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 ...

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How can laser interferometry be used to measure path difference smaller than wavelength of laser light?

The currently proposed Gravitational wave detection apparatus consists of Michelson Interferometer which is supposed to measure distances of the order of $10^{-22}$m. But the wavelength of the light ...
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0answers
28 views

Interference on curved film

Let's say I have a curved film in the XY plane, delimited by $y=0$, $y=\sqrt{x}$, $x=L$. Now I light the thin film from the top and I try to see the interference pattern by transmision. I'm stuck ...
6
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4answers
426 views

Explanation of Michelson Interferometer Fringe Shift

I have been working on an experiment where 2 glass microscope slides are pinched together at one end (so that there is a "wedge" of air between them) and placed in the path of a laser in one leg of a ...
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2answers
138 views

Why light comes out in spherical form after passing through a slit (diffraction)?

I want to know why light comes out in spherical form when it passes through the slit? I know this is due to diffraction but how? And my second question, if there is no difference between ...
2
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2answers
157 views

Wheeler's delayed choice experiment

In Wheeler's delayed choice experiment (http://en.wikipedia.org/wiki/Wheeler%27s_delayed_choice_experiment) When the experimental apparatus does not contain a final interfering mirror, the photon is ...
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1answer
79 views

Michelson-Morley experiment

I have to do an experiment about light. I preferred to measure the speed of light by the experiment of Michelson and Morley. When you do the experiment, it will result in an interference pattern by ...
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1answer
93 views

Difference between thin film interference and Bragg diffraction of electron

Thin film interference is given by: $2dsin\theta=n\frac{\lambda}{n_i}$, where $d$ is the thickness of film, $\theta$ is the angle between incident light and tangent to the surface, $n$ is an integer, $...
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2answers
127 views

Post mortem measurement of particle-wave duality

I was wondering what the outcome of this experiment would be: You shoot single photons at a double slit. On their way there you preform a measurement in $x$ so you get the time ($t_0$) the particle ...
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2answers
340 views

Explanation of Interference of Electromagnetic Waves

There is a question on a test which goes like this: "Given two electromagnetic waves, one of wavelength 6.0 X 10-7 m and the other of wavelength 7.0 X 10-7 m, travelling in space. When the two ...
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0answers
33 views

PM-IRRAS Equidistant Fringes in Spectrum

What is the cause, and best method to prevent / minimize, fringes in one's FTIR (PM-IRRAS) spectrum on samples deposited on a thin metal film? The fringes look as though they are spaced out by a ...
2
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0answers
39 views

Limits on the information obtained through optical measurements

Consider a Gedankenexperiment shown in the figure below. There are two lasers $S1$ and $S2$ with exactly the same specifications on paper. In practice, they are of course somewhat different but ...
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3answers
202 views

Violation of conservation of energy?

Imagine a perfectly spherical mirror with 100% reflection. Imagine a point source of light in the center. The point source keeps radiating light. Will the light undergo destructive interference ...
2
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1answer
233 views

Modified double-slit experiment - two electron sources instead of two slits

In the famous double-slit experiment, if I inserted two identical sources (i.e electron guns) at the locations of the slits, would I still see an interference pattern on the screen? I would allow ...
3
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0answers
55 views

Fastest path of light [duplicate]

Fermat's principle of least time says that light always takes the fastest path to any point. So how can light know which is the fastest path without taking all the paths first?
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1answer
93 views

Are we working in the double slit argumentation with destructive interference arguments?

Stimulating water with two long straight bars one could produce linear waves. Having the right distance between the bars and the correct frequency of the steady system we get in the middle between the ...
2
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1answer
717 views

Why does a double-slit experiment with sound waves never result in complete destructive interference?

Today, I find a question that if the speakers are set in parallel towards the wall. It has no complete destructive interference due to difference in distance from the point to each speakers, which ...
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1answer
59 views

Rayleigh's Criterion

I was just wondering, when two different objects have have light coming from them to our eyes, do the intensities of each diffraction interfere? For example, in the picture below: Do the ...
2
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1answer
586 views

Wave superposition, is my textbook wrong?

Here's the question: Two coherent electromagnetic waves are incident simultaneously at some point in space. The intensity of each independent wave is $I_0$. What is the intensity of the superposition ...
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1answer
32 views

Disparity between two texts on intensity and phase interference - which is right?

So, I'm learning phase interference. Imagine we have two waves. $$ E_1 = A_0sin(wt) $$ and $$ E_2 = A_0sin(wt+\phi) $$ With $$ \phi = \frac{2\pi}{\lambda}dsin(\theta) $$ Which is the path ...
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1answer
559 views

How to derive path difference ($\Delta l=d\sin \theta$) for double-slit interference?

The Wikipedia page for the double-slit wave interference experiment states that the path difference between waves diffracting from the two slits is equal to: $$ \Delta l=d\sin \theta $$ where $d$ is ...
3
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2answers
340 views

How to interpret single photon interference when the two possible paths are different in length?

Here is my question. I struggle with the definition of single photon interference. Let’s assume we have a Michelson interferometer and the interference pattern we observe is a single photon result, ...
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1answer
44 views

Fabry-Perot Spectroscopy

Suppose you have a source of variable wavelength, and you are sweeping the wavelength while monitoring transmission through a Fabry-Perot cavity at normal incidence? What (qualitatively) could you ...
2
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1answer
70 views

How does energy get transfered from destructive interference point to constructive one?

If there are two pressure waves (like sound waves) that travel in opposite directions and have the same amplitude then destructive interference occurs: one wave will compress the air particle (here ...
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1answer
73 views

Interference and windows

The other day i was learning about interference patterns with the effect of a bubble making a rainbow on the surface. I learned that the reflections from both sides of the soap can interfere ...
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2answers
171 views

Is the interference quantum mechanical superposition the same as entanglement? [duplicate]

Are the interference of two wave functions an equivalent way of saying that they are entangled?
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0answers
86 views

How is a particle observed in the double slit experiment?

I'm having some trouble understanding what is causing so much confusion what this experiment is concerned. As I understand it it is thought that the wave interferes with itself when it's observed, ...
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1answer
84 views

Interference of waves

Every thing has a dual nature. So if we take waves(consider light interference) as particles, exactly what happens during interference (both constructive and destructive)? Can you explain in easy ...
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1answer
249 views

Spherical waves superposition [closed]

If two spherical waves are produced by two sources $S_1$ and $S_2$ as described in the picture From the superposition principle, we know that : $$\Psi(M,t) = \Psi_1(M,t) + \Psi_2(M,t) = \frac{A_1}{...
6
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1answer
138 views

Can gravitational waves resonate?

Can gravitational waves resonate? - Perhaps by creating standing wave interference in a cavity? Could that feasibly happen either in nature or by engineering?
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2answers
189 views

Coherence length interference pattern

I recently watched this video that illustrates a laser's coherence length: https://www.youtube.com/watch?v=LixwAXsN8vg I've learned in class that coherence length of a laser with several wavelengths ...
4
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2answers
149 views

Michelson interferometer interference pattern [duplicate]

My friend and I recently did an experiment on Lasers where we shot a laser beam through a Michelson interferometer and observed the interference pattern on the wall. Here is the basic setup: One ...
0
votes
2answers
130 views

multiverse fabric of reality

Source-"fabric of reality"- author d. deutsch - his contention, as I understand it, is that quantum interference is caused by "almost, but not identical quite quantum entities" , e.g. electrons, from ...
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1answer
59 views

Paradox of wave energy

Imagine that a wave with energy $E$ is given. as we know $E$ is relevant to the $A^2$($A$ is amplitude) now consider another wave (as same as the first one) and these two wave having a constructive ...
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0answers
57 views

Resolving multipath interference when modelling radio wave propagation

I am creating a raytracer to model the propagation of radio waves from a simple router. I am assuming that the rays have a frequency of 2.4GHz and a velocity of the speed of light. The router has an ...
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1answer
270 views

Conservation of Energy in Double Slit Experiment

How is energy conserved In Young's Double Slit Experiment ? In destructive interference , energy is lost . So what happens to that lost energy ? Does it escape as heat ?
4
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1answer
148 views

How to check whether Schrödinger's cat was in superposition of states?

Suppose we can make an arbitrarily precise preparation of a Schrödinger's cat (and isolate it arbitrarily well so that decoherence is not a problem). If we prepare lots of cats in this state, what ...
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1answer
35 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
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1answer
42 views

what is the explanation of the conditions of interference? [closed]

I know the conditions of interference.but I want to know the explanation of the conditions.like we know for interference,the sources should be coherent.but why? I want to know those explanations.
0
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1answer
232 views

What happens to the velocity distribution during constructive interference?

Two pulses(one inverted & having velocity in the opposite direction) moving towards each other with same wavelength & amplitude after undergoing destructive interference do re-appear. Why? ...
5
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0answers
47 views

How was Fizeau able to measure interference fringes in his experiment of 1851?

I am wondering how Fizeau, in the famous experiment of 1851, was able to measure changes in the interference fringes given that he used Sun light. Sun light consists of all kinds of wave lengths and ...
0
votes
1answer
382 views

Why are transition amplitudes more fundamental than probabilities in quantum mechanics? [duplicate]

I am reading Quantum Theory: Concepts and Methods by Asher Peres. Terminology used in the book: $P_{\mu m}$ are "transition probabilities". They are the squares of "transition amplitudes". That is, ...
0
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1answer
93 views

Is electron interference because of energy transformation from wave to particle and vice versa?

I read about electron interference that in presence of photons there are no fringes formed but in its absence fringe patterns are formed. Can it be explained like this. An electron travels free as a ...
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2answers
133 views

Combination of 2 photons in opposite phase

We can explain conservation of energy in interference phenomena by saying that there is redistribution of energy. However if only 2 photons in opposite phase "combine" then how can we explain ...
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1answer
65 views

Between Constructive and Deconstructive Interference

Is there something other than constructive interference, such as a shift in 1/4 λ or 3/4 λ or even 7/5 λ? Because it would not end in a hill or a valley. It would be someplace between. Would it ...
1
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1answer
84 views

The interference pattern of a wave along a line [closed]

Why the answer is B, but not C? Is it true that the pattern cannot go beyond $A_0$ and $-A_0$ at the same instant?
2
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1answer
481 views

Coherence length requirement for interference

One property of light sources that is usually stated, which is of particular importance when trying to create interference fringes, is the coherence length (or coherence time). The equation for the ...
2
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3answers
113 views

Is wave superposition always equivalent to wave interference?

I'm confused when using these 2 words "wave superposition" and "wave interference" since their definition is very similar. So, are these 2 term the same?
0
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2answers
3k views

Does wave interference happen only to same frequency waves?

As the title says, from books and results from internet, I find that examples of wave interference always have the same frequency, only different in phase constant. So, I'd like to know if wave ...
0
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0answers
403 views

Interference of sound: how to calculate the sound intensity at each point?

I need help with the following question: Two speakers are sending out sound in phase with the frequency 2,13 kHz. The sound from the speakers is registered in three points A, B and C. See figure. ...
2
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0answers
102 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 ...