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12
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3answers
184 views

Does the diffracted electron radiate photons?

When electron is diffracted after the slit it might follow different direction, than before the slit. That means, that going through the slit it gains some acceleration. And accelerated charge emits ...
5
votes
1answer
128 views

Is that a result of thin-film interference?

Several years ago, I was laying on my bed and had a CD shaped transparent plastic disk (which was covering a 100 CD stack), basically a transparent CD. I don't know why but I took my phone and took a ...
2
votes
1answer
87 views

Diffraction and $k$-space

Regarding diffraction I am a little bit lost reading about reciprocal space and the space of $k$'s. As I understand it the Fourier relationship between a wavepacket $\Psi(\vec r,t)$ and the complex ...
2
votes
1answer
36 views

How many atoms does one need to get reliable crystal information with X ray or electron diffraction?

I know that, in theoretical derivations of X ray diffraction (XRD) or electron diffraction (ED), we always assume an infinite lattice, and, as you make the crystal smaller, edge effects start to ...
2
votes
1answer
308 views

How “wide” is a beam of light? What is its half-diameter?

If you believe ray optics where a light ray is a straight line, a light beam is infinitely thin. If you think of fiber optics, you can guide a whole lot of photons down a fiber only one or a few ...
1
vote
1answer
72 views

Basic rule for diffraction

I'm a high school student. I still don't understand the reflection, diffraction and refraction of light. It seems to me that in concept of quantum physics, reflection is just a process of object ...
1
vote
1answer
72 views

How does a non-diffracting beam form from a converging ring of illumination?

I am trying to intuitively understand the basics of the supplementary text of a recent publication from Eric Betzig's group on lattice light sheet microscopy (1). I am confused by the explanation of ...
0
votes
1answer
28 views

How do I interpret the math relating to diffraction?

The following is a quote from the Haifa Lectures (Mendel Sachs) But if both slits are open, the wave function for the electron penetrating screen S1 is the superposition of states, $(\psi_1 + ...
0
votes
1answer
55 views

Fresnel lens/kinoform: How to model diffraction at the edges of zones?

I would like to find the intensity distribution of light due to the diffraction at the edges of zones on Fresnel lenses or kinoforms. (That is, location of orders, heights of maxima, etc.) I can't ...
0
votes
1answer
74 views

Path Difference Due to Angled Incident Light

If light incident on a diffraction grating makes an angle $\alpha$ with respect to the normal to the grating, show how $$m \lambda = d\sin\theta$$ becomes $$m\lambda = d[\sin(\theta - \alpha) + ...
0
votes
1answer
89 views

Slit width for minimum spot size in electron slit diffraction if involving uncertainity principle

I don't believe the following is an accurate description of the physical but a homework problem to help understanding. A beam of electron of energy 0.025 eV moving along x-direction, passes ...
5
votes
0answers
160 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 ...
2
votes
0answers
51 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
votes
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
votes
0answers
41 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
vote
0answers
27 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
vote
0answers
84 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 around a wire I came to the conclusion that the intensity distributions on an observers ...
1
vote
0answers
33 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
vote
0answers
29 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 $k_\beta$?
1
vote
0answers
84 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, ...
1
vote
0answers
62 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
vote
0answers
37 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) ...
1
vote
0answers
28 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
vote
0answers
104 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 ...
1
vote
0answers
55 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 ...
1
vote
0answers
40 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 ...
1
vote
0answers
87 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 ...
1
vote
0answers
90 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 ...
1
vote
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 ...
1
vote
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 ...
0
votes
0answers
31 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
votes
0answers
11 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?
0
votes
0answers
42 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
votes
0answers
33 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 ...
0
votes
0answers
32 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?
0
votes
0answers
92 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
votes
0answers
32 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
votes
0answers
22 views

Transmission of porous membrane with vertical cylindrical pores

There is some porous dielectric membrane with strictly vertical cylindrical pores. I would like to find theoreticaly optical transmission spectra of this membrane, depending on the bulk material ...
0
votes
0answers
47 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
votes
0answers
34 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 ...
0
votes
0answers
59 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 $γ =kd\sin(θ)$, ...
0
votes
0answers
58 views

Direct optical observation of the Arago spot: what would one see?

The Arago/Poisson spot is an excellent example of a constructive interference of diffracted light. In the traditional experimental layout, you observe projected light on the screen. The theory in this ...
0
votes
0answers
33 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
votes
0answers
85 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
0
votes
0answers
630 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 ...
0
votes
0answers
53 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?
-1
votes
0answers
28 views

Fresnel to Fraunhofer limit

I'm puzzled about what happens when distance L from obstacle to screen is continuously increased from a small value (Fresnel diffraction) to infinity (Fraunhofer diffraction). Please consider four ...