All Questions
Tagged with optics optical-materials
13
questions
116
votes
6
answers
115k
views
Why is glass transparent?
Once I asked this question from my teacher and he replied "Because it passes light.". "And why does it pass light?" I asked and he said, "Because it is transparent.".
The same question again, Why ...
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19
votes
1
answer
2k
views
How can the refractive index be below 1 in a dielectric?
Upon checking the optical properties of different dielectrics, I found the interesting case of $Al_2O_3$. It seems to be reported with a refractive index below 1 in the infrared range of $10 - 12~\mu ...
- 4,788
20
votes
2
answers
25k
views
Why is diamond transparent while graphite is not?
Diamond and graphite are both made of the same atom, carbon. Diamond has a tetrahedron structure while graphite has a flat hexagonal structure. Why is diamond transparent while graphite is not (at ...
- 3,348
6
votes
0
answers
245
views
Are there yet Optical Magnetic Mirrors (OMMs) which reflect via interaction with the magnetic field?
update 2021: As the question has remained unanswered for five years and the field of optical metamaterials has advanced, I think this question can be revisited.
The most familiar mirror relies on ...
- 6,273
4
votes
1
answer
10k
views
Why does optical media have different refractive indices?
Optical density is a measure of the refracting power of a medium. In other words, the higher the optical density, the more the light will be refracted or slowed down as it moves through the medium. ...
- 41
3
votes
2
answers
365
views
Ideal surface for a perfect lens
in this physics lecture, on slide 15-16, it is found that the ideal surface for a perfect lens (which maps a plane wavefront into a perfect spherical wavefront, i.e. which makes focus all input ...
- 1,319
36
votes
4
answers
5k
views
Why are the edges of a broken glass almost opaque?
Unfortunately I broke my specs today which I used in this question.
But I observed that the edges are completely different then the entire part of the lens. The middle portion of the lens was ...
- 8,230
6
votes
2
answers
2k
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Why do everyday plastic items interfere with light polarizers?
I recently bought a few pieces of linearly polarized film (the one intended for smartphone LCD screens). At first I was confused because I could not make the polarizers work as they should - no matter,...
- 161
7
votes
2
answers
1k
views
Slowing down light in an opaque crystal for a whole minute
I just read about a team of physicists at the University of Darmstadt, Germany, that managed to completely slow down a beam of light that traveled through an opaque crystal (article here).
How is it ...
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5
votes
2
answers
4k
views
Why can't ultraviolet light pass through glass?
What factor determine whether a body behaves like a transparent object for EM waves of a particular frequency?
- 51
4
votes
2
answers
233
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Are there any real-world examples of refraction of light by magnetic permeability?
The question Fresnel Transmission Coefficient for Magnetic Field is interesting.
Thinking about it led me to reflect upon what little I know of the history of optics, with refraction by lenses and ...
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1
vote
1
answer
6k
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Visible light through a single-mode optical fiber?
If I understand things correctly, the optical fibers used for (long-range) data transmissions are generally single-mode fibers, transmitting light in the 1300-1500 nm spectrum.
Now, could such a ...
- 349
0
votes
1
answer
47
views
Which coefficients are needed to numerically obtain transmission spectrum?
I'm using Omnisim program. I would like to obtain transmission spectrum of certain material so I have created two polynomials: one representing real refraction coefficient and one representing ...
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