All Questions
Tagged with optics diffraction
68
questions
511
votes
6
answers
81k
views
How does light bend around my finger tip?
When I close one eye and put the tip of my finger near my open eye, it seems as if the light from the background image bends around my finger slightly, warping the image near the edges of my blurry ...
- 4,869
35
votes
7
answers
253k
views
What is the difference between diffraction and interference of light?
I know these two phenomena but I want to know a little deep explanation. What type of fringes are obtained in these phenomena?
24
votes
3
answers
20k
views
Squinting at street lights
Simple question, I've always wanted to know the answer to this.
Why do you see a pair of lines radiating out from street lights when you squint at them? I can't think of a better way to describe what ...
user5335
6
votes
1
answer
6k
views
Diffraction Pattern on LCD Screen
I was up late working with my red LED headlamp on and when I was looking at the black part of my LCD (Apple Retina Macbook Pro) screen I noticed this interesting diffraction pattern. I'm confused ...
- 163
4
votes
1
answer
373
views
Interpretation Fourier Diffraction
I got familiar with interference and now want to understand it with the help of Fourier optics, as it is called.
For the derivation of the diffraction integral the following setup is to consider:
...
- 462
5
votes
4
answers
795
views
Possibility of making an experiment in a classroom to simulate DNA diffraction
I am a TA in a structural chemistry class. The professor want me to show students how Watson and Crick determined the structure of DNA from X-ray diffraction results of DNA crystals. The professor ...
33
votes
3
answers
3k
views
How is momentum conserved in diffraction?
Sigh. Approaching retirement age and still deeply confused about something I first encountered in highschool 40 years ago.
Consider the usual double slit experiment. Make the light source be a laser ...
- 1,145
6
votes
3
answers
9k
views
Why is it difficult to differentiate between interference and diffraction?
Why is it difficult to differentiate between interference and diffraction? Is it because we don't clearly understand how both of these phenomenon takes place?
My thoughts: From an answer to one of ...
- 3,905
4
votes
2
answers
12k
views
Intensity of subsidary maxima in a diffraction grating pattern?
I was wondering if anyone knew what the intensity of subsidary maxima was?
My intuition would tell me that it would be the square of the amplitude of the wave illuminating the slits (I am thinking ...
- 3,997
1
vote
3
answers
9k
views
Where does the 1.22 come from in Rayleigh criterion for circular apertures?
For the formula 1.22, $\lambda/b$, which describes the angle at which resolution occurs, where does the 1.22 come from? I have looked at the derivation and there doesn't seem to be any explanation?
- 124
31
votes
3
answers
10k
views
Why does light reflected from an LED TV screen make a sharp X pattern?
If you shine a laser pointer or generally any coherent light at the screen of a fancy, new TV, you get a very sharp X pattern.
I think this is a property of LED screens specifically. This phenomenon ...
- 103k
21
votes
2
answers
5k
views
Amateur moon laser ranging
Questions first, then my rough estimations:
Is it possible to perform moon laser ranging with amateur motorized 114 mm telescope? My calculations suggest that for 1 mJ laser it should receive ~2 ...
- 2,424
18
votes
2
answers
12k
views
Why do we see a rainbow of colors reflected off a CD or DVD?
So, we all know if you shine some light on CD (compact disc) or DVD, you can see all the colors from red to violet.
What is bothering me is what is the reason of why do we see the colors on compact ...
- 327
14
votes
8
answers
13k
views
Why does a wave actually diffract?
I know that waves diffract around a slit and this is due to the Huygens-Fresnel principle. But I never understand this in an intuitive wave that why does a wave become a spherical wave front at the ...
- 2,479
13
votes
2
answers
495
views
Why do diffractions spikes from small aperture not have fringes?
Small aperture in a photo camera leads to well-known starburst effect:
(source)
It's generally believed to be caused by diffraction.
But since diffraction is a wavelength-dependent phenomenon, it ...
- 29.1k