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5
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175 views

Why is this way of calculating the diffraction pattern valid?

I've seen that in some books (Fowles) the intensity of the diffraction pattern is calculated in the following way. We place the source $S$ and the point at the screen $P$ in the line perpendicular ...
3
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0answers
45 views

Beating the Diffraction Limit with NSOM

I am trying to understand exactly why we can beat the diffraction limit when using near-field scanning optical microscopy (NSOM). For those who aren't familiar with NSOM, check out this article: ...
2
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0answers
38 views

Fraunhofer Diffraction and Lenses

Suppose we have the diffraction pattern for a single slit in the Fraunhofer approximation. In order to see this diffraction patter at finite distance we locate a converging lens. Is the diffraction ...
2
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0answers
26 views

Does the Abbe limit hold for a single lens?

Let us say I have a single (converging lens) could I use the Abbe diffraction limit (for a microscope) to find its resolution or do I have to use the Rayleigh criterion. (i.e. Is the Abbe diffraction ...
2
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0answers
77 views

Diffraction grating from first principles

I have realised that a lot of books and online resources fail to give a detailed treatment of the derivation of the diffraction grating interference pattern. Normally only the result is stated. I was ...
2
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0answers
17 views

Circular diffraction onto uneven surface

I'm trying to figure out how to solve for a surface using a circular diffraction. I have a pinhole diffraction that I'm projecting into a surface and I'm trying to figure out how to derive the shape ...
2
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0answers
45 views

Airy Pattern as infinite sum of Fraunhoffer Patterns

Is there a way to view the Airy Pattern as an infinite sum of Fraunhoffer diffraction patterns? I don't know where the 1.22 would come from then. Is there something inherently wrong with collapsing ...
1
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0answers
36 views

Disadvantages of viewing a diffraction grating at larger order?

If you are using a diffraction grating as a spectrometer you are likely to use high order, because you have a better resolution (as a result of larger dispersion??). But are there any disadvantage? I ...
1
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0answers
92 views

I have negative slop of Williamson-Hall plot, XRD data. Is this right?

I have Ag (silver) powder sample. I measured xdd of the sample and got very good 2theta peak. Since I want to know bulk modulus and Young's modulus of Ag(silver), So, I got williamson-Hall plot ...
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0answers
43 views

Can I calculate the form of the aperture from the diffraction pattern?

As I understand, the Fraunhofer diffraction pattern of light is the Fourier transform of the aperture. More precisely, the amplitude of light would be the Fourier transform and the intensity its ...
1
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0answers
145 views

Can the intensity distribution behind edges and slits be explaint by the interaction with the surface electrons of the edges?

Reading about diffraction of EM radiation on edges, slits and multi slits as well as about electron diffraction behind a wire I came to the conclusion that the intensity distributions on an observers ...
1
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0answers
70 views

Rayleigh criterion for sound and parabolic microphone

Currently I am developing a parabolic microphone for a study project. I've heard and read that the maximum wavelength of sound that the given diameter microphone can focus is determined based on the ...
1
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0answers
32 views

Property of $Cu$ so that it is used as target in in X-ray diffraction (XRD)?

Why only $Cu$ is used as target element in X-ray diffraction (XRD)? Why not other elements? And which rays has high intensity $k_\alpha$ or $k_\beta$?
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180 views

Can the diffraction/interference pattern behind the slit (double slit) be calculated with Feynman path integrals (QED)?

I often see Feynman path integrals explained by a graphic which shows the slit and then the electron goes all possible ways behind the slit. Ok that is nice to understand the Feynman path integral, ...
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0answers
104 views

Intensity of Brightest Fringe of a multi-slit Diffraction

Let's say we have a multi-slit experiment with N slits.Since the central fringe has the most intensity, is there an equation to calculate the intensity of central fringe in terms of the intensity of ...
1
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0answers
51 views

Reciprocal space maps units

I have seen reciprocal space maps in different units. In some figures, it is represented in delta(l) delta(h) reciprocal space maps units. In some figures it is shown in Q(parallel) and Q(normal) ...
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0answers
32 views

Modeling the diffraction of arbitrary electric fields by diffraction gratings

I have read from many sources that the Fraunhoffer diffraction pattern is the Fourier transform of the grating. But I feel like these explanations do not take into account the curvature of the initial ...
1
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0answers
160 views

Fabry Perot Etalon - changing wavelength and plate distance

Given reflectivity $R = 0.75$, an etalon is used as an interference filter, transmitting light of wavelength $4.3\mu m$ at normal incidence. The full width half maximum is about $\Delta \lambda = 0.2 ...
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0answers
75 views

Quick question on convolution - Diffraction through a pair of slits

We know that the fourier transform of the amplitude function (in terms of $y$) gives you the amplitude function (in terms of $\theta$) Consider a pair of triangular slits: Fourier transform of ...
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0answers
48 views

Optical Spectra and the Diffraction Grating

I'm doing a lab where we are identifying different gases by their diffraction spectra. This what my lab book says: Verify and calibrate your spectrometer, by measuring Hg and Ne. Measure ...
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103 views

Spreading UV light? Fresnel lenses?

I'm making a little UV exposure box and I'm looking for a way to evenly spread out the UV light. I've used Fresnel lenses to do just this in the past, but that was for visible light. But from what ...
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0answers
114 views

C Method for Diffraction grating

Alright, so I am trying to find the efficiencies of a coated diffraction grating through the method in this paper. This is through a change of coordinate system. So I went through and derived all of ...
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0answers
65 views

Is there spatial data loss in light passing through transparent crystal?

There is perfect parallelepipedal bar made of transparent crystal with cubic lattice floating in vacuum. Faces of parallelepiped are parallel to lattice axis. There is image, forming checkerboard ...
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0answers
78 views

about wavefunction and vector entries

I am beginer of physics and I am studying some very fundamental idea of quantum mechanics by myself. In the introducing book I am reading, there is an example to show a particle diffraced by a slit or ...
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14 views

Question about dark fringe in diffraction

In finding the angle for the mth dark fringe of single slit diffraction using Huygen's principle, they usually split the slit into equal portions. For example, to find the first dark fringe the slit ...
0
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0answers
27 views

How to design a grating coupler to produce surface plasmon-polaritons (SPPs) at a desired frequency?

Following on from this question, which I found very useful on the topic, I was wondering how you would use the equation $\beta = k sin \theta \pm \nu g$ to fabricate a grating coupler to generate SPPs ...
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37 views

Is the human eye diffraction limited, or is there another limiting factor?

I know that most problems involving the human eye in my undergrad physics text book tell the student to treat the human eye as a diffraction limited system (ie to assume the only factor limiting human ...
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0answers
20 views

Single slit diffraction treated as a differential equation

I want to find the values of electromagnetic fields that result from single slit diffraction. This should be possible by solving maxwell's equations for appropriate boundary conditions. But I'm not ...
0
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0answers
19 views

Deviation on the Diffraction Pattern when not perpendicular

Due to Babinet principle, Diffraction pattern of an opaque .... ( you all know ). here my opaque is my wire. So, I know that if I change the angle between beam and wire ( I mean if I don't aim the ...
0
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0answers
42 views

What is the electric field of a diffraction grating?

I'm trying to follow the equations in "Introduction to Modern Optics" by Fowles. He starts out with equation for a single slit of length $L$ and width $b$: $ U_p = C \int \int e^{ikr} dA $ where $U$ ...
0
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0answers
71 views

How are lattice parameters determined from reciprocal space maps?

It seems that the papers speak of reciprocal space maps with very high praise because of its ability to study strain in epitaxial films and determine the amount of relaxation. Also one can determine ...
0
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0answers
48 views

Relativity - Diffraction Of Light

Following thought experiment. Inside a rocket, right in the middle, we place two lasers pointing in opposite directions. Both emitting the same wavelength. The Left wall of the rocket is L1 while ...
0
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0answers
27 views

How to estimate the lattice parameter from a Debye-Scherrer diffractogram

The question is: In a Debye-Scherrer diffractogram, centers of maximum intensity were noted at the following angles with respect to the straight through position (all these angles are in degrees): ...
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0answers
5 views

How report that bragg reflection from PVC filters is greater than polypropylene filters?

I have been told that PVC filters will give a higher background in XRD analysis due to the high absorption of the Cl component. My argument is that another filter material should be used when ...
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0answers
53 views

Fringe Localisation

How am I to understand where the fringes of a given setup are localised? For example, Young's double slits have non-localised fringes, that is the fringes are localised (and so are well formed) at ...
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0answers
37 views

Trying to understand electron diffraction

I'm trying to understand how electron diffraction works, but I'm not really getting it. Here's an image Here are a couple of questions about it that I can't figure out. Why is the angle of the ...
0
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0answers
72 views

Intensity of waves in single-slit diffraction

So I am trying to determine the relation between intensities of waves in single slit diffraction. Since I am pretty new to this topic, I couldn't find a way how to calculate the ratio between the ...
0
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0answers
15 views

How do I derive Sommerfeld's solution of the case when the incident ray is aimed obliquely to the edge of the screen?

I already know that the Sommerfeld's solution to this problem is conical. But internet does not show me the simple of exact derivation of this solution. How do I solve this problem?
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0answers
50 views

Huygens and philosophy of the slit

A single (narrow) slit diffraction pattern, can be explained/described classically with Huygens' principle (1678), and quantum mechanically with the Uncertainty principle. If the pattern on the screen ...
0
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0answers
53 views

Diffraction of a thin mirror

I have a question about a particular case of light diffraction. A laser light collides into a "hairline" mirror (I mean a straight line mirror that halves the wavelength dimension), see the image ...
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66 views

Reason behind formation of doublets in diffraction spectrum

like if you see is Sodium (and also in Mercury), there are two discrete lines of Yellow color.. What's the reason behind formation of doublets?
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0answers
208 views

Relation between size of obstacle, wavelength and diffraction

"If the boundary is merely an obstacle implanted within the medium, and if the dimensions of the obstacle are smaller than the wavelength of the wave, then there will be very noticeable diffraction of ...
0
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0answers
37 views

Band-limited double-step Fresnel diffraction for images with radio waves?

Is it possible to use band-limited double-step Fresnel diffraction to assemble a holographic image with radio waves? If not is there a simular principle?
0
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0answers
62 views

Bandpass of diffraction grating - exit slit width?

I'm supposed to derive a relation for the range of wavelengths that's being transmitted by a spectrometer (bandpass) in terms of the dispersion, focal length and exit slit width. Given grating is ...
0
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0answers
42 views

diffraction from sphere solution

I want to solve a problem of plane wave diffraction by a large sphere. There is a formula that I found from papers, but I think needs numerical solution. please help me to solve it The formula is ...
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0answers
83 views

Diffraction grating zeroth order intensity

I don't understand how the zeroth order intensity maximum works. The intensity of a transmission diffraction grating is: $$I=I_0\sin^2(β/2)/(β/2)^2\sin^2(Nγ/2)/\sin^2(γ/2)$$ Where $γ =kd\sin(θ)$, ...
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0answers
35 views

Close to diffraction grating

Being interested in the diffraction of a coherent laser close to the diffraction grating, I find nowhere what the pattern looks like relatively to the distance between a diffraction grating and the ...
0
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0answers
90 views

Why do I get different colours in scratched holograms?

I was making a scratched holograms and in result got different colours instead of white hologram
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949 views

Simulating the Interference Pattern of Fraunhofer Diffraction by a Single Slit

I'm attempting to simulate the Fraunhofer diffraction pattern due to a single slit. We know that the intensity at an angle $\theta$ is $I(\theta)=I_0 \text{sinc} ^2(\beta)$ where ...
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0answers
58 views

Bass and Treble-Car Steroes

In a car which phenomenon, diffraction or the resonant frequency of the car, lends itself more to the ability of bass to go farther? Related Answer: Why do bass tones travel through walls?