Diffraction Definition and 1000 Threads

I'm supposed to give a seminar tomorrow for my 300 level experimental physics paper. The experiments we do our reports on are pre-determined and I pulled the short straw with the most bloody complicated on here, the acousto-optic modulator. I'm trying to get my head around it and I've spend the...

What does a diffraction grating do, and what is it used for? Are there circumstances under which light must be considered a particle? When? From wikipedia, diffraction grating is an optical component with a periodic structure, which splits and diffracts light into several beams traveling in...

Homework Statement A double slit experiment is set up using a helium-neon laser (wavelength 633 nm). Suppose we add a small piece of glass (n = 1.50) over one of the slits. Then, the central point on the screen is occupied by what had been the m = 10 dark fringe. Determine the thickness t of...

Homework Statement Hey everyone. Just as a preface so you all know, I'm in England studying AQA Physics A. I'm currently studying the optional astrophysics module. I have a problem - in all the textbooks and revision guides I have, there is a topic on diffraction of light through a grating...

Just a question about the naming of optical phenomena. I've taken these explanations from a book I'm using: Diffraction is when a single wave passes a slit or obstacle and spreads out. The single wave produces a diffraction pattern. Interference is when we have more than one source of...

After searching on the web and reading a bit, I found that lenses can perform Fourier transform. All you need to do is put a transparant object in front of it, like a transparant sheet with black stripes on it and a screen behind the lens(so basically a 4f setup). The lens will then perform a...

I know that a smaller width of a gap would lead to "more diffraction", and diffraction effects are at their peak when the wavelength of the diffracted waves is equal to the gap width. But what if the gap were smaller than the wavelength? Can someone describe the diffraction pattern (if any) that...

Hi, I was wondering how you can calculate the intensity of light produced by diffraction orders. If say a laser was incident on a diffraction grating and this split the zeroth and +-1 orders what percentage of the light intensity is within the zero and first orders and how can you work this...

What is the concept behind Diffraction, "n", Finding Dark/Bright Spots I used the following youtube video to help me learn about the concept of diffraction but still could not make sense of my lecture notes: (All 4 parts) SINGLE SLIT DIFFRACTION In order to find the minima the following...

Can diffraction be explained for tilted light arrays or only normal incident lights can have diffraction orders?

I seem to not be able to differentiate between the two of these phenomenons. Please give me some example in daily life to show the difference between them.

Homework Statement Visible light passes through a diffraction grating that has 900 slits per centimeter, and the interference pattern is observed on a screen that is 2.58m from the grating. In the first-order spectrum, maxima for two different wavelengths are separated on the screen by 3.16...

If I send a single wave toward a corner won't it bend around the corner? If so, how does the wavelength of that single wave (is wavelength defined for a single wave?) effect how much it bends? Every picture/illustration I have found on diffraction shows a series of lines (plane waves)...

Hi, I have read that light could either behave as waves or particles but not both at the same time. What will happen if we perform the diffraction experiment, but replace the screen with a metal whose work function is small enough so electrons could be ejected from the metal? Do we see...

Homework Statement A beam of positrons (positron ≡ antielectron) travels at 0.001% the speed of light and impinges on a slit that is 1 μm wide. Use modern units to find the angle θ between the center line and 3rd minimum of the resulting diffraction pattern. How far away (in cm) would you...

Hello, I have to do an experiment in which I will investigate the diffraction grating of a CD and a DVD. I want to find out the spacing of tracks on both of them and thus find how much information can be stored. Also I want to compare them (density of tracks etc.) and maybe even suggest...

Homework Statement Is it necessary that a single slit diffraction occur with the two source having the distance of \frac{a}{2}?Are there any diffractions occur when the point source having the distance of \frac{a}{3},\frac{a}{4} and so on? And I would like to know whether are there only...

Hello. 2 questions: 1. If a diffraction grating is smaller, approaching infinitely smaller, than the wavelength of incident light, what happens to the diffraction pattern? Does the wave still diffract at all? 2. Wavelength is the distance between two crests of periodic motion. Imagine...

why should we use a convex lens to focus the rays at the point on the screen.why is at an angle instead of being straight?

I was reading the Princeton Review AP Physics B book and i don't understand the concept of diffraction. Can someone please explain it to me?

I've read that if you want light to diffract through a single slit, the slit opening must be equal too or less than the wavelength of the light. So for example, light of wavelength 600nm would diffract through a slit with width 600nm or less. Is this true? Or am I missing something. Since when I...

Homework Statement Light from infinity strikes a diffracting grating normally with 600 lines per mm. The emitted light then passes through a lens to project visible light (400-800 nm) spectrum onto a screen that is 50mm, just enough to cover it. Find the focal length of the lens. Homework...

Homework Statement It's got a diagram in it so I have just attached a picture of it. Homework Equations nλ=2dsinθ The Attempt at a Solution I've really got no idea how to proceed with this one. I think you have to consider the effect of the thin film as well. Any ideas?

Homework Statement A system of 8 slits, each separated from its neighbour by 0.05 mm, is illuminated with light of wavelength 576 nm. Using phasor analysis, evaluate at what angle on a distant screen there is the first minimum in intensity. Homework Equations The Attempt at a Solution Ok...

Diffraction on 1D grating is covered in many physics books. Usually they cover simple case when incident light is coming along the normal to the grating. Sometimes they present slightly more complicated case when incident light is tilted in the plane perpendicular to the stripes (left case on...

Bragg diffraction - How to make sense of it ?? Is there a way to make sense of Diffraction of X Rays without taking recourse to oversimplified concepts like "Reflection of X Rays by parallel planes" which is generally the explanation in most basic physics books. It's been a couple years since I...

Hi, I have tried to understand powder diffraction "spectrum". What I do understand is that those diffraction peaks are peaks from ewalds sphere. What I don't understand is how one can get planes and (3d) base vectors out of that. I would really appreciate some help?

Hi all, This is probably an error resulting from my qualitative understanding of diffraction, but in most basic descriptions of the phenomena they talk about diffraction occurring when light encounters an aperture that is equal to or smaller than the wavelength of the incident light with...

Hi Guys, I assume you are familiar with the equations so i do not post them (please write if u want me to post them). One of the steps to prove Kirchhoff's diffraction equation is to use Green's second identity. This identity shows the relation between the solutions in the volume and...

Why does the size of an obstacle have to be comparable to the wavelength of radiation for diffraction effects to be noticable ? Secondly, if the size of an opening is much smaller than the wavelength of the radiation , how does the radiation interact with the opening ? Third, can the same things...

Homework Statement Visible light passing through a circular hole forms a diffraction disc of radius 0.1mm on a screen. If X-ray is passed through the same set up, what will happen to the radius of diffraction disc? The Attempt at a Solution I'm really clueless regarding this question. I...

In x-ray diffraction , even though its reflection is happening , we call this as x ray diffraction. why is it so?? i don't know whether it has been discussed previously here.

(A) What kind of pattern of would you get if you shone monochromatic light on a diffraction grating? What pattern of light would you get if you shone white light on a diffraction grating? My answer: With monochromatic light, you would get a pattern of alternating light and dark bands. With...

Homework Statement microwave of wavelength 3 are incident to a row of parallel metal rods. The separation of the rods is 10cm. The first order diffraction is observed at 25° to the direction of the incident wave. Determine the angle between the first and the second order of diffraction maxima...

Homework Statement 1. From conservation of energy point of view if single and double slits, and diffraction grating had slits of same width, how should their overall light intestines compare 2. under what conditions can we consider double-slits intensities as approximately constant...

I'm currently in a modern physics class and one of our labs was an electron scattering experiment that required the use of a cathode ray tube and a target foil. We aim the electron beam through one of four quadrants on the target foil and measure the diameter of the ring diffraction pattern...

So my teacher regularly makes mistakes on his powerpoints and this is leaving me feeling uncertain about something he has posted. We are studying the Heisenberg uncertainty principle and discussing a situation in which an electron beam is being fired in the x direction at a small slit (length...

Homework Statement Describe how the Fraunhofer diffraction pattern of a grating depends on: (a) the spacing between the grating lines; (b) the overall extent of the grating; (c) the amplitude distribution over an individual line; (d) the phase distribution over an individual line. A...

[b]1. Two towers built on hills are 50 km apart and the line joining those passes above a hill midway between them. what is the longest wavelength of radio waves which can be sent between the towers without serious diffraction effects caused by the central hill? [b]2. Is the width of the...

I was wondering if diffraction of a wave can occur when the gap through which the wave passes is shorter than the wavelength itself. Then I came across this website http://www.talktalk.co.uk/reference/encyclopaedia/hutchinson/m0015966.html Which says that "In order for this effect to be...

I did an experiment where a red laser went through a diffraction grating The distance between the diffraction grating to the screen is 10cm (x) Later I measure the distance from the central dot to the first dot (4.5cm) (y) after this I measure the distance from the central dot to the second...

Homework Statement A single slit forms a diffraction pattern with monochromatic light. The 4th minimum of the pattern occurs at an angle of 35 degrees from the central maximum. How many bright bands are on each side of the central maximum?Homework Equations Number of minimum brightness bands =...

Homework Statement I wasn't sure where to post this question. I hope I picked the right section of the forums. This is from intermediate lab. The lab is for Bragg diffraction using microwaves. The grazing angle is a measured quantity along with the voltage (which was measured using an...

Is it the same thing as Bragg diffraction, in the sense that it is caused by the photons being scattered in different directions when it hits the atoms of the solid material around the slit?

Homework Statement Show that the equation mλ=dsinθ becomes mλ=d[ sin(θ-κ) + sin(κ) ] when the light is incident on the diffraction grating at an angle κ to the normal. Homework Equations The Attempt at a Solution I am not quite sure of the answer (we are just learning this in...

Homework Statement If light incident on a diffraction grating makes an angle η with respect to the normal of the grating, show that mλ=dsinθ becomes d( sin(θ-η) + sin(η) ) = mλ Homework Equations The Attempt at a Solution I haven't done any work with diffraction gratings in a...

Homework Statement You want to photograph a circular diffraction pattern whose central maximum has a diameter of 1.2cm . You have a helium-neon laser (λ=633nm) and a 0.13-mm-diameter pinhole. How far behind the pinhole should you place the viewing screen? Homework Equations Y = λx/b...

diffraction -- how does it actually work? In diffraction for light of a single slit, i know that a bright spot appears in the center and subsidiary bright spots to the sides of the central one, but I have a hard time explaining how diffraction works. I need some help coming to a satisfactory...

Can somebody explain to me what is the difference between double slit diffraction and double slit interference?, to me they are the same thing but my teacher says they have two different meanings, thanks.

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