Dispersion Definition and 284 Threads

I know acoustic and optical phonons can interact with one another. Also, longitudinal and transverse phonons can interact with one another. I am wondering can a longitudinal phonon in one plane act with a transverse phonon from another plane to create a third phonon? Or, do these...

Anomalous Dispersion? All I know about anomalous dispersion is that it has a negative second order propagation vector. That would mean the refractive index is negative...how? How do you also "achieve" or get "into" the anomalous dispersion regime?

I am trying to understand 3D Si dispersion relations and reciprocal lattice vectors. My confusion is that when I look at dispersion relations the wave vector typically is normalized from 0 to 1 by a/2pi. I thought the edge of the first BZ was pi/a. Is this correct or is it 2pi/a for a diamond...

In dispersion relation diagrams, where omega is plotted against k, omega is sometimes nonzero at k=0. How is this possible? I thought a wave had to have a nonzero wavenumber :confused:

Hi all. I am referring to the Kdv equtaion as follows: u_t = u u_x + u_(xxx) A fundamental point concerning the KdV equation is that it exhibits two opposing tendencies: 1. "nonlinear convection", uu_x, which tends to -steepen- wavecrests, 2. "dispersion", u_(xxx), which tends to...

Homework Statement Yellow light strikes a diamond at a 47.0° angle of incidence and is refracted when it enters the diamond. Blue light strikes a piece of flint glass and has the same angle of refraction as does the yellow light in the diamond. See Table 26.2 for data. What is the angle of...

Hi, I have a question about the dispersion of white light in prism. Why different color of light have different speed in prism ? What properties of light affect its speed ?

My chemistry textbook states the following: "In general, larger molecules tend to have greater polarizabilities because they have a greater number of electrons and their electrons are farther from the nuclei. The strength of the dispersion forces, therefore, tends to increase with increasing...

hey guys, I'm currently doing a project on laser beam, and just wondering what material i can use to disperse a laser beam so it hit a surface with more surface area. thx Dazza

For those of you who are interested in learning about air pollution dispersion modeling, I recommend that you read the following online articles at Wikipedia: Atmospheric dispersion modeling Air pollution dispersion modeling books Air pollution dispersion terminology Compilation of air...

-Let's suppose we have 2 gases ..one is a "Fermi" gas under an Harmonic potential and the other is a "Bose" gas under another Harmonic potential... in both cases (as an approximation) the particles (bosons and electrons are Non-interacting) then we could write the partition functions. \prod...

Can weever have disperdion of a wavegroup with a unique frequency?

hello Here I a prism with a visible light striking it at 45degree to the normal and the prism has an apex angle of 55.7 degree. It disperse Red, Orange, Yellow, Green, Blue, and Violet color in that order with 1.66 for violet light index of fraction and 1.61 for Red light. I have figured...

I'm studying the phenemenon of band gaps in a experiment, however the stop bands are proving hard to define using just a transmission spectrum dervived from the fft alogrithm. I've heard that it may be possible to define the band region by plotting the dispersion relation of sound waves the...

Hello, I was wondering if someone more knowledgeable in loop-quantum gravity or string theory could discuss a bit about the following topic for me: If there is a lower size limit (or length itself is quantized), does this (or can this) mean that there would be a dispersion relation for light...

Dispersion relations have the tendency to confuse me. In general, I know what dispersion is, but trying to apply it to crystals, I just "can't see the forest among all those trees". :rolleyes: In phonon dispersion, acoustical and optical phonons have quite a different dispersion behaviour...

i need to know what r normal and anamolous dispersion?

what is meant by dispersion in a wave?

i'm getting confused. so when white light diffracts, red light will bend the most and blue light will bend the least. but when white light disperses, blue light will bend the most, but white light will bend the least? I'm not understanding why. and also i read somewhere that the angle of...

(a) A narrow beam of light containing yellow (660nm) and green (550nm) wavelengths goes from polystyrene to air, striking the surface at a 30 degree incident angle. What is the angle between the colors when they emerge? (b) How far would they have to travel to be separated by 1.00 mm? I need...

I need help with a problem in solid state physics: Find the dispersion relation of long-wavelength plasmons in a simple tetragonal crystal in the case of almost empty band built of s-type orbitals. What happens in the case when m_{xx} << m_{zz} ? This is what I did for now (with some help...

Hi, please could someone explain the term dispersion relation to me, particularly for the case of a free electron? Thanks Jayse

Hi I'm studying for a test, and in the suggested reading book review has a few equations that they talk about but I'm not don't really understand how it jumps from one thing to another? the book is very vauge... I've broken the parts i don't understand into A,B,C (I used w = omega) A)IT shows...

Hi I'm studying for a test, and in the suggested reading book review has a few equations that they talk about but I'm not don't really understand how it jumps from one thing to another? the book is very vauge... I've broken the parts i don't understand into A,B,C (I used w = omega) A)IT shows...

I'm having extreme difficulties finding understandable informations on the why and how on the topic of wave paquets, dispersion, phase and group velocity. My question is this. The motion of waves of small wavelenght at the surface of water is governed by the surface tension. The phase...

I feel rather stupid for not understanding this, but it's really thrown me for a loop, so any help would be greatly appreciated! A ray of light is incident at 45 degrees on an equilateral glass prism (n=1.5). So far, I have determined the angle of refraction to be 28.135 degrees, using...

This question bothered me for some time. From what i have seen in textbooks, dispersion occurs as soon as white light passes from air into a glass prism, but why not for a glass block, assuming that the angle of incidence is the same? The standard answer for why dispersion happens in glass...

I would like to understand a little more about the low waters and high waters observed during a tsunami. My first understanding was that the bottom of the ocean collapsed by a few meters in a 500 km² region in front of Sumatra. I could then understand low waters on the coasts. However, I...

Are they the same? Is dispersion only to do with light waves & diffraction for all waves?

So here are my questions If z(w)= R + iw/c, then 1/z = 1/(R + iw/c) Where does 1/z have singularities? I mean, there doesn't appear to be a point where R= -iw/c since R is real and the other term is imaginary. And how do I show the Real and Imaginary parts of 1/z are related by...

I'm confused on this question. I would show my work, but I'm not sure on how to even approach the question. The book labels this problem as straight forward, but I still don't see it and I'm confused on which formula(s) to use.. A narrow white light beam is incident on a block of fused...

Hi all. I'd like to ask why an achromatic doublet (one concave & and one convex lens of the same curvature cemented together) reduces chromatic abberation. Do any of you guys know how and why it does this (reduces chromatic abberation)? Thank you. Just for your info: Chromatic abberation...

Can anyone provide me with information on dispersion diagrams. I am trying to understand how to read/creat them.

I have read that the interference patterns on a piece of holographic film can be cut, and any segment that is cut out will display the entire hologram when a laser is used to produce an image. By this I mean if you take a piece of holographic film and cut out any portion of it, that portion, no...