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Questions tagged [huygens-principle]

Also known as the Huygens-Fresnel principle, this is a method of analysis used in problems of wave propagation in far-field and near-field diffraction. Use the diffraction tag for general diffraction questions.

When to use

This tag can be used with the tag though do not add the tag automatically with it.

Introduction to topic

Prerequisites to study

  • Calculus
  • Classical understanding of optics/light
  • Waves and how they work
  • Diffraction

Resources

166 questions
52
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10 answers

Why exactly does diffraction occur?

Why do waves that were traveling in a straight direction change direction when passing through an opening? I thought that the waves (red arrow) when colliding with the wall bounce in the opposite direction (green arrow). And the waves that pass…
jony alton
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47
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4 answers

Why is Huygens' principle only valid in an odd number of spatial dimensions?

Apparently Huygens' principle is only valid in an odd number of spatial dimensions: https://mathoverflow.net/a/5396/21349 Huygen's principle in curved spacetimes Why is this? [EDIT] This is somewhat perplexing, since AFAIK it's pretty common to…
user4552
29
votes
5 answers

How can a point source emit spherical EM waves when they are forbidden by Maxwell's equations?

I know that there exist plane wave solutions to the Maxwell equations in free space, and I tried solving them for a spherical wave emanating from a point but could find no solution consistent with the 4 equations. This seems to indicate that…
Thanos
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24
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3 answers

Can light emit light?

How and why does the Huygens principle really work? I mean, does it always work? The Huygens principle: Every point on a wave-front may be considered a source of secondary spherical wavelets which spread out in the forward direction at the speed of…
Paul
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19
votes
6 answers

How does Huygens Principle incorporate the unidirectional property of a traveling wave?

I was reading French's Vibrations & Waves where he discusses Huygens-Frensel Principle. The principle talks about how secondary sources give rise to secondary wavelets to form the displaced wavefront. However, any secondary source can form two…
user36790
15
votes
8 answers

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 slit? Huygens principle gives all the math behind…
rahulgarg12342
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14
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1 answer

Huygens wave theory not applicable to lasers or parallel beams of light?

According to Huygens wave theory, every point on a wavefront acts as a secondary source of waves. Using this principle we can never have pretty narrow parallel beams of light right? Like lasers? There will always be "leakage"(wrong terminology?) of…
udiboy1209
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12
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3 answers

Can the Huygens principle be justified rigorously mathematically?

Can the Huygens principle be justified rigorously mathematically? To what extent and what purpose is it still relevant today? Is it made obsolete by the Maxwell equations? If not, do the Maxwell equations justify it?
pie
  • 615
12
votes
2 answers

What is the basis of Huygens principle?

When we were studying mechanical waves like sound waves, and waves on strings in class, we never studied Huygens' principle with these - and nor did we really derive the laws of reflection or refraction with them. We always in any case took them to…
Charles
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11
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3 answers

Can Schrödinger Equation be derived from Huygens' Principle?

Notes of Enrico Fermi start from an analogy between mechanics and optics and with 4 pages he derives the Schrödinger equation. In all my courses, I have seen as an axiom - this is how wave-particles behave. Here it is being derived from Fermat's…
john mangual
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10
votes
1 answer

How is the quantum propagator related with Huygens principle?

Usually in quantum mechanics the wave function can be propagated via the so-called Kernel or Amplitude: $\Psi(x,t) = \int K(x,t;x',t')\Psi(x',t')dx'$. I have read in some paper that this comes from Huygen's principle, and it makes somehow sense,…
Aesku
  • 391
10
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0 answers

Double slit - higher dimensions

The double slit experiment is a real-life manifestation of the Huygens principle. As is well-known, this principle depends on whether the number of dimensions is ever or odd; as Evans1 puts it, Observe, in contrast to formula $(31)$, that to…
AccidentalFourierTransform
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9
votes
4 answers

How does the Huygens–Fresnel principle apply to diffraction?

I'm currently trying to understand the mechanics behind diffraction and gain a better understanding of the Huygens–Fresnel principle, but I've reached a hurdle that is making me question my understanding of refraction. Firstly, a quick explanation…
navnav
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9
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1 answer

Question on wave interference?

When dealing with double slit interference or interference of waves from numerous slits, the equation $nλ = d \sin θ$. However I do not understand why for calculating the angle for maxima and minima it is okay to consider the path difference of…
Nav Hari
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9
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2 answers

Huygens' Principle and Ocean Waves

Ocean waves can travel in any direction, but waves breaking on the sea-shore are usually approximately parallel to the line of the beach. How can Huygens' principle explain this phenomenon? Does it have something to do with the fact that the…
Rebecca Murray
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