All Questions
90
questions
0
votes
2
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123
views
Diffraction when the wavefront is not parallel to the plane
I am studying Feynman's chapter on the origin of the index of the refractive index (see this link).
If I am not mistaken, what he does is to prove that when a wave enters a medium (modelled as a ...
- 507
0
votes
0
answers
46
views
How can a greater than 1 reflectance coefficient be explained in $\rm SiC$-$\rm SiO_2$ interface?
I ran a simulation using the Transfer Matrix Method to plot the R,T and A curves for a SiC->SiO2 interface. There's a region of incident energies where the |r|^2 I get is higher than 1 and the ...
- 11
0
votes
1
answer
37
views
Ray separation in waveplates
In a birefringent medium, the ordinary and extraordinary rays have different Pointing-vector directions and, therefore, different propagation directions, since the direction of the Poyting-vector ...
- 47
1
vote
0
answers
34
views
QFT view of lower light speed of light in medium [duplicate]
In classical EM theory, if we have a medium whose dielectric coefficient is independent of wavelengths (suppose we filter the incoming signal to a certain frequency band), then the waveform gets to ...
0
votes
0
answers
28
views
How does an electromagnetic wave behave when it enters a medium with refractive index less than unity?
From what I am able to find, the phase velosity of the wave exceeds c, but the group velosity remains less than c. However, why does the wave form wavepackets after entering a medium with refractive ...
- 11
1
vote
0
answers
106
views
The speed of light in medium with different frequency
We know that the speed of light in vaccuum can be expressed as $c=\frac{1}{\sqrt{\mu_0\epsilon_0}}$ and thus the speed of light in vaccuum is thus $$v=\frac{1}{\sqrt{\mu\epsilon}}=\frac{c}{\sqrt{\...
- 83
0
votes
1
answer
46
views
Help with dispersion relations for EM waves in anisotropic dielectric materials
I am really struggling to understand the following dispersion relations which we derived in class.
For an electric field in the z-direction, we have:
$$k^2_x + k^2_y = \frac{\omega^2}{c^2}n_z^2\tag{1}$...
- 155
0
votes
2
answers
66
views
How to use the boundary conditions of electromagnetic waves to derive the refraction law of light?
In my book it says we can use the boundary conditions of electromagnetic waves to derive the refraction law of light. How to derive it?
- 353
-1
votes
1
answer
60
views
Do any of the color bands in a rainbow contain an electrical charge relative to clouds that might explain a photo of lightning striking a rainbow?
Caveat: While I am not a physicist myself, I am extremely interested in physical phenomena. I am well versed in electrical theory, and I am aware of the attraction between the bottoms of clouds and ...
1
vote
0
answers
67
views
How does Dipole coupling affect macroscopic polarizability and refractive index
I have taken some measurements of refractive index (refractometer (commercial Brix meter), nD20 i.e. 20 degrees C and 589 nm) and density of sucrose/water mixtures and also of ethanol/water mixtures.
...
- 313
0
votes
0
answers
35
views
Why does a light wave travel at a different speed when the density of medium is different [duplicate]
Why does light waves travel at different speeds when the density of medium changes? Can you slow down light?
- 5
2
votes
0
answers
102
views
Why does refractive index increase with concentration of the medium?
I learnt that lights decrease velocity in a medium during absorbance and emission of its energy in the charged particles in the medium. From the Beer's law, I read that absorbance is directly ...
- 21
11
votes
1
answer
847
views
Refractive index of water
The index of refraction is given by the following formula:
$$
n = \sqrt{\frac{\epsilon \mu}{\epsilon_0 \mu_0}} = \sqrt{\epsilon_r \mu_r},$$
where $\epsilon_r$ is the relative permittivity/dielectric ...
- 665
0
votes
1
answer
89
views
What would stationary light look like? [closed]
I mean, have we ever witnessed what we understand and call as light at rest, and what would it look like at rest?
3
votes
1
answer
462
views
Brewster's angle for Metal?
As metal has a high refraction index, it is possible to have Brewster's Angle for Metal when the light incident from the air? Is it possible to derive from any formula?
- 41