Questions tagged [interference]

Interference describes different waves superposing to form a resultant wave of greater, lower, or the same amplitude. Normally, it involves interaction of waves that are correlated (coherent) with each other, either because they come from the same source, or because they have the same or nearly the same frequency. Interference effects can be observed with all types of waves, e.g., light, radio, acoustic, surface, or matter waves.

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Double Slit -> $N$-Slit: Does Which-Way Information change in terms of number of bits?

Suppose an electron is fired through a double slit. We all agree that the electron is now non-deterministic, and will arrive at its destination in a single spot, but it will have travelled there as a ...
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How can photons destructively interfere?

This is a concept I don't fully understand. If I have two photons each with frequency $\nu$, then they each have an energy of $E = h\nu$. If they get matched with an inverted phase, then the summed ...
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Waves interference in terms of fields and intensity

let's suppose that two electromagnetic waves (let's focus for instance on their electric fields) with same amplitude A and frequency, but with a difference $\Delta\Phi$: E_{1}=A\cdot \sin\left(kz-\...
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How does light look like when it is 180° out of phase? [closed]

When two lights are 180° out of phase, would it look like this? In the photo below, the left side is flipped and it is a mirror image.
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How is Electromagnetically-Induced Transparency a result of "destructive quantum interference between two pathways"?

It has been described that Electromagnetically-Induced Transparency (EIT) is a result of "destructive quantum interference between two pathways." To quote from this source: In these simple ...
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Why is the phase difference an "odd number of half-wavelengths" when two waves interfere destructively? [duplicate]

Excerpt from the Feynman Lectures, Volume III, Quantum Behavior (emphasis mine): At those places where the two waves arrive at the detector with a phase difference of π (where they are "out of ...
474 views

Are two waves out of phase only when the phase difference is $\pi$?

Excerpt from the Feynman Lectures, Volume III, Quantum Behavior: At those places where the two waves arrive at the detector with a phase difference of $\pi$ (where they are “out of phase”) the ...
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Where does the energy vanish in wave interference? [duplicate]

In my physics textbook there is a chapter on waves. Now there is a topic on interference. I don't understand why I get additional energy there. Suppose two waves presented as $Y_1=3\sin(\omega t)$ and ...
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When will iridescence only happen when seen through a mirror-like surface?

The phenomenon is: A semi-opaque semi-rigid plastic sheet covers a window, if you see the sheet directly from any direction, there is no iridescence on the sheet. But if you see the sheet through a ...
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Two different beams of same frequency light passed through the double slit

We all know that when one beam of discrete frequency passes through the double slit makes an interference pattern. What is interesting to me is that in that case the beams which diffuse from the slits ...
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Can two perpendicular beams cancel each other out?

This question is related to the Michelson-Morley experiment. See below an illustration of the setup: When looking at this image, I am wondering where and how exactly the interference occurs. Is it ...
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Relation between slit width and intensity of light in Young's double slit experiment [duplicate]

In some places , it says slit width is directly proportional to intensity while in other places intensity is directly proportional to (slit width)² .
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All the information (photons) within a unit cube of space [closed]

So here is a thought, lets fix a cube of side 1cm, it contains light passing through it from all possible angles, be it stars or insect. If we change our angle of view we can see different objects due ...
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Electron interference

As I have understood, as per QM, electrons could behave as waves in a double slit experiment, i.e. form dark and bright bands, albeit after sufficient electrons have been shot from the source. Also, I ...
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Probability density in double slit experiment

I don't understand why the probability density in the double slit experiment in the case of both slits opened, has a minimum corresponding to the maximum of intensity. Shouldn't $P_{12}$ have the same ...
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Is “reflecting back” an intrinsic property of water waves?

I have come across an interesting answer here on Physics SE which states that you get standing waves when you throw a rock in a lake, because of an “intrinsic property” of even dimensional waves. “(......
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Huygens' principle: Its correct interpretation, and why there is no destructive interference in every wave? (unsatisfied with current answers)

My understanding of Huygens' principle is, that it describes the way how a wave moves: Instead of moving straightforward, it propagates in all directions via producing secondary wavelets. 'Secondary ...
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Non-quantum explanation for Mach-Zehnder interferometer effect

The phenomenon of all photons being detected at only one detector seems quite reasonable to me, classically. If a photon gets deflected at the first beam splitter for whatever reason, it gets ...
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Superposition of Microwaves experiment? How does it work?

Please can someone help me out with this experiment and see if this is correct? So the experiment consists of one metal sheet that fully reflects microwaves (and is fixed in its position), and the ...
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Interference : the cause of current

The wave nature of electrons was proved in the Davisson and Germer experiment since the Galvanometer they used showed a sudden peak in the value of current. Now I have some doubts regarding this. 1 : ...
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Why does small angle approximation work for Young's double slit and not for single/multiple slits?

I understand that for a double slit experiment the equation is $\lambda=xd/L$, which has come from the small angle approximation of $d\sin\theta = n\lambda$ by assuming that $\sin\theta = (x/L)$ and ...
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If a photon truly goes through both slits, then why can't it make two dots (excite two atoms) in the screen? [duplicate]

There are a lot of questions on this site about the double slit experiment, none of them answer my question specifically. I am not asking about detection or detectors or anything just at the slit. My ...
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Why does a rainbow pattern appear, in a picture I took with my mobile in the mirror with flash?

I took a picture in the mirror with a flash (and in a flash). This was the result: After a comment made below by @SuperfastJellyfish (indeed widening occurs), I made another picture (this time in the ...
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Phase difference between electrons emitted from a photoelectric setup of Cs

I read that electrons being emitted from a Cs plate when irradiated with photons with energy greater than work function of Cs, are used in a double slit experiment. But, should they not have varying ...
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Why is the diffraction pattern like the interference pattern as opposed to a smooth band?

Why are diffraction patterns similar to interference patterns? I understand interference patterns but I can't wrap my head around as to why the diffraction pattern would be similar? Does diffraction ...
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Is it possible for an interference pattern to appear while experimenting with entangled photons? [closed]

An specialist in quantum information asserted that "entangled photons will never show an interference pattern", but that seems to contradict the response to another question I made here. He ...
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Interference and Fermat's principle

Fermat's principle states that light always takes the path for which the optical length is stationary. \begin{align} \delta\int n(\vec{r}) \:\mathrm ds = 0. \end{align} Furthermore, it is equivalent ...
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Should two laser pointers always shine a point on the screen with same intensity? [duplicate]

Lasers are coherent beams so they can be totaly cancelled out if applied a source out of phase of 180 degrees. So the question is simple... do two different coherent lasers of same luminosity when ...
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How does an electron move around as a wave in orbitals?

This question arose when I was told that there were positive and negative lobes in an orbital. I wanted to know on what basis this was proposed and hence I searched it on web and found out that it ...
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Is the universal wavefunction globally coherent?

In Wikipedia's article on quantum decoherence, it states that despite decoherence creating the appearance of wavefunction collapse, A total superposition of the global or universal wavefunction still ...
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Double slit experiment: Single photons of red light mixed with high intensity infrared light

First this is only a presumtion. Let say we fire single photons of red light at the double slit to get a interference pattern on the screen. The distances between frindges would have certain ...
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Is it possible to register the effects of sound interference in everyday settings? [closed]

For example, sound interference could lead to a loud room feeling louder simply because of sound waves colliding. Or an orchestra which is perfectly synchronized could create loud and quiet spots in ...