBQr_xKEM&feature=relmfu The lectures are good, a little slow paced for me, but clear at least. He starts talking about polarisation in the last half of...

1.in an intrfrnce expmnt. wit monochromatic light of wavlngth 6000 AU only 50 fringes are observable.estimate d coherence of d source. 2.show a circularly polarised lght is eqvlnt to 2 mutually perpendicular plane polarised lt wit a phase diff of pie/2. 3.fringes of equal inclination are...

I'm looking at a surface at an angle. Light reflected to me is polarised (Fresnel), does this mean light emitted to me from the surface is also polarised? I've been told that ocean emission is polarised (when looking at an angle) because of Kirchoff's law of radiative balance (emissivity =...

Reading around the subject, I get the impression that it is impossible to have full knowledge of the polarisation angle of a photon. For example is a linearly polarised photon passes through a vertical polariser it is said to be "vertically polarised" on exiting the polariser, but in fact all we...

Maybe this is a trivial question, I'm not sure, but when you measure linearly polarised light, such as that in the CMB which component of the light is 'measured'. By this I mean is it the oscillating electric field or the oscillating magnetic field that is oscillating in the direction of the...

Homework Statement A particle of charge 'q' and energy 'E' which experiences an acceleration 'a', emits electromagnetic radiation. Show that the radiation from this particle which is emitted parallel to the magnetic field is expected to exhibit circular polarisation. The Attempt at...

surface plasmons not exist for transverse electric polarisation? and only exist for transverse magnetic polarisation can anyone help meeeeeeeeeeeeeeeeeeee please

In what relation to each other are the direction of spin vector and direction of polarisation vector... for example of a photon ?

Homework Statement "Polarisation" is defined as the cofinement of the vibrations of the wave in only one plane and the removal of the vibrations in the other perpendicualar plane of the electromagnetic wave. But the e.m. wave is defined as a wave in which the electic vetors are restricted...

Hi all. Usually we have worked with electromagnetic waves linearly polarized along the z-direction (or x or y for that matter). Is it possible to have an E.M. wave, which is just polarized along some arbitrary direction r = (x, y, z)T? Or does it necessarily have to be circular or in x, y...

In a textbook on wireless communications that I am reading, the author states that transmissions from a vertically polarised antenna will undergo interactions which would cause energy to leak into the orthogonal polarisation component (Im assuming the H-field of an EM wave) before reaching the...