All Questions
21
questions
7
votes
5
answers
14k
views
Light waves can't have a wavelength
The wave nature of light comes from Maxwell's equations. More precisely, the two wave equations that come from them:
$$\Delta\vec{E}=\mu\varepsilon \frac{\partial^2\vec{E}}{\partial t^2}\\
\Delta\vec{...
- 267
0
votes
0
answers
42
views
Why Do Harmonic Components Define Wavelength in Diffraction and Interference Phenomena?
I'm exploring the physical principles underlying diffraction and interference, specifically how these phenomena depend on the wavelength of harmonic (sinusoidal) components of a wave. My question ...
- 85
0
votes
2
answers
70
views
Why do parabolic antennas need to be the same width as their wavelength?
I am reading the wikipedia page for parabolic antennas, and have a question about the below quote:
In order to achieve narrow beamwidths, the parabolic reflector must be much larger than the ...
- 137
0
votes
1
answer
66
views
How to correctly understand wavelength of EM waves?
When we mention wavelength of EM waves, does the wavelength mean vacuum wavelength?
Is the frequency of every scalar component (x, y and z) $c/λ$, no matter whether it's linearly, elliptically or ...
- 69
4
votes
1
answer
91
views
Link between resonant states (quasinormal modes) in 1D wave equation, and roots in reflection coefficient?
For a simple Fabry-Perot cavity formed by a dielectric slab, the quasi-normal mode frequencies (i.e. $\omega=i \frac{c}{2nL}\ln{r^2}$, where $nL$ is the optical path difference between ends of the ...
- 972
0
votes
3
answers
474
views
What is the wavelength of light in a practical sense?
Okay, so I know that a wavelength is a distance of crest and a trough added together which makes a whole wave, but what is it in the real sense? Like in the case of sound I know when we say "...
-1
votes
1
answer
122
views
If ultrasonic waves have such large wavelengths, then how can they be used to sense such small details?
We use the properties of waves for sensing. This includes electromagnetic waves, such as in lasers, but also mechanical waves, such as sound. And one of the primary factors that determine how useful a ...
- 889
0
votes
1
answer
165
views
Will there be any diffraction if the gap width is smaller than the wavelength?
As the diffraction will be the largest when the wavelength is equal to the gap width, I wondered if there would be any diffraction if the gap width is smaller than the wavelength, and If there is, why ...
- 1
1
vote
3
answers
1k
views
When is diffraction most pronounced?
My notes says the following things about diffraction:
The larger the ratio of wavelength to slit (or object) width, the more pronounced the diffraction is and the more spread out the wave energy is. ...
- 372
0
votes
1
answer
44
views
What is the difference between $v=fλ$ and maximum velocity in the formula $v=ωY_{\max}$? [closed]
I was wondering what the difference is between speed in the formula $v=fλ$ and maximum velocity in the formula $v=ωY_{\max}$ as applied to a wave.
- 13
0
votes
1
answer
1k
views
What is the spacing between interference fringes?
In this problem, we are trying to determine the spacing between interference fringes for a setup of two optically flat glass plates with a small wedge of air between them.
I am attaching a screenshot ...
- 151
0
votes
1
answer
59
views
Why is refraction of light at a boundary wavelength dependent, and are the two proportional? [duplicate]
Just wondering, why is it that blue light will refract less than red light, i.e. why does the fact that blue light has a shorter wavelength mean that it will refract less at a boundary?
I read ...
- 979
1
vote
4
answers
480
views
Question about dispersion relation
I'm confused about the nonlinear dispersion relation like $\omega(k) ∝ k^2$.
Does this kind of wave have multiple frequencies?
I have always considered the linear dispersion case, $\omega(k) ∝ k$, ...
- 185
11
votes
5
answers
8k
views
Intuitive explanation for why blue light is refracted more than red light? [duplicate]
I understand the equation explaining angles of refraction related to wavelengths. But I'm looking for a more intuitive approach/visual explanation? Perhaps related to QM?
- 799
1
vote
3
answers
1k
views
Why is the next minimum $\lambda$ from central maximum in the derivation of the Rayleigh criterion for a diffraction grating?
I am struggling to understand part of the derivation for the Rayleigh criterion, which states that
"Two images are just resolvable when the center of the diffraction pattern of one is directly over ...
- 2,470