Tagged Questions

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 ...

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65 views

Will smoke affect young's double slit experiment

If smoke is present in between the screen and slit in Young's double slit experiment using laser, will there be any change in the interference pattern? Will the fringes be obtained on the screen? ...
3answers
62 views

Bending of light [closed]

Why does bending of light(diffraction) occur?
1answer
68 views

Why does Diffracted Light cone diameter change in relation to angle of light beam?

I have a question about light diffraction. Take a look at these images of the Pantheon oculus. Now what I don't understand, in the first picture, the light is coming in from overhead and forms a ...
1answer
236 views

How to calculate a straight edge diffraction pattern

A straight edge diffraction pattern is not the same as a slit or multiple slit diffraction pattern. The spacing between fringes is not equal but gradually gets smaller the farther out you go as in the ...
0answers
31 views

Wavelength limited resolution

I've read through answers to similar questions, and I haven't been able to find a satisfying answer. I've heard it said that in order to make out something, you need to use light with a wavelength at ...
1answer
155 views

Total number of primary maxima in diffraction grating

I am trying to determine the total number of primary maxima that can be observed when light of wavelength 500 nm is incident normally on a diffraction grating, with the third-order maximum of the ...
0answers
65 views

Single Slit/Double Slit path differences

When diffracting light through a double slit, I understand that the two sources must arrive on the screen m(wavelengths) out of phase [where m is any whole number], in order for a bright fringe to ...
1answer
50 views

Does the wavefront in the double slit experiment represent the electric field of the EM radiation / light?

The question "What is a wavefront?" get the answer "A wavefront is a contiguous region of constant phase". This seems to be right for water waves as well as for electromagnetic radiation. But what is ...
2answers
70 views

Are wave fronts in double-slit experiments moving forward? [closed]

I ask a question about "What is a wavefront?" which follows the question "What makes the radiation behind a slit coherent". For the wavefront it was answered, that "In electromagnetics ...(that are) ...
0answers
91 views

Question about heisenberg uncertainty principle and single-slit diffraction

My question relates to this video illustrating the Heisenberg uncertainty principle. The video shows light being shot through a slit forming a spot on a screen. As the slit narrows, the width of the ...
3answers
102 views

What is a wavefront?

For this picture Anna wrote: "Incandescent light is incoherent because it comes from many sources and the same is true for sunlight. By passing the light through the one slit he created a single ...
4answers
184 views

What makes the radiation behind slits coherent?

Have a look on the sketch To get such a intensity distribution of light behind a slit we presuppose that all the light that moves on the two lines is coherent; of the same wavelength AND the same ...
1answer
43 views

Monochromatic light and interference [duplicate]

What I want to ask is monochromatic light necessary for interference? Doesn't interference occur on just the superposition of two waves(any waves)? And Why don't waves of different wavelengths don't ...
1answer
33 views

Given a light diffracting through an aperture of radius r, how would we find the radius of the beam at a position x meters away?

If we have a light source, say a laser or LED, diffracting through a circular aperture of radius $r$, how would we find the radius of the beam at a position $x$ meters from the optical axis? I ...
1answer
38 views

Wave equation for spatially incoherent light beam

I would like to know what happens to a plane wave from a laser $$\Psi(r)=e^{ikr}$$ after it passes a ground glass. Would I just get a superposition of spherical waves? \Psi(r) = \sum_n\frac{e^{...
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46 views

How does the interaction between individual electrons of beams affects the diffraction pattern?

Consider the diffraction of an electron beam. How does the interaction between individual electrons of beams affects the diffraction pattern? If it really affects the diffraction pattern, then is ...
1answer
84 views

how can interference occur within diffraction?

My book says : The number of interference fringes occuring in the broad diffraction peak depends on the ratio d/a that is the ratio of the distance between the two slits to the width of a slit. In ...
0answers
41 views

Is there sound diffraction grating? [closed]

Sound is also a wave phenomenon. Therefore, is there any counterpart of the usual optical grating for sound?
1answer
68 views

Huygens principle and wave propagation

I have seen the following illustration online and had a brief lecture about Huygens principle. As far as I understood, it suggests that every point in a wavelet acts like a point source to wavelets, ...
1answer
60 views

Differences between single-slit/obstacle diffraction

In class, we have derived the formula for a single slit diffraction (slit length $a$) and it seems that the same equations are used when talking about diffraction around an obstacle of width $a$ (like ...
0answers
44 views

Two-slit experiment, why $\exp(ix)$ and $\exp(-ix)$?

I am looking at an example problem from optics with two narrow slits with light shining through both. The light through one slit is 5 times the amplitude of the light through the other. I know from ...
2answers
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How is the uncertainty principle protected for a single electron diffraction?

In the experiment where electrons are sent one by one through a slit on a screen behind which there is an electron detector, the electron is said to have a definite position at the time it crosses the ...
1answer
44 views

How do atoms scatter X-rays?

I am learning the theory behind X-ray diffraction but I have a question. According to the textbook I am using, X-ray tubes (in diffractometers) produce near monochromatic X-rays. In other words, they ...
0answers
23 views

Diffraction of rays [duplicate]

To all the physics experts here this might sound like a stupid question, but I give it a try: This is a sketch of how you usually learn about the effect of diffraction in an experiment: Now I was ...
4answers
498 views

How can beam divergence be corrected for in a CO2 laser cutter?

I have a 90W RECI CO2 laser tube that I recently measured the beam divergence on. This was done by pointing the laser at a fire brick and melting it for a few seconds at different distances. Multiple ...
1answer
54 views

Optics Diffraction Grating Plot

I was unsure whether to post this in physics stackexchange or mathematica stackexchange, so I posted it in both. I'm trying make an intensity plot for a diffraction grating that contains 100 lines/mm....
0answers
25 views

Diffraction through 1 slit - light levels at minima points are zero or somewhat higher?

During a few diffraction experiments, my partner and I realized that during a 2 slit experiment all minima points surely cannot be completely dark, due to the fact that the two light sources (1 from ...
0answers
17 views

Diffraction grating with film covering half of slits

If I have a film covering part of my slit of finite width is it justified to take the integral of the wave elements with there phase difference as a function of x across each half separately ...
1answer
57 views

Can a magnetic ball “diffract” around a metal object?

Consider a magnetic ball falling through a copper pipe. It falls slower than it would if it wasn't near any copper. We can use this to determine that the closer a magnetic ball is to copper, the ...
0answers
161 views

Is Wikipedia wrong about Huygens-Fresnel Principle?

Someone posted a question about why backward waves don't exist according to the Huygens-Fresnel principle: Why doesn't a backward wave exist? In following up on this question I read the Wikipedia ...
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284 views

Does diffraction take place in Young's double slit experiment?

In diffraction experiments interference takes place along with diffraction? Does diffraction take place in Young's double slit experiment? If it does take place then why don't we get the pattern of ...
2answers
403 views

Difference between Youngs double slit experiment and Double slit diffraction?

Both these experiments have double slits but in one interference takes place and in the other both interference and diffraction. If diffraction takes place in double slit diffraction then it should ...
1answer
45 views

Process of x-ray crystallography

This is a pretty basic question but I would just like some confirmation of what I suspect is true. As I understand it, the basic idea behind x-ray crystallography is that we take our crystal and hit ...
1answer
88 views

In a double slit experiment, fringe separation is constant. However in a diffraction grating fringe separation is not constant. Why is this?

Can you explain this as simply as you can? I am currently in high school and I've been wondering why? Correct me if my question is wrong, and if my assumption in my question is wrong, would you help ...
1answer
52 views

de Broglie's Hypothesis [duplicate]

I've recently understood de Broglie's hypothesis, and I understand that a necessity for electrons to show diffraction is that the size of the aperture they pass through must be of the order of their ...
1answer
78 views

Diffraction pattern in one continuous slit

Will a noticeable diffraction pattern appear if I use a single continuous slit, say a ring shaped one?If yes, can it be explained how the slits were paired for interference observations , and is there ...
2answers
74 views

Confusion in difraction experiments

I had a confusion in the diffraction experiment about which I was taught in school. According to the formula we Derived The width of the central maxima decreases on decreasing width of slit and vice ...
0answers
58 views

Fraunhofer diffraction at circular aperture - integration of bessel function

I'm trying to understand the calculation here: http://en.wikipedia.org/wiki/Fraunhofer_diffraction_(mathematics)#Circular_aperture for the solution by integration, but I plain and simple fail to see ...
1answer
70 views

Energy of neutrons in crystal diffraction

The spacing of the atoms of a crystal is 159 pm. A monoenergetic beam of neutrons directed normally at the surface of the crystal undergoes first order diffraction at an angle of 58° from the normal. ...
1answer
73 views

Why is there no exact formula for position of maxima in single slit interference

On this website (http://www.ualberta.ca/~pogosyan/teaching/PHYS_130/FALL_2010/lectures/lect35/lecture35.html) it says that the formula $\sin(\theta_{max}) = (m+\frac{1}{2})\lambda$ derived for the ...
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63 views

Formula for intensity and central bright fringe in Fraunhoffer diffraction from single slit

I want to understand why, theoretically, the central bright fringe has maximum brightness/intensity. And where does the formula $I=I_0\left(\frac{\sin B/2}{B/2}\right)^2$ come from? My book says it is ...
1answer
176 views

In the double slit experiment with electrons why the single slit case is not diffracting as photons would have?

The famous double slit experiment used in books to describe the duality of particles nature usually presents a case where only one slit is open and there is no diffraction. Aren't we supposed to see ...
2answers
132 views

Single Slit Diffraction

I am trying to derive the intensity variation function for a single slit diffraction. Sorry for the poor diagram... So I decided to take the amplitudes of the waves originating from the slit on the ...
1answer
59 views

does the Fresnel approximation apply in the far field?

Most sources I've looked at treat far field diffraction and near field diffraction as separate cases, with the former using the Fraunhofer approximation and the latter the Fresnel approximation. In ...
0answers
58 views

Is Rayleigh/Wood's anomaly simply the grazing order diffraction?

Is Rayleigh/Wood's anomaly simply the grazing order diffraction? I read some related papers but I am still confused, can I simply understand it as a surface wave propagating on the surface because of ...
0answers
34 views

What are the exact setups to observe a wave function and its collapsed state?

I was reading this article: http://io9.com/5528321/how-smart-do-you-need-to-be-to-collapse-a-wave-function and I need some clarification on the experiment setup. My current understanding is that if ...
2answers
48 views

Diffraction of light

If $l_1$ and $l_2$ are parallel how can they both can hit same spot? Why their difference in path length is $l_2 - l_1 = d \sin \theta$ instead of 0?
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64 views

Source of a parabolic wavefront

The Huygens-Fresnel diffraction integral has been formulated for incident spherical waves. A source of a spherical wave is kind of intuitive, since the perpendicular rays of the sphere converge into a ...
3answers
53 views

In diffraction process, how to describe the edge in the sense of particle-wave duality?

In diffraction experiments photons show behind an edge intensity distributions in the form of fringes. It seems to be without doubt that the edge is a part of the game. My question is, how to describe ...
1answer
114 views

Why light rays gets scattered when it enters a translucent window pane?

Consider the light source is the light post, outside the window of my house (Pic 1). When the rays from the light post enters through the window pane which is translucent gets scattered and forms a ...