All Questions
36
questions
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47
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Why are Fresnel coefficients not symmetric?
When talking about reflection, we have the following coefficients for the electric field:
$$r_{\perp}=\frac{n_1\cos(i)-n_2\cos(t)}{n_1\cos(i)+n_2\cos(t)} \\ r_{\parallel}=\frac{n_2\cos(i)-n_1\cos(t)}{...
- 267
1
vote
2
answers
72
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Why total reflection happens at only 1 angle?
The critical angle can be intuitively understood by Snell's law.If the incident medium has a bigger diffraction index than the refracted medium then according to Snell's law the refracted ray will be ...
- 101
1
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2
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236
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What happens to the electric field of circularly polarized light upon a normal reflection from a mirror?
Let's imagine we have Right Circularly Polarized Light propagating in the $+\hat{z}$ direction toward a perfectly reflecting mirror. Before reflection, the light has the electric field:
$$\vec{E}(z)=...
- 141
0
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1
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28
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Fresnel coefficients with permanent magnetism
I am familiar with the standard derivation of the Fresnel coefficients for linear magneto-dielectrics (for instance https://en.wikipedia.org/wiki/Fresnel_equations#Derivation). However, I was ...
- 352
1
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0
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65
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What are the physics behinde reflection and refraction of electromagnetic wave at a dialectric surface?
I have understood the most of the equations that lead to the Fresnel-Equations from electromagnetic waves and Maxwell equations. But not enough to understand what is happening. So I don't ask for an ...
- 11
0
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0
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27
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Electrodynamics- Could a strong negative charge near a mirror push away valence electrons and render it non-reflective?
My understanding of electromagnetism would have me believe that since it is the waveform of the photon interacting with the conglomerate waveform of the "ocean" of electrons saturating a ...
1
vote
1
answer
138
views
Can total internal reflection (TIR) occur in metals?
Is it possible to get Total Internal Reflection (TIR) when a light beam hits a metallic surface of complex index $\tilde{n}=n_r+n_ii$? If not, is there a way where a light beam can hit a metallic ...
- 225
2
votes
1
answer
65
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Analysis of the reflection in metal
In order to solve the reflexion in a material with a complex index the solution I've found on textbooks is to define $\hat{n}\cos{\phi}:=a+bi$ where $\hat{n}=n_r+n_ii$ is the complex index and then ...
- 225
2
votes
1
answer
255
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Reflectance and transmittance from an anisotropic layer
I am trying to follow a derivation for the reflectance and transmittance of a plane wave from an anisotropic material ($\varepsilon_a,\varepsilon_b,\varepsilon_c$). The derivation uses a $4 \times 4$ ...
- 284
3
votes
1
answer
260
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Light on reflection at junction point
When a light (or any other EMW) is striking a reflecting surface it is expected that it would reflect back with same angle as of incidence with normal to the point. Considering wave nature of light, ...
- 75
2
votes
1
answer
91
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Physical interpretation of increasing Reflectivity with increasing $\epsilon_i$ for small $\epsilon_r$
Currently I have plot Reflectivity, $R$ of a generic material (assuming a complex dielectric function, $\epsilon = \epsilon_r + i\epsilon_i$) as a function of $\epsilon_i$ for various $\epsilon_r$ ...
- 123
6
votes
1
answer
432
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How thin can the wires of a sub-wavelength gold mesh be and still be half as reflective as a solid sheet? What physics dictates this?
A metal wire mesh can be nearly as reflective to an incident EM wave as a solid sheet of metal provided the wires are sufficiently conductive and the size of the mesh is much smaller than the incident ...
- 6,273
0
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1
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48
views
All photons incident upon an object are ultimately scattered somewhere, right? Either elastically or inelastically?
From Wikipedia:
Light has a certain probability of being scattered by a material. When photons are scattered, most of them are elastically scattered (Rayleigh scattering), such that the scattered ...
- 4,509
1
vote
1
answer
304
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After a 'reflection phase change' of a light wave, are the magnetic ($B$) and electric ($E$) fields really out of sync with each other?
Wikipedia says the Electric-field shifts by 180-degrees, but the Magnetic-field by 0-degrees.
Are there other instances where the $E$-field and $B$-field of an EM-wave are out-of-sync (out-of-phase, ...
- 4,509
2
votes
1
answer
232
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Huygens' Principle alternative explanation on reflection
It seems that I have been stuck on this one paragraph about the derivation of the law of reflection using Huygens' Principle. This is what I think I understand:
The line segment AA’ of the wavefront ...
- 43