All Questions
Tagged with refraction optics
916
questions
18
votes
7
answers
26k
views
Why does light change direction when it travels through glass?
This was explained to me many years ago, by a physics teacher, with the following analogy:
"If someone on the beach wants to reach someone else that is in the water, they will try to travel as much ...
- 281
2
votes
0
answers
185
views
Modeling a spray painted polyurethane surface reflection
I'm modeling light interaction/reflection from a fiberglass surface with polyurethane epoxy (that is very reflective) that has been spray painted with a matte black paint. I'm looking for some input -...
- 283
1
vote
1
answer
918
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Does coverslip thickness matter for high NA oil immersion objectives?
This question is related to Impact of covering glass on lens performance.
I use a 63x TIRF objective with a numerical aperture of 1.46 and oil immersion.
The immersion oil has an index of $n_e=1.518$....
- 951
89
votes
9
answers
15k
views
What really causes light/photons to appear slower in media?
I know that if we solve the Maxwell equation, we will end up with the phase velocity of light being related to the permeability and the permittivity of the material. But this is not what I'm ...
- 2,452
5
votes
3
answers
16k
views
intensifying a light source
When trying to intensify a beam of light by refracting it through a lens, (as in a lighthouse fresnel system or similar railroad style switch lamp from years past), is the beam intensity increased by ...
- 51
26
votes
5
answers
176k
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Why does the road look like it's wet on hot days?
Often, I'll be driving down the road on a summer day, and as I look ahead toward the horizon, I notice that the road looks like there's a puddle of water on it, or that it was somehow wet. Of course, ...
- 3,439
2
votes
1
answer
1k
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Refractive index of organic solvents in near-infrared
I wonder if the refractive index of acetone, ethanol, methanol, heptane was measured in the range above 830 nm. The site refractiveindex.info provides it only for visible, and I couldn't find any ...
- 695
15
votes
3
answers
2k
views
Can the speed of light become complex inside a metamaterial?
The speed of light in a material is defined as $c = \frac{1}{\sqrt{\epsilon \mu}}$. There are metamaterials with negative permittivity $\epsilon < 0$ and permeability $\mu < 0$ at the same time. ...
- 9,910
12
votes
3
answers
40k
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Refractive Index of Air Depending on Temperature
How does the refractive index of air rely on the temperature? Is there a theoretical derivation of it?
- 2,125
2
votes
3
answers
2k
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Reconciling refraction with particle theory and wave theory
I have searched the web for good answers to why refraction occurs when light moves from one medium to another with different density. I have limited background in physics and want to know if there is ...
- 151
27
votes
5
answers
16k
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Eyes open under water
Yesterday I looked underwater with my eyes open (and no goggles) and I realized I can't see anything clearly. Everything looks very, very blurry. My guess is that the eye needs direct contact with air ...
- 3,930
44
votes
4
answers
277k
views
Virtual vs Real image
I'm doing magnification and lens in class currently, and I really don't get why virtual and real images are called what they are.
A virtual image occurs the object is less than the focal length of ...
- 6,927
50
votes
3
answers
12k
views
How are classical optics phenomena explained in QED (Snell's law)?
How is the following classical optics phenomenon explained in quantum electrodynamics?
Reflection and Refraction
Are they simply due to photons being absorbed and re-emitted? How do we get to Snell'...
- 13.5k
2
votes
1
answer
359
views
Reflected and refracted wave sphased
When we derive refraction and reflection laws for a generical plane wave on a surface, we say that reflected and refracted must be in phase with the incident wave. Why a medium cannot do a sphased ...
- 1,434
24
votes
1
answer
27k
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How does a photon travel through glass?
This was discussed in an answer to a related question but I think that it deserves a separate and, hopefully, more clear answer.
Consider a single photon ($\lambda$=532 nm) traveling through a plate ...
- 4,700