The polarization tag has no wiki summary.
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1k views
Why can't my eye see itself in the mirror through polarizing 3D-glasses?
I found a pair of polarizing "3D glasses" lying around, and tried to look at myself in the mirror while wearing them.
To my utter confusion, when closing the left eye and only looking through the ...
10
votes
2answers
3k views
How do Optically Active Compounds Rotate Plane Polarized Light?
I am not sure if this is more of a Chemistry or a Physics question, but in my Organic Chem class we discussed that chiral molecules will rotate plane polarized light. However, my professor did not ...
9
votes
4answers
404 views
Why is the $S_{z} =0$ state forbidden for photons?
If photons are spin-1 bosons, then doesn't quantum mechanics imply that the allowed values for the z-component of spin (in units of $\hbar$) are -1, 0, and 1?
Why then in practice do we only use the ...
9
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4answers
711 views
What ways are there to measure the local polarization of a laser beam?
Measuring the polarization of a laser beam is a simple enough task if the polarization is the same everywhere. You can even buy commercial polarimeters.
How do you go about it if the light beam has ...
9
votes
4answers
785 views
What causes polarised materials to change colour under stress?
Our physics teacher showed the class a really interesting demonstration. He used two polarised filters in opposite orientations, then he took some antistatic tape and stretched it under the two ...
9
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2answers
330 views
Circular polarization of variable-frequency light by 3D cinema glasses
A dominant method to obtain 3D images in the cinemas seems to be circular polarization. Separate pictures are projected with (alternating) circular polarization filters and passive glasses of the ...
9
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1answer
100 views
If light is linearly polarized, does it have some spatial extent?
If light (a photon) is linearly polarized, say vertically, does it have some vertical spatial extent (perhaps in amplitude)?
8
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5answers
653 views
Will freely rotatable polarizers align?
Will two freely rotatable linear polarizers (placed in sequence and at some angular offset less than, say, 45 degrees) eventually align if you shine (plenty of) unpolarized light at the first one?
If ...
7
votes
5answers
489 views
Why Does Light Not Become Polarized In A Magnetic and/or Electric Field?
I am familiar with the Faraday Effect, but I remain confused as to why the electric and/or magnetic components of light do not naturally align themselves with a magnetic or electric field (in a ...
7
votes
1answer
143 views
Strange light polarization effect?
I spent a while working with MgF2-windowed xenon flash / discharge lamps. Primarily, I characterized their spectra with two normal-incidence spectrometers against a calibrated Deuterium lamp. In this ...
6
votes
1answer
299 views
Where does the energy go, when light is blocked by polarisation
I've been looking around about LCD monitors, and how they polarise light. When a pixel needs to be black, the light is "twisted" so that it can't go through the polarising sheet in front.
What happens ...
6
votes
2answers
717 views
Wheeler-Feynman theory, QED without fields, vacuum polarization
Initially Wheeler and Feynman postulated that, the electromagnetic field is just a set of bookkeeping variables required in a Hamiltonian description. This is very neat because makes the point of ...
5
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2answers
655 views
Why does it seem like a broken magnet's poles flip?
I just took a rare earth magnet out of an old hard drive. Lacking an appropriate screwdriver, force was used, and the magnet broke into two pieces; one about a quarter of the original size and one ...
5
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3answers
510 views
How can we describe the polarization (of light) coming from an arbitrary angle?
In an optics lab, where all optical beams pretty much reside in a plane, it is fairly simple to describe (linear) polarizations as vertical or horizontal (or s and p).
When we start talking about ...
5
votes
1answer
446 views
Polarization and mirrors
When a light beam reaches a dielectric surface, the incident and reflected beams have different intensities depending on polarization. For the so-called Brewster's angle, the reflected light is ...
5
votes
1answer
150 views
3D movie glasses making white light look red and blue
While waiting for a 3D movie to start, I was playing with the glasses they give you. I understand each lens has different polarized filters, so the left and right superimposed images on the screen go ...
5
votes
1answer
333 views
Inflation Scale via CMB Polarization
COBE, WMAP, and now PLANCK, have or are in the process of measuring anisotropies in the cosmic microwave background. WMAP has dectected E-mode polarization from electron Thomson scattering, but not ...
5
votes
1answer
171 views
Are two polarization states of light coherent?
Let's consider a situation: we have distant point source of unpolarized light in certain non-zero range of wavelengths (it's polychromatic). Let's divide this light into 2 beams depending on ...
5
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0answers
153 views
What is the difference between the properties of Electron spin and Photon polarization/helicity?
What is the difference between a photon's polarization/helicity and an electrons spin half? I know that the photon is spin 1 but isn't its polarization analogous to spin half?
This question stems ...
4
votes
3answers
161 views
How many photons does it take to measure a linear polarization?
A star emits perfectly (100%) linearly polarized light at an arbitrary angle.
How many photons must you detect to measure this angle to a precision of n binary digits? (with greater than 50% ...
4
votes
2answers
482 views
Half wave plate and angular momentum
Given:
A half wave plate freely floating in space.
Circularly polarized light, falling perpendicularly to it.
The plate changes polarisation of the beam to the opposite one. Therefore it ...
4
votes
3answers
141 views
Polarization true or false: Repeating circular filters is different from repeating linear filters?
Begin with standard abbreviations for polarized filters:
H = Horizontal, V= Vertical, D = Diagonal, R = Right circular.
HHH means three horizontal filters in a row.
Start with totally unpolarized ...
4
votes
2answers
206 views
Jones vector and matrices
With Jones vectors and matrices one can describe the change in polarization of a EM wave. What is the convention of the reference coordinate system; Is it fixed or does it change whenever the ...
4
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1answer
59 views
Spatial and polarizing beam splitters in a graphical calculus
Suppose I have four wires, and I tensor product them together
$A \otimes B \otimes C \otimes D$
I pass $A \otimes B$ through a spatial beam splitter
$Spl: A \otimes B \rightarrow A^\prime \otimes ...
4
votes
2answers
149 views
Is it possible to split a single light beam into two beams of opposite circular polarization?
A properly oriented calcite crystal will separate an unpolarized beam into two beams, one vertically polarized and one horizontally polarized. Other polarizers pass just one polarization and absorb ...
4
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1answer
146 views
Filter out polarized light
Unpolarized light enters the polarizer and gets polarized at one certain angle. If we place an analyzer behind the polarizer and align them, we observe that all light is transmitted. If we rotate the ...
3
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2answers
219 views
Why does the electric field dominate in light?
I read a book on the wave property of light where the author mentioned that the electric field, instead of magnetic field, dominates the light property. I don't understand why.
In Maxwell's theory, a ...
3
votes
2answers
841 views
What is the effect of polarization on diffraction by a narrow slit?
Consider the well known demonstration of diffraction by a narrowing slit.
(See for example the demonstration at the 30 minute mark of this lecture at MIT by Walter Lewin)
It is my (possibly mistaken) ...
3
votes
1answer
68 views
Three polarizers, 45° apart
If light is passed through two polarizing filters before arriving at a target, and both of the filters are oriented at 90° to each other, then no light will be received at the target. If a third ...
3
votes
1answer
251 views
Polarization rotation: Jones Matrix that maps Horizontal to right circular
I am looking at the Poincaré sphere and I am trying to compute a Jones matrix for a particular rotation. Specifically, I would like it to perform the following maps:
$O :|H \rangle \rightarrow |R ...
3
votes
1answer
118 views
Reflected optical rotation of polarised light
Assume polarised light travels through an optically active medium (e.g. water with lots of sugar) with the specific angle $\alpha_s$ of depth $d$ at which end it is reflected (so in total it travels ...
3
votes
2answers
115 views
What is a photon's speed inside a dieletric?
We know that EM waves are slowed down in a dielectric. But at what speed does the photons that make up the wave travel?
Do they always travel at the speed $c$, but colliding/being absorbed and ...
3
votes
1answer
77 views
Monochromatic wave
If we have an EM wave like this one:
$$E=\begin{pmatrix}1\\i\\0\end{pmatrix}e^{-i(\omega t-kz)}$$
The wave has clearly only one frequency $\omega$, but is it monochromatic? My doubt is that it's ...
3
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2answers
92 views
Liquid crystal polarizes light reflection question
I was hoping someone could help me with understanding why a row of polarizes reflects a light wave when the whole row is the same length as the wavelength of the light.
I pretty much get the ...
2
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3answers
294 views
Partially polarized light in laboratory
Does anybody know a way to create (in laboratory, but with no super-sophisticated equipement) a beam of light with partial linear polarization whose degree of polarization can be adjusted (at least ...
2
votes
1answer
210 views
Electromagnetic field of unpolarized light
I need help in finding an expression for the instantaneous electric and magnetic field of unpolarized light in order to write down and evaluate the time-averaged norm of the Poynting vector (i.e. the ...
2
votes
1answer
337 views
Why do polarized sunglasses remove (most) reflections on car windows?
Why do polarized sunglasses remove (most) reflections on car windows? I know that both lenses of polarized sunglasses are polarized in the same direction and I can see that reflections in my own ...
2
votes
1answer
432 views
What are the polarization states of the photons in a polarized and unpolarized light?
The photons are completely polarized, i.e their polarization states can be expressed as $a|R\rangle+b|L\rangle$, where $|R\rangle$ and $|L\rangle$ are two helicity eigenstates of the photon. For ...
2
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1answer
104 views
How would one generate Brownian light? What would it look like?
When light is an equal mix of all visible frequencies, we call it white light.
By analogy, sound that is a mix of all audible frequencies is called white noise.
For sound, there is an additional ...
2
votes
1answer
332 views
What are the properties of the partially polarized light on refraction?
When a ray of ordinary light is passed on the surface of the water the reflected light will be completely polarized( vibrations in one plane).
My question is what will be plane of vibration in the ...
2
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2answers
165 views
Intrigued about a polarizer effect
This comes from one of my physics course at university (many years ago!), I hope I recall it right.
We were studying optics, and were given some polarizer filters to experiment. They were disc- ...
2
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1answer
80 views
Is the spin state of an atom related to the polarization of the photon it spontaneously emits?
From literature I've been reading, I find that scientists are able to "map" atomic states onto photon states. Are they talking about spin states and corresponding photon polarization states? Can ...
2
votes
1answer
286 views
How to compute the intensity of a polarized wave going through a polaroid?
If an electromagnetic wave is linearly polarized, the intensity of the light that goes through a polaroid is proportional to the square of the cosine of the angle between the polarization plane and ...
2
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0answers
209 views
How does one calculate the quantum propagator for a massless photon
So I want to calculate the quantum massless photon propagator. To do this, I write
$$
A_\mu(x) = \sum\limits_{i=1}^2 \int \frac{d^3p}{(2\pi)^3} \frac{1}{\sqrt{2\omega_p}} \left( \epsilon_\mu^i (p) ...
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0answers
75 views
Magnetic Fields
If running a current through a magnet can reverse the magnetic field, then how strong does the current have to be and how would it best be run through the magnet.
2
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1answer
124 views
about polarization of light
In the course of circuits and electronics, I remember there is an experiment to show the polarization of the wave as lissajous figures. I am wondering for polarized laser, is there any way to ...
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5answers
3k views
1
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2answers
327 views
Laplace's equation
I have got some mathematical difficulties in the following exercise :
Calculate the potential of the polarized sphere along the z-axis. There are no free charges.
For this, we need to solve ...
1
vote
2answers
40 views
Polarization of Light
How do materials polarize light? I know that they polarize light in the same plane, but light has two perpendicular directions with the two fiels, so which direction is reflected and why?
And if ...
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2answers
110 views
Doubts concerning Wigner's classification
Wigner classified particles in function of the eigenvalues of $P_\mu P^\mu$ and $W_\mu W^\mu$. Then, it can be proved that for massless particles spin values can be only $\pm s_{max}$. But for a ...
