# Polarisation Definition and 43 Discussions

IPS (International Pol Scale) is a price adjustment scale described in the rules of the Sugar Association of London. It defines incremental price premiums and penalties applied to sugar above 96 degrees polarisation. This scale equates that the sugar contains 96% sucrose'

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1. ### I Mirror rotates any polarisation by 90°?

Over each eye is a linear polariser and they are orthogonal to each other. So I conclude from the experiment that the polarisation must have been rotated by 90° by the mirror. That reminded my of phase plates but they only work because their refractive indix depends on the angle. Along two...
2. ### I On 'A Quarter Waveplate (QWP) rotated between 2 Polarisers'

While going through the book 'Problems & Solutions in Optics and Photonics' I was having difficulty in understanding a question & have some issues about my own conceptual know-how in this regard. The Question is: A quarter-wave plate is rotated between two crossed polaroids. If an unpolarised...
3. ### I Observables on the "3 polarizers experiment"

Observables on the "3 polarizers experiment" Hi guys, I was analyzing the 3 polarizers experiment. This one: (first 2 minutes -> ) Doing the math (https://faculty.csbsju.edu/frioux/polarize/POLAR-sup.pdf) I realized that the process is similar to the Stern-Gerlach' experiment. Using spins...
4. ### B How does polarisation in nature work?

Why are lights reflecting off horizontal surfaces like the road, water, or snow horizontally polarized? How does the process happen?
5. ### 3D Cinema Glasses: An Unsolved Personal Experience

Many years ago I went to the cinema to watch Avatar in 3D, and was provided with polarising 3D glasses at the venue. I can't remember if it was my first 3D film that involved polarising projection technology, but it was certainly one of my first. In any case, the 3D effect worked and I got...
6. ### Rotation and Polarisation of Light using Jones Matrices

Hello there I am having trouble with part b) of this exercise. I can apply the rotation matrix easily enough and get: $$R(-\theta) \vec J= \begin{bmatrix} A\cos\theta + B\sin{\theta}e^{i\delta} \\ -A\sin\theta + B\cos{\theta}e^{i\delta} \end{bmatrix}$$ I decided to convert the exponential...
7. ### Does a material change the direction of polarization of light?

The polarization referes to the direction of the electric field of a light wave which is to be one direction. The unpolarized light interacts with a material in various ways such as reflection, scattering, refraction. and each of which can transform an unpolarized light into a vertically or...
8. ### Polarization of elliptical fiber modes

If I have three modes in an optical fiber with elliptical facet as shown in the figure, what would be the polarization direction of the modes... what I know that it is linear polarization and could have several configuration.. but what I want really to know that if could be a situation where the...
9. ### Polarization of light -- Determine the thickness of the crystal

I don't even know where to start with this problem. What kind of slit makes linearly polarized light circularly polarized? The correct answer is d = lambda/(4(n1 - n2)) = 856nm. But how do I get there? Thanks in beforehand!
10. ### I Entanglement setup that shouldn't allow for the transmission of info

Suppose we produce a polarisation-entangled photon pair ##A_1## and ##A_2##. Then we entangle another pair ##B_1## and ##B_2##. Now suppose that these photons will not interact with anything, sending ##A_1## and ##B_1## to Alice and ##A_2## and ##B_2## to Bob. Alice measures the polarisations...
11. ### I Mach-Zender-Interferometer with polarizers

I have a question on how exactly polarizing filters would influence interference in a Mach-Zehnder interferometer. To explain, I'll show some configurations and what I would expect to happen - please tell me if I am incorrect anywhere. Here is the standard MZI configuration with no filters and...
12. ### Trying to Understand the Polarization of light

I want to understand the concept of polarization of light. I would like someone to clarify how I am thinking about it: If light is a transverse wave and it is basically an electric field(E) and magnetic field(B) each oscillating in different directions (axes) which are perpendicular to each...
13. ### Things to talk about in a Polarization Write-up

Homework Statement I am doing an assignment on Polarization of light. I have conducted experiments to prove that reflected light is at least partially plane-polarized, and to prove that Malus' Law is true. Both my experiments have given good results. I now need to find enough stuff to write...
14. ### Destructive interference in Unpolarised light

Destructive interference is excellently demonstrated in Young's double slit experiment, where dark regions are formed due the waves being out of phase. However, what really confuses me is that unpolarised light has intensity. Assuming we had perfectly unpolarised light, as in where the...
15. ### I Double slit with a quarter wave polarizer on one slit

Suppose a linear polarized light wave front is incident on a double slit. What happens if one places a quarter-wave polarizer in front of only one slit in the double slit experiment? Does one obtain the usual inteference fringes? Or the diffraction pattern only? Else?
16. ### Reversing the Faraday effect to get an induced current

Hi all! I was thinking if it is possible to revert the Faraday effect. If I have a magnetic field, it interacts with EM wave (light) by changing its polarisation. Can I got a variable magnetic field interacting with polarised light so that I can get induced current in a coil? I can understand...
17. ### Cause of polarisation due to reflection?

Quoting Resnick and Halliday's Fundamentals of Physics (page 912) on polarization by reflection: It is also known that when light is incident at the interface at a particular angle θb, the Brewster angle, the reflected light is completely plane polarized. Why does light get polarized when it...
18. ### Formal term for cross-polarization effect

Hi everyone, A friend of mine attending university in Japan is trying to write a paper in English discussing the effect that occurs when looking at a screen through polarized sun glasses (i.e. it looks dark or black). She is looking for a formal term that specifically addresses the screen...
19. ### Calculating permittivity in a constant field

Homework Statement Having a conducting sphere with radius ##R## and charge ##Q##, dielectric is put on it so that a spherical shell with inner radius ##R## and outer radius ##3R## is formed. Calculate: 1. Electric permitivitty ##\epsilon## such that ##E(r), R<r<3R## is constant and there's...
20. ### Photon absorbtion and conservation

If a (polarized) photon is absorbed by a polarization filter, does its energy go into the filter? I am wondering if that is the case to obey conservation laws. And if it passes, is its original polarisation direction somehow conserved?
21. ### 2 Polarizers attenuating a light beam

Homework Statement An angle is given between 2 polarizer's (45 degrees), through them light passes (unpolarized than after passing through the first one it polarizes), some of the light its shown on the display. For how much does the angle needs to be increased for the intensity of light to be...
22. ### How to find the orientation of polarization of a polarizer

If you have a new linear polarizer, how do you find its orientation of polarization? In other words, how do you orient it so it would, let say, polarize light vertically if there is no marking for the 0 degrees angle?
23. ### Tilted Polarizer

https://www.dropbox.com/s/t5lv4nlunn35ok8/phy1.PNG?dl=0 https://www.dropbox.com/s/ktc9pj7qmqhejrv/phy2.PNG?dl=0 https://www.dropbox.com/s/qbjz1p1gokvsgj2/Capture3.PNG?dl=0 I googled "polarizer film diagram" and "malu's law" and "polarizer physics" to obtain the pictures in this thread. I...
24. ### Quantum polarisation probability

Homework Statement I am stuck on the second paragraph but I thought I would add the first paragraph in case some context would help! Homework Equations |A> = cos(theta)|H> + sin(theta)|V> The Attempt at a Solution I am not wholly comfortable with bra-ket notation with the outer product p =...
25. ### Brewster's law for incident vertically polarised light

Brewster's law on polarisation states that if a unpolarised light is incident at a certain angle of incidence, then part of it gets plane polarised and is reflected. What happens if the incident light itself is vertically polarised for the same brewster's angle and same wavelength of light used...
26. ### How to determine the range of sensitivity for a camera sensor?

I am not sure if this is the best place to ask and I will change locations if need be, but I need some guidance on how to choose a proper sensor for my project. I am currently working as part of a team on a polarimetric camera for ocean imaging. The basic premise is that images, from above the...
27. ### I Quarter-wave plates and Half-wave plates

Hi, I am aware that quater-wave plates create a phase shifts of λ / 4 between the fast and slow transmission axis. My question is what happens if we place two quater-wave plates in series so that there is 0 degrees between the fast transmission axis and how would result change if they where...
28. ### I Polarisation entanglement

If we don't know the polarisation state of a photon before detection is it reasonable to assume that it's in a superposition of all possible states? Thank you if anyone can clarify.
29. ### Polarization components

I have a vector that represents the electric field at a specific point. How to find the vertical and horizontal polarization components of this vector?
30. ### Interpretation of polarisation experiment

Consider a fully entangled pair of polarized photons, A and B, fired at two detectors with polarisation filters in front of them. I have to get a little philosophical to understand the way the interpretations of this experiment play out. My knowledge is still very basic but I'm working on it...
31. ### B Measurement and the creation/loss of information

If we measure, say, the polarisation of a photon, the polarisation state of the photon collapses along the eigenvector of the observable corresponding to the measurement. This may seem as a loss of information of the original polarisation (for it is now collapsed into another value). However...
32. ### B Entanglement, correlation and randomness

I was wondering. In this example I use polarized photons, but maybe it is applicable to electrons and spin also. We can prepare two completely unentangled polarized photons, and send them in opposite directions to two detectors preceded by a filter at particular angles. Both of them will show a...
33. ### Does a polarisationfilter do a measurement?

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?
34. ### Probability of entangled photons passing filter independent?

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...
35. ### Are photons passing a polarization filter randomly?

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...
36. ### Can a rotating dielectric disc be polarized?

Can a rotating dielectric disc be polarized? No external electric or magnetic field .
37. ### Bell-state entanglement swapping and retrocausality

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...
38. ### A way to plastically flip a circular 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...
39. ### Why is unpolarized light halved in intensity when polarized?

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...
40. ### Do observables for polarizers at different angles commute?

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 $$\left\langle\alpha | \beta\right\rangle=\cos(\alpha)\cos(\beta)+\sin(\alpha)\sin(\beta)=\cos(\alpha-\beta)$$...
41. ### Polarisation destroying interference pattern for double slit

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...
42. ### Field inside spherical hole inside dielectric

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...
43. ### Is polarised light a result of destructive interference?

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...