Questions tagged [diffraction]
Diffraction is defined as the bending or flaring of light around the corners of an obstacle or aperture into the region of geometrical shadow of the obstacle. This flaring is consistent with the spreading of wavelets in the Huygens construction. Diffraction occurs for waves of all types, not just light.
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Is this additive mixing or camera image sensor error
I have coupled RGB laser light into 3 gratings on chip and projected the light into the the farfield and put a camera sensor on top of the beam. Here is the setup and the experiment.
What I obsereved ...
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Blazed transmission grating
I'm having trouble figuring out why the max intensity envelop (i.e. single slit intensity peak) would be separated from zero order of the grating, for a blazed transmission grating.
In the left ...
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When is the 3D Dirac delta function a good approximation for scattering?
When discussing X-ray or neutron scattering, it is usually assumed that the scattering potential is of the form
$$V_{\mathrm{eff}}(\mathbf{r}) = \sum_i b_i \delta^3(\mathbf{r}-\mathbf{r}_i)$$
with $...
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Why doesn’t the Fraunhofer diffraction prediction match what we observe with wide single slits in reality?
In experiments with a single slit (using ordinary light or laser light), when the slit width is very large compared to the wavelength , I observe that the bright region on the screen has a sharp ...
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X-ray diffraction "linewidth" due to thermal motion
I was recently learning about X-ray diffraction and I am a bit confused about how thermal motion affects the measurement.
If I understand it correctly, when measuring crystals, thermal motion does not ...
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Can a light reflection from lamp change brightness if we split it into multiple reflections with a diffraction foil?
I'm not a scientist or researcher. I've been watching a video by Veritasium on how light behaves and there was a little experiment in the end. Here is the video with timestamp
According to that little ...
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Diffraction Modeling Question
I'm trying to implement a model for diffraction-limited imaging, following "Microlithography" by Sheats and Smith. You can skip to the bottom for my question, but I'll explain the setup ...
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Confusion in Double Slit Experiment regarding fringes [duplicate]
consider the above demonstration, for double slit experiment. In this one, there seem to be two types of "gaps". one, the type of larger (relatively) gaps,(marked as A) and two, smaller gaps ...
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Why in the derivation of Bragg's law, the incident angle = scattered angle? [duplicate]
In the derivation of Bragg's law in Wikipedia here, they assumed that the incident angle is equal to the scattered angle. But every layer of atoms should act like a diffraction grating. Is somehow in ...
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How a plane wave impinging on a cube is impacting the sides of the cube?
Problem:
In the case of a cube, imagine a plane wave, directed toward the $z$ axis, impinging the $(x,y)$ face of a cube.
I am wondering what happen at the four side faces of the cube ($(y,z)$ and $(x,...
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What is the difference between diffraction and scattering?
In the context of acoustic waves interacting with small particles (for example, in medical ultrasound imaging of biological samples) I often read that when a wave encounters a particle whose size is ...
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What exactly causes this ring pattern phenomenon in optics?
I was observing this very specific pattern that I can not figure out what it is caused by.
These is not a lens flare and it is neither newton ringing pattern I think. It only shows when the aperture ...
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Diffraction through thick media
I want to calculate the diffraction pattern of light using (e.g.) the Rayleigh-Sommerfeld diffraction model.
For this, I am using the Python library Torchoptics.
However, I am struggeling on how to ...
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A new variant of the double-slit experiment
I’m curious whether quantum interference would still occur when using two slits of different shapes – for example, a rectangular slit and a circular slit – rather than the conventional setup with two ...
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Various Expressions for Fresnel distance [duplicate]
I've come across multiple formulas for the Fresnel distance in optics, which describes the transition point between the near-field (Fresnel diffraction) and far-field (Fraunhofer diffraction) regions. ...
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Why don't the electrons hit the gun in low energy electron diffraction (LEED)?
I am learning about low energy electron diffraction (LEED) for my internship and was studying the theory behind it. The first step is to eject an electron beam from a gun that will pass through a ...
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Reference request: How to calculate a straight edge diffraction pattern?
The Physics Stack article of 01/28/2016 on Calculating a Straight Edge Diffraction Pattern does not provide a scientific journal or textbook citation for the equation used. If there is one, what is it?...
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Laue oscillations in X-ray diffraction
I am trying to understand why Laue oscillations occur when performing X-ray diffraction on single crystal thin film samples. When performing these experiments we see oscillations in the intensity of ...
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What is the practical difference between Fresnel diffraction and Fraunhofer diffraction? [duplicate]
Recently, I am studying about waves. I studied about Fresnel and Fraunhofer diffraction. I understand that the difference between Fresnel and Fraunhofer diffraction is that, in the first case, the ...
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Limit for the intensity of a light wave in a non-central maxima of diffraction
I am facing a problem in studying diffraction patterns and it is related to the diffraction maxima. In my book I saw the following statement emphasized text(rough translation from original Romanian ...
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In Young's Double Slit Experiment, what happens if one of the slits is being covered gradually?
I am really confused about the result that we will receive when one of the slits in YDSE is gradually being covered.
My assumption is that since the phase difference is the same, the positions of ...
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Is this diffraction?
So I tried to replicate the diffraction caused by a single slit. I did it with my phone's flashlight and a piece of paper with a cut. I obtained this image:
I tried to cut the slit the thinnest I ...
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Should convolution between point spread function & geometrical prediction of image be carried out before or after magnifying one of the two functions?
In "Introduction to Fourier optics" by Goodman, on page 114 it states that for a diffraction limited imaging system:
The ideal image produced by a diffraction-limited optical system (i.e. a ...
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Why diffraction at $N$ slit only depends on the $\beta$?
I actually wanted to throw the question only, but in the field of optics, different books derive the same relation in different ways with different assumptions and different symbols. So before asking ...
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About spatial energy distribution of light emitted by a laser pointer
This question is triggered by a section in the Veritasium video "Infinite Slit Paradox: Something Strange Happens When You Trust QM" about Feynman's path integral that came out on March 5, ...
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Integral of Airy Disk?
I am attempting to simulate the response of a CMOS sensor and would like to account for an Airy Disk diffraction pattern. This is given by:
$$
I(\theta) = I_0 \left[\frac{2J_1(x)}{x}\right]^2
$$
...
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What is the explanation for different diffraction patterns 1cm behind grid vs. on distant screen?
I have a question regarding the following experiment.
I wanted to see what a laser beam diffraction behind a grid looks like up close. I chose the following set up:
That is, the grid is a combination ...
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Light always travels in straight line but what about diffraction?
It's said that light always travels in straight lines. Even when reflection happens, another light ray is generated by electrons in the mirror , which cancels out the incident light. Refraction is ...
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Derivaton of the smallest spot for a monochromatic beam (Helmholtz equation solution)
Although this is not necessarily a question anymore since I have the answer, I'm still posting it since it took me way to long to get to the answer and maybe others would find it useful. By taking way ...
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What is the intensity of the central maximum in single-slit diffraction? Why is it so?
I am a high-school student and have understood from my textbook that the intensity of the central maximum is the same as the incident intensity for single slit diffraction. I find this strange as ...
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Why do we see multiple Bragg peaks?
I am not sure how to connect the Bragg-law to experiment.
Suppose i let a wavelenght $\lambda$ fall incident to a surface of a metal at angle $\theta$. The wavelenght and the angle are unchanged. then ...
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Is there reflection, refraction and diffraction of gravitational waves? How can it be observed?
From what I understand, these effects happen because the wave travels through media with different properties that can change the wave behavior or block them. Is there something similar with ...
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Will the results from two diffraction experiment under exactly the same conditions be completely identical?
If two electron diffraction experiments are conducted under exactly the same conditions and are randomly stopped at the same time, will the results be completely identical? That is, will the ...
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Shouldn't the difference between the dark and bright be the fringe width instead of distance between 2 consecutive bright or dark fringes? [duplicate]
10th minima is 1 fringe above 10th maxima , so distance to 10th maxima is 10 lambda D / d
So that + width of 1 fringe should hive the distance to 10th minima right?
But distance to 10th minima = (10+1/...
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Shouldn't the fringe width be the diff bw a dark and bright fringe instaed of distance bw consecutive bright or dark fringes?
Distance to 10th maxima =10lambda D/d
Distance to 10th minima 10.5 lambda D/d
So should the fringe width be 0.5 since 10th minima is 0.5 above 10th maxima so shouldn't it be rhe fringe wid th, if not ...
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Diffraction Slit Quantum Effects
In 2D, consider an infinitely thin barrier line $(x,y_0)$, $y_0>0$, with a slit through it at $(-a<x<a, y_0)$. This line is between the source and the target of a beam of objects small enough ...
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Why does an infinitesimal slit act as an isotropic light source
For a finite slit, the expression for irradiance is as follows,
$$I=I_0\operatorname{sinc}^2\beta$$
where
\begin{array}{ccc}I_0=\frac{1}{2}\left(\frac{bE_r}{r_0}\right)^2&\text{and}&\beta=\...
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Questions about Huygen's principle and diffraction
I'm going to ask about why wavelength and gap size affects diffraction. I'm aware this is a question that has been asked before here in various forms but reading through those answers hasn't been able ...
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The diffraction of the Gaussian beam on a curved mirror?
I am studying diffraction. While going through multiple examples, I have understood the diffraction of plane waves passing through a finite size lens. However, it is not easy to qualitatively think ...
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What actually is diffraction? [closed]
According to Huygens the slit has aether in it and hence generates secondary wavelets. But after the Michelson Morley experiment which failed to find the existence of aether and keeping in view the ...
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Why do electrons not pass through a screen?
Rutherford aimed alpha particles (helium nuclei) at a gold foil and found that most of them went right through and only a few bounced back. If we aim deuterium nuclei (deuterons) at a gold foil we ...
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Gerchberg-Saxton algorithm noisy phase retrieval
I am trying to reconstruct a phase-only diffraction grating that produces $n$ beams of equal intensity.
Specifically, I am trying to reconstruct a 9-beam phase profile with the following form:
$$ \phi(...
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Single Slit Diffraction Using White Light
So some days before i prepared a single slit using razor blade and taken mobile flashlight as white light source and tried to do single slit diffraction with white light but what happens that i do ...
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Point Spread Function and Circle-of-Confusion
I have a renderer and am trying to incorporate realistic distortions to it.
My understanding:
Point Spread Function (PSF): For a diffraction limited optical system, the PSF describes how light from ...
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Will we get any diffraction pattern in this case?
We get to see diffraction patterns when light from a coherent source passes through a thin slit. But consider a mirror with a line scratch on it (as shown in the figure) and we shine a red light from ...
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Why are X-ray diffraction (XRD) peaks the same for some different lattice planes?
I have some XRD measurements of a sample and wanted to compare them with the literature to find out the quality of my sample. To my understanding, the XRD peak for my sample corresponds to the (001) ...
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A diffraction pattern without central maxima?
In some smartphone charger there exists a bulb (LED) most probably which emits light when charger is plugged in. I have noticed that light coming from that bulb causing diffraction pattern on the wall....
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Why we obtain dark fringes in Fresnel's diffraction experiment?
There is only one source of light so technically no interference should happen , when no interference is there then there should only be bright light plane , but somehow dark and white fringes are ...
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Why must slit be of order $\lambda$ for radial diffraction?
I've read quite a few posts asking a similar question but I suppose I'm still not quite satisfied with the explanations (hence the question).
I'm aware that diffraction always occurs and I know the ...
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Structure factor of FCC
I know that the structure factor of FCC in conventional basis is
\begin{equation}
S=1+e^{iπ(h+k)}+e^{iπ(l+k)}+e^{iπ(h+l)}
\end{equation}
Now if I change the basis to the primitive basis, the new ...
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