The tag has no wiki summary.

learn more… | top users | synonyms

2
votes
1answer
1k views

Application of diffraction problem!

Here is a problem that I am working on, which is the applying the concepts of diffraction to the setting of the sun: Air has a small, usually negligible index of refraction. It is 1.0002926. This ...
3
votes
1answer
145 views

How small can diffraction grating be?

Like in title, how small can diffraction grating be? And, of course be "fully operational". I mean, littles diffraction grating possible that still works as full-sized one.
7
votes
1answer
547 views

Calculating diffraction patterns using FFT

I'm trying to write a piece of code that calculates a diffraction pattern similar to an X-ray experiment using a FFT. From my knowledge, the diffraction pattern for point particles can be calculated ...
3
votes
2answers
137 views

X-ray diffraction from crystals and time-averaging

To calculate the elastically scattered intensity of x-rays from crystals, one classically considers scattering from a free electron first and then one sums up the scattered em-fields of all electrons ...
0
votes
1answer
120 views

Does diffraction contribute to the Black Drop effect?

Two reasons are given to explain the black drop effect here, but I think I came up with a third. Consider a two-dimensional cross section of the situation just after second contact and just before ...
5
votes
1answer
525 views

How can the Huygens-Fresnel principle be derived from the Maxwell equations?

The Huygens-Fresnel principle states that every point to which a luminous disturbance reaches becomes a source of a spherical wave. I have been trying to understand this considering a infinite screen ...
0
votes
1answer
176 views

Raileigh diffraction by circular aperture

I am a beginner to physics and would need an explaination on a statement in a book "Karttunen, Fundamental astronomy". In a section named "Raileigh diffraction by circular aperture", author states: ...
4
votes
2answers
309 views

Effect of a wavefront deformation on the far-field diffraction pattern of a TEM00

By performing Matlab simulations on a TEM00 mode (approximated by a gaussian intensity profile with a flat wavefront), I got the impression that applying wavefront deformations (such as a single ...
3
votes
1answer
76 views

Describing quantum intereference with only currents and densities

I know about and believe to understand the general wave equation based Kirchhoff diffraction formula, which in the Fraunhofer limit leads to a farfield complex wave function by Fourier transforming ...
2
votes
1answer
339 views

What's the mathematical background to the representation for Gaussian beams?

Background A general optical system (not necessarily having an axis of rotational symmetry) can be represented, for small deviations from a base ray, by the matrix transfer equation, $$ ...
0
votes
1answer
106 views

Describing the surface of a sphere in Huygens' Principle

$U(P) = \frac {iU(r_0)}{\lambda} \int_{S} \frac {e^{iks}}{s} K(\chi)\,dS$ Where $S$ describes the surface of the sphere, how is the surface of the sphere described? Sorry if you feel this is quite a ...
4
votes
2answers
160 views

What are the lines visible between two cards held edge-to-edge?

Hold two cards (say credit cards) edge to edge, anything from a very slight touch to about 1/3 mm separation, in front of any ordinary light source. When I do this I see several fine dark parallel ...
3
votes
1answer
446 views

Calculating Fraunhofer diffraction patterns

How does one calculate the Fraunhofer diffraction pattern for the following arrangement of slits: |...|...........|...| ..a.....3a......a (Four slits arranged linearly, spaced a distance a, 3a and ...
0
votes
1answer
970 views

reflection, refraction and diffraction occur in radio waves, which one occurs the most?

One of the things about Radio waves is that they undergo different behaviors such as reflection, refraction and diffraction when in contact with obstacles such as walls, buildings etc. what i want to ...
3
votes
1answer
334 views

Why is the diffraction pattern for an annular aperture the difference of the two Bessel functions?

Inspired by this question, the pattern for the annular intensity is given by the square of the difference of the two Bessel functions. I would have thought the sum was more appropriate, could someone ...
3
votes
2answers
160 views

The Bahtinov focusing mask

I'm looking for a webpage or a book or reference that might give me a better (and hopefully more scientific) understanding of how the Bahtinov mask works (which I understand to be the same as ...