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
votes
0answers
49 views

Confusion regarding the reasoning for why constructive interference is hard to determine in Single-Slit Experiment

We know that the location of dark spots in Single-Slit experiment is given by the following equation: $$m\lambda = d\sin\theta$$ Where $m = 1,2...$ $d$ is the width of the slit and $\theta$ is the ...
1
vote
1answer
48 views

Do noise-cancelling headphones make a lot of unheard noise?

The way noise cancelling headphones work is by listening to sound, and created the inverted sound to 'cancel it out'. Doesn't this mean that the headphones create double the amount of noise, but our ...
1
vote
0answers
67 views

When two photons annihilate each other through destructive interference, where does the energy go? [duplicate]

When two photons annihilate each other through destructive interference, where does the energy go? Perhaps this is only answered by ‘wave type’ questions and answers? Does the conservation of energy ...
1
vote
2answers
56 views

Multi electron interference in double slit experiment

Electrons have negative charge, and therefore repel each other. That should mean that their position, and momentum probabilities should get skewed away when in the presence of some other electron. I.e....
0
votes
1answer
53 views

If I know in advance I'm getting an interference pattern, wouldn't I have time to remove the splitter so the which-path information would be know?

Check the image below, from this excellent explanation of the quantum delayed eraser. My question, and please forgive me if it is a naive one, is that first the photon reaches detector A, which tells ...
8
votes
5answers
2k views

Can two waves interfere head on?

Can two waves (like sound or electromagnetic waves) interfere head on? If yes, and suppose they are out of phase with each other and thus interfere destructively, where does the energy of the waves go?...
3
votes
3answers
108 views

Can there be interference between a proton and an electron?

For example, we know that we can interfere two different electrons or two different protons by employing them in a double-slit experiment. Now suppose, we mix protons and electrons and shoot them ...
1
vote
4answers
69 views

Will two coherent sources of orthogonal polarization angle form the known interference pattern or there will be difference?

if i have a laser beam then i split it into two beams with ratio 1 : 1 then i take one of them to change its polarization angle (90) degree by passing it through an optically active substance then we ...
0
votes
1answer
31 views

Thin film Interference pattern

Why exactly for this minima condition is: path difference = $(2n-1)\lambda/2,$ instead of $(2n+1)\lambda/2$? And what is the starting order of minimal here? Also, what does a negative path difference ...
1
vote
0answers
22 views

What do fringe patterns have to do with VLBI?

I think I have fundamental confusions with how VLBI works. I don't know why: Resolution increases when incident rays meeting to a focal point from a farther separation along an axis perpendicular to ...
3
votes
0answers
19 views

Maintaining phase relationships and other general principles of interferometry

I have a few confusions with some basic principles of interferometry. Bob Campbell's So you want to do VLBI writes: Phase relationships among all points on the wavefront will be preserved ...
1
vote
1answer
21 views

Difference between 'white light' and spectral light for rings of Newton

In my book of waves and optics, there's a chapter about the rings of Newton and as a question there is: how is the interference pattern when we use white light, considering me it's : there are rings ...
0
votes
2answers
41 views

Michelson interferometr electromagnetic wave formula [duplicate]

I don't understand why we use this formula: Instead of this formula: I mean, why we ignore $\omega\cdot t$ part.
0
votes
0answers
5 views

Relationship between spatial coherence and location of interferences

When using an extended source to create interferences, let's say in a Michelson Interferometer setting, it's necessary to use some kind of lens to be able to see the interferences. It is also true ...
0
votes
1answer
12 views

Why do we need cross-polarised light for observing conoscopic interference patterns?

I've performed some experiments for projecting conoscopic interference patterns. In some set-ups are used two circular polarizers one before and one after the birefringent crystal. I can imagine that ...
1
vote
2answers
40 views

Formulae for destructive interference [closed]

There are two formulae for destructive interference. In which situation do we use them? $$(n+1/2)\lambda $$ and $$(n-1/2)\lambda $$ I'm confused as my book has mentioned the first one but In ...
0
votes
0answers
26 views

Destructive interference by a hard boundary

" Wavefronts on reflection off of a hard boundary ( rigid boundary ) have their phases inverted. " This is something I've learnt. " Waves with same amplitude and opposite phases destructively ...
1
vote
1answer
78 views

How did scientist get photos of wave function of electron in the double slit experiment?

In the double slit experiment I know that the electron fires as a particle one at a time then splits goes through both slits and recombined and interferes with itself and hit the wall creating a ...
0
votes
2answers
51 views

Least-square fitting to data (sine function): what is the error of the derived fit parameters?

I have a set of data. I want to fit it to a sine function of the form : \begin{equation} f(x)=A sin(\omega x+B)+C \end{equation} I use the least-square method to find the appropriate fit-parameters ...
1
vote
1answer
42 views

Photon bunching and polarizers

I'm trying to understand how polarizers affect bunched photons. Or, more generally, how a projection operator affects a two-photon state corresponding to photon bunching. Toy example: Imagine you ...
0
votes
1answer
58 views

Diffraction pattern vs Interference pattern

I am not confused with difference between Young's double slit experiment and diffraction. In Young's double slit experiment, the interference pattern is bright fringes separated evenly with ...
0
votes
1answer
42 views

Would a million slits experiment works?

I read that in triple or more slits experiment, the particle can sometimes though lower probability of going through all the slits and interfere with itself many times at once? I used to think it is ...
0
votes
1answer
65 views

Single photon interference, state “top” current theory [duplicate]

Is there a simple generally accepted explanation for single photon interference? Does each photon interact with or see both slits?
0
votes
1answer
21 views

Wavelength and Lattice constant - need to be the similar magnitudes to have interference?

I was taught that they need to have similar magnitudes but I did an exercise last week and the magnitudes were different by 3 decimal places. Before I also noticed them being either the same or maybe ...
0
votes
1answer
26 views

Macroscopic objects - Interference

In Mcintyre's QM book he writes: What does he mean by "a macroscopic object strongly interacts with the environment" for there to be no interference? Why/how does the wave function of macroscopic ...
3
votes
1answer
59 views

Why does light show a no interference result?

I was reading the first chapter in the Feynman lectures volume 3 about quantum mechanics and I understand the concept that 'interference' means $P_{12}=P_1+P_2$ as expected, however when the electron ...
3
votes
1answer
46 views

Bubble optics, impact

My 8 years old daughter was blowing soap bubbles. Most of the bubbles had color. She randomly choses a bubble with colors and lands it on the wand. Instantly it's color is gone. If she blows this ...
1
vote
1answer
29 views

“Partial” Total Internal Reflection

Can partial TIR happen? Consider the image present in this link Here, at point D, TIR happens, but also there is transmission. Is "total" internal reflection a misnomer?
0
votes
1answer
43 views

Confusion regarding path difference by glass lab in YDSE

If in a YDSE experiment the setup is immersed in a medium $n_{med}$, and a glass slab of thickness t of another medium $n_{glass}$ is introduced in front of one slit, then is the path difference due ...
0
votes
0answers
33 views

Air wedge interferometer (Fringe separation)

From Hecht optics, From the setup, $ \alpha = \frac {d}{x}$ $--> d = x \alpha$ $d$ is the varying thickness of the air wedge The condition for constructive interference, $ ( m + \frac {1}{2} ) \...
6
votes
3answers
209 views

How can a double slit interference pattern be created without out going through a double slit

When I create a double slit in a mirror by removing the paint and silver I get a beautiful interference pattern. What’s interesting to me is that I get one in the opposite direction too. What has me ...
0
votes
2answers
184 views

Fringes of equal inclination (Haidinger fringes) Why is the interference pattern circular?

From Hecht optics 5th edition: It says 'With an extended source, the symmetry of the setup requires that the interference pattern consists of a series of concentric circular bands centered on the ...
2
votes
2answers
38 views

What kind of light coherence is required for an image

If 1- Optically speaking, an image point (or pixel) is a light interference pattern 2- interference patterns require phase coherence then 3- the source of the image point must emit coherent light ...
0
votes
1answer
54 views

Physics Young's Double Slit Problem

In a Young's Double Slit experiment, the separation of four bright fringes is $2.5\ mm$, the wavelength of light used is $6.2 \cdot 10^{-7}\ m$. If the distance from the slits to the screen is $80\ cm$...
0
votes
1answer
40 views

Possible to change optical properties of tissue?

I am looking at an optical coherence tomography scheme which is based on a michelson interferometer. The basic idea is that a laser beam is split by a beamsplitter, half of which goes into some tissue ...
3
votes
2answers
47 views

Time-of-flight vs. which-path information for single photon interference

I wonder how different path length and therefore different times required for each path lead to interference. Wouldn't it be in principle be possible to tell which path was taken by looking carefully ...
2
votes
3answers
69 views

Why oil films still have color when illuminated by an incoherent source (sun) at oblique incidence

I understand how coherent light can produce interference patterns with a thin oil film. However the sun is a spatially incoherent light source. How can it be that at oblique incidence I still see ...
1
vote
0answers
18 views

How can I focus a laser in the gap between two slits?

I’m trying to focus a green laser in between two slits. The slit width is 0.2mm and gap between the slits is also 0.2mm. I measured the laser’s minimum spot size. It’s elliptical with major and minor ...
0
votes
0answers
57 views

Young's Double Slit, phase difference and path difference

To produce an interference pattern, the light sources must be coherent right? Coherent by definition means constant phase difference between waves of the same frequency so that means waves can be ...
0
votes
0answers
48 views

Why is a point source required for observing perfect double slit interference?

What would happen with a non-point but coherent source (some kind of ideal flashlight which produces perfectly coherent light for example)?
0
votes
2answers
49 views

To calculate the transmission through a thin film interference structure in multi-layer coating to infinite reflections need to be taken into account?

For a two layer structure shown below I was thinking about the transmission and reflection of light at each interface. As I consider this more and more it seems like there is an infinite number of ...
3
votes
1answer
57 views

Why waves in superposition pass through each other without interference in same medium?

Wave can interact constructively (add up) or destructively (cancel) but how about when they are in a superposition state why is there no interference when they meet up in same medium? Imagine 2 pulses ...
1
vote
2answers
74 views

Why do the two slits of a double slit experiment not make light coherent and create an interference pattern if monochromatic light is passed through? [duplicate]

If a narrow slit makes monochromatic light coherent, why is light required to pass through the single slit before the double slits in Young's experiment? Wouldn't the double slits individually make ...
0
votes
0answers
54 views

White light interference pattern in Newton rings and Fabry-Perot interferometer

I've read that it is possible to obtain Newton rings with white light, seing various rings of different colors, ordered by wavelength. However, in the case of the Fabry-Perot interferometer, it's not ...
3
votes
5answers
148 views

Destructive interference of light and destroying energy?

I've had a hard time with destructive interference of light, and the possibility of destroying energy. I've read countless articles here and elsewhere, leaving me with the answer of something to the ...
0
votes
0answers
42 views

Double slit diffraction

In the intensity pattern of double slit there are two terms one for single slit diffraction $\sin^2a/a^2$ and another is double slit interference $\cos^2b$.In the intensity pattern of double slit ...
1
vote
1answer
28 views

Proof of interference fringes take the same shape as the shape of the film? [closed]

(First of all I should mention time talking about interference between two reflecting rays thinking e.g. Newton's rings.) Studying wave optics I have found that at the fringes take the same shape as ...
1
vote
2answers
115 views

Why gravitational wave stretches on $x$-axis would necessarily compress on the $y$-axis?

I read gravitational wave is a traverse wave, usually produced by inspiraling neutron stars or black holes, and laser interferometer such as LIGO is commonly used to detect them, since the setup of ...
0
votes
0answers
15 views

What frequency range can be tolerated with Young's fringes? (Problem 9.4, Brooker, Modern Optics)

I am having problems with part 2 but provided part 1 for context - I believe I have part 1 correct but could be mistaken. Let a Young-slits apparatus have slits separated by d. Let the incoming light ...
0
votes
0answers
67 views

What is the reason behind diffraction of light?

What is the actual reason behind diffraction of light? I want to know how is the phenomenon diffraction explained theoretically in physics (best if the discussion limits itself to classical physics). ...