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.

Filter by
Sorted by
Tagged with
1 vote
0 answers
40 views

Does a waveform of frequency $f+\Delta f$ beat against a wave of frequency $2f$?

In the elementary treatment of waves, beating occurs between two waves of similar frequencies because $$\cos(2\pi f_1 t)+\cos(2\pi f_2 t) = 2\cos(2\pi \frac{f_1+f_2}{2}t)\cos(2\pi \frac{f_1-f_2}{2}t)$$...
  • 2,045
4 votes
0 answers
49 views

Does the two slit experiment fall apart if there is dust in the room?

All the pictures and videos of the two slit experiment show the photons hitting the back screen in the interference pattern. Does this fall apart if there is dust in the air and the photons hit a ...
  • 3,748
0 votes
2 answers
46 views

Path integral and interference pattern

I would like to ask you to shed some light on an aspect of the famous Young's slit experiment. It seems to me that the "feynmanian" quantization method allows to obtain observational ...
0 votes
2 answers
22 views

Phase of the standing wave constituents

Do 2 superimposed waves have to be 180/0 degree apart to form a standing wave? It seems to be the necessity for forming nodes of 0 displacement (taken that their amplitudes are the same) but can they ...
  • 136
0 votes
0 answers
19 views

AC electromagnetic waves: interference and sensing technologies

When measuring the magnetic flux density around a current carrying wire it is possible to use a coil (with a ferrite for greater concentrations). These coils are "directionally sensitive" (...
1 vote
5 answers
72 views

How to correlate the frequency of source to The frequency of particle just between the two medium while transmission and reflection of wave?

When a pulse travels through rarer to denser medium,two new waves (reflected and transmitted) are formed from incident wave,While the wavelength of the Transmitted wave differs from wavelength of ...
1 vote
1 answer
34 views

"Time travel" difference in double slit experiment

In double slit experiment, as in following figure We calculate the relative phase via $$\Delta \phi_0 = \frac{2\pi \delta}{\lambda} $$ where $\delta$ denote the two path distance difference in figure,...
  • 551
1 vote
1 answer
29 views

Why wireless radios start making buzzing noise when I switch on some electrical appliances?

This question has possibly been asked a numerous number of times already, by many people in many places, but nowhere can I find a precise answer to my precise question. When I turn on, say a ceiling ...
-2 votes
2 answers
118 views

Bohr interpretation of Mach-Zehnder interferometer

Consider MZI for single photon. Bohr or Copenhagen interpretation holds that the wave de Broglie attached to a particle is just amplitude(s) of probability (e.g. some information which is located (I ...
  • 663
-1 votes
2 answers
62 views

Which is the real reason for why we don't see light interference patterns?

There are many questions like mine in the web, but think I cannot fully understand it. Let's look at this question. The first answer states that we cannot see light interference patterns because most ...
  • 1,139
0 votes
0 answers
9 views

How can the intensity of the center of Arago's spot be calculated?

I am currently working on measuring the relationship between the diameter of the sphere and the intensity of the center bright point of the shadow with Arago's spot. I have been researching with ...
1 vote
1 answer
41 views

Non-interaction between oscillating dipoles (Feynman lectures I.29)

In lecture 29 of volume I, Feynman tackles the elementary problem of the field radiated by two oscillating dipoles separated by different distances of the order of a wavelength. He describes the ...
0 votes
0 answers
23 views

In a Mirau Interferometer what is the distance between the mirror and the beamsplitter?

A Mirau interferometer (shown left in the figure, next to the Michelson configuration to the right) is an important instrument for non-contact surface profilometry. Briefly, taken from Wikipedia, &...
0 votes
1 answer
41 views

Single-photon Mach-Zehnder interferometer with complete destructive interference

This article describes an experiment where you can set up a Mach-Zehnder interferometer, and send one photon through at a time, and see complete destructive interference at one of the detectors (one ...
  • 123
1 vote
0 answers
36 views

Transfer matrix method with inclined boundaries [closed]

It is straightforward to numerically compute complex reflectivity ($r$) and transmission ($t$) of a layered structure with parallel boundaries by transfer matrix method (TMM). Now, if we have a ...
1 vote
1 answer
61 views

Does a double two-slit experiment show an interference pattern?

Here's the delayed choice quantum eraser setup from Kim et al. (1999), from Wikipedia. Don't worry, we're going to throw out almost all of it. An argon laser generates individual 351.1 nm photons ...
1 vote
0 answers
26 views

Double slit experiment: Plotting contributions from individual slits

I'm looking at the double slit interference experiment. I'm trying to plot the answer the question "what is the contribution of each slit to the total intensity". The quantitative solution ...
  • 409
12 votes
3 answers
1k views

In the electron double slit experiment, what is interfering?

According to quantum field theory, an electron particle is an excitation of the electron field. Is it the waves of excitation in the electron field that are interfering in a double slit experiment? ...
1 vote
2 answers
90 views

What if we send humans through the double slit? [closed]

Lets say that we have a universe that has just 3 things inside, me in a specially designed suit capable of keeping me alive while near absolute 0 as to enlarge my de broglie wave-length, double slit ...
  • 137
1 vote
1 answer
56 views

Why does a sound of two sources of same-amplitude come out louder than one-source sound with the same amplitude?

Sorry if the question is stupid. The last time I touched physics was in school and I have never come back to it since. But this question popped up just recently in my life and I realized I don't know ...
  • 287
1 vote
0 answers
140 views

Feynman’s QED explanation of reflection from a small mirror

In the “QED: The strange theory of light and matter” professor Feynman explains at page 45 and following how the simple rule introduced in the first chapter can explain the geometrical law of ...
  • 31
0 votes
1 answer
22 views

What is the path rays in Fabry–Pérot interferometer for calculation it resolution?

A Fabry-Perot interferometer shown in Figure below essentially consists of two parallel plates of glass whose inner surfaces are polished to a very high degree of flatness, and then coated with a ...
  • 2,475
0 votes
1 answer
47 views

Why does t = $\frac{1}{4}$ for destructive interference by parallel-sided thin films?

I knew for destructive interference for reflected light in thin films: 2t = mλ Where t is the thickness of the thin film, m is an integer (0,1,2...) and λ is the wavelength of light in the thin film. ...
1 vote
1 answer
20 views

Interference of Waves question

Given : $\phi_1(x,t)=A\cdot \cos(k_1x-\omega_1t)\hat{x},\phi_2(x,t)=A\cdot \cos(k_2x-\omega_2t)\hat{x}$ with no difference phase,$k_1-k_2 \ll k_1,k_2,\omega_1-\omega_2 \ll \omega_1,\omega_2 .$ I have ...
  • 121
1 vote
2 answers
44 views

Optics - interferometers and interference

I was watching a video of Sabine Hossenfelder, in which interferometers were a topic of discussion. Excuse me if the answer is obvious because I am not a physics pro by any means, just an interested ...
0 votes
4 answers
113 views

Do EM waves cancel out permanently in this example?

If we emit two photon rays one from each source 1 and 2 and after they reflect on mirrors to reach the same trajectory they should cancel out in the case their phases are opposite 100% but will any EM ...
  • 415
1 vote
0 answers
36 views

Interference pattern of an electron passing through a semislit instead through a single slit

Is there a difference in the interference pattern of an electron between cases when it passes through a single slit and when it passes a "semislit", which I drew on the picture below to make ...
  • 415
4 votes
2 answers
123 views

Reason why light beam hits detector

I was thinking about the basic structure of interferometers and I watched a video about it. I came across a simple illustration that looked something like this: A laser beam is split into two ...
1 vote
1 answer
77 views

Why do we need a double slit experiment, when a single slit experiment shows that an electron/photon behaves like a wave? [duplicate]

To demonstrate wave-particle duality, it is often stated that we need to perform a double slit experiment. However, it seems that in a single slit experiment, individual photons or electrons behave ...
0 votes
0 answers
22 views

Crossing lasers, information loss and the human eye query

Let us set up 2 crossing lasers. Laser Source A passes through a projector slide of the Mona Lisa then through a lens to expand and project on screen A. Laser Source B passes through a projector slide ...
1 vote
2 answers
80 views

Double slit with erasure

I have been watching Feynman's fantastic lecture on the double slit experiment with electrons: https://www.youtube.com/watch?v=kEx-gRfuhhk&t=15046s Feynman proposes to shine light on the slits to ...
  • 656
2 votes
2 answers
59 views

Interference or diffraction? [duplicate]

Suppose I have $N$ slits separated by a distance $a$. We are sending a light source of wavelength comparable to the slit width. Then which of the effect should dominate: Interference or diffraction? ...
  • 1,249
0 votes
1 answer
60 views

Is there a reflection when light destrucively interferes on a surface?

Imagine the following setup: I have a coherent single frequency electromagnetic wave (laser beam) that is imaged on a surface. It is reflected onto a detector (photodiode). I can easily take ...
  • 3
0 votes
0 answers
55 views

Does destructive interference of photons destroy energy? [duplicate]

I am wondering about if two light beams comes in opposite phases exactly against each other, destructive interference will happen. From what I have found on the internet many say that energy is not ...
  • 91
0 votes
0 answers
38 views

Interference in Fock state

Source: Mandel_effect According to the above site, When two single photons interfere, $$|1,1\rangle_{a,b}\xrightarrow{BS}\frac{1}{\sqrt2}(|2,0\rangle_{c,d}-|0,2\rangle_{c,d})$$ where the BS matrix is $...
4 votes
2 answers
842 views

Sound waves adding up [duplicate]

If there is a swarm of bees, why is it louder than a single bee? This question may sound stupid but ... if they are all buzzing at the same frequency with the same loudness and the phases of the sound ...
  • 149
-1 votes
1 answer
49 views

How can we derive an equation for double slit interference without the approximations made? [closed]

I'm referring to: $$s = D\lambda/d$$ Where $s$ is the distance to the first constructive interference (CI) from the central line, $D$ is the distance from the point sources to the screen, $d$ is the ...
0 votes
1 answer
42 views

Phase difference and path difference relation confusion

If two light waves of same wavelength reaches the point $ P$, then what is the relationship between path difference and phase difference? In many books I have seen that they assume two 1-D equation ...
1 vote
0 answers
37 views

Gravitational waves and their properties [closed]

To clarify my question. I wanted to ask, "how do I figure out the interference of 2 different gravitational waves?" If we were to spin 2 black holes very quickly and take a cross section of ...
0 votes
1 answer
87 views

Shouldn't it be $d\sin\theta=\frac{\lambda}{2}$ here instead of $d\sin\theta=\lambda$?

Question: The width of a slit is $4\times 10^{-4}cm$. The wavelength of the light used is $6000 A^{\circ}$. What is the angular distance between the two minima of first order on both sides of the ...
1 vote
1 answer
48 views

Path Integral QM and Destructive Interference

In Shankar's QM book pg. 224, it was said that the contributions $Z=e^{iS[x(t)]/\hbar}$ add constructively near the classical path $x_{cl}(t)$ since the action $S[x_{}(t)]$ is stationary here. As we ...
  • 3,879
1 vote
1 answer
125 views

Law of conservation of momentum and interference [closed]

There are two guns a and b that emit electrons simultaneously. Electrons meet at a point с ...
  • 113
1 vote
1 answer
40 views

Intensity of Diffraction and inteferance

Why intensity of bands in diffraction decrease while moving away from central max while that of interference do not?
-1 votes
2 answers
88 views

Why is the width of a dark fringe in an interference pattern much less than the width of a bright fringe?

Photographs of interference fringes show that the width of dark fringes is much less than the width of bright fringes. Why is this so?
0 votes
0 answers
35 views

How to account for signal transmission in measurements of beat frequency between separated senders?

An important technique in optics experiments is the determination of the beat frequency (a.k.a. beat note) between (optical, as good as monochromatic, suitably stable) signals of two senders; say, of ...
  • 4,064
1 vote
1 answer
153 views

Double slit experiment: how to derive the figure of interference?

We know that by performing the Double Slit Experiment we get an interference pattern on the detector screen. To explain this most sources talk about the state of the particle: calling $|\psi _l \...
  • 3,979
1 vote
0 answers
47 views

How is energy conserved in interference of light waves? [duplicate]

How is energy conserved during interference of light waves? I already know a textbook explanation that in constructive interference the resulting intensity is four times the initial intensity and for ...
  • 518
0 votes
0 answers
15 views

Adding an Impurity as a Perturbation to a Simulation

I am working on some plots corresponding to superconductors (of many kinds). If we insert a vortex, we can view this as an impurity and observe the Quasi-Particle-Interference (QPI). How I go about ...
  • 199
0 votes
0 answers
10 views

Why does the fringe pattern of an interference pattern get darker as the anti-nodal lines increase?

Why is it that the constructive interference fringes get darker as the antinodal lines increase? For example the maxima antinodal line:0 is the brightest. Why do they decrease in brightness after that?...
  • 29
1 vote
4 answers
78 views

What is the clear difference between interference and diffraction? [duplicate]

Richard Feynman said in his book. "No one has ever been able to define the difference between interference and diffraction satisfactorily. It is just a question of usage, and there is no ...

1
2 3 4 5
25