Refractive index Definition and 280 Threads

(I'm still reading the QED book by Feynman...) What property of the material causes a specific refractive index for a particular medium? (in other words, from the FAQ section by ZapperZ, "So the lattice does not absorb this photon and it is re-emitted but with a very slight delay.". How is...

Hi, this is the question in my homework. Explain what happens when a light ray enters and leaves a glass block if it hits the face of the block at right angles to it. Can someone pelase help me, i think that the light ray would just go straight through the block without bending but I am...

The index of refraction is a complex number if the mediums conductivity is non zero. n=Re(n)+Im(n)*i We know that for real refractive index: v=c/n How is the corresponding relation for complex n? I would expect (and got from my calculations) v=c/Re(n), but since Re(n) may...

Normal glasses have a larger refractive index for blue than for red. Are there special glasses that differ in this respect? Or maybe are there some minerals that behave differently, still being transparent in the visible spectrum and colorless? Thanks to tell me if you know something about...

I was reading this article http://news.bbc.co.uk/2/hi/science/nature/841690.stm I don't understand how this doesn't defie relativity. It sais something about you can see the light exit the caesium before it even enters, thus having went faster then the speed of light but the article sais it...

The Maxwell's relation in electromagnetic theory states that refractive index is equal to the square root over the di-electric constant. This relation holds for some simple gases.But more generally,it does not.My question is why this is the case. Eugene Hecht says that this is because n...

How close do two refractive indices, e.g. a liquid and solid, have to be for the solid in the liquid to be invisible to the naked eye? 1st decimal place, 2nd decimal place?

Is there a general formula to calculate the refractive index of a mixture of two liquids of known refractive index, e.g. water and ethanol, or water and glycerol?

I'm puzzled (as usual). The Kramers Kronig transform is commonly used to relate real and imaginary components of the electric susceptibility- \chi(\omega) It appears from reading papers that it also works for relating real and imaginary components of the refractive index. But why? That...

The problem is described here: http://phstudy.technion.ac.il/~wn117066/Problems2.pdf In question 1 I need to find the refractive indices for both polarizations at 760nm. I'm not quite sure how to go about this - which model of dispersion best fits Calomel? (I'm done with the exercise...

Hi I have just conducted the experimental stage of a practical 'to find the refractive index of different objects using Snell’s law' (which states sine i/sine r =N). The objects chosen were Ice, Glass, and Perspex. As 3 trials were taken for all 3 objects, if these points were graphed, and a...

I am doing my homework and i come across a question. What is the SI unit for refractive index?All my revision books did not have the answer.Or perhaps the book is wrong by any chance?

This is from my Physics practical experiments. The experiment is to find the refractive power of the prism for different colours and also to determine the dispersive power of the material of the prism. My question is how does the refractive index of the material of the prism vary with the...

hi i've got to do measure hte refractive index of a liquid with mirror and lens first of all how can i measure hte refractive index of air in this way? i don't get how i can do this, please explain :| and then for the liquid, I've been told to put the liquid over the mirror and then the...

I want to measure the refractive index of a thin cantilever ; however the sample is too small (about tens of microns). on the other hand, the cantilever maybe not flat at all and it is curly. how can I do it?

We know,n=(rel.permittivityxrel.permeability)^(1/2) For natural transperant mediums (to visible light of EM spectrum)are non-magnetic.So, rel.permeability=1 hence n=(dielectric constant)^(1/2)...

Here is the question: A factory uses a beam of light to allow workers to visually check the temperature of a liquid. A semi-circular crown glass (refractive index (n) =1.75) block is placed in a liquid X whose refractive index n changes with temperature T (in °C) according to the formula: n =...

Let n denote the refractive index of water. What fraction of the speed of the light in air is the speed of underwater light? Let \theta denote the critical angle for light going from water to air. Find the value of sin \theta.

Can someone please help me out? I was wondering whether or not there is a solid (i'm thinking a form of silicon) That is transparent and when an electric charge of some kind is passed through it it's refractive index changes There was an article in new scientist about this along time ago...

Wkipedia gives refractive index n^2 = (Relative Permittivity) x (Relative Permeability) but taking water as an example n = 1.33 Relative Permeability = 1.0 (roughly) Relative Permittivity = 80.4 1.33^2 = 1.77 Which is NOT 80.4 what's wrong?

Dear all, i am a bit confused with a very simple equation connecting refractive index of water and its dielectric constant for visible range of wavelengths and room temperature. i hope, You can help me as we know, the refractive index 'n' can be defined as n=sqrt(epsilon*mu)...

Can anyone show me a proof of "refractive index= (real depth)\(apparent depth) "? I found the proof in my book has a mistakes and I found some contradicts to this equation.

Hello, I'm a bit stumped on a problem and wondered if anyone knew how to approach this problem: When a Newton's ring apparatus, ( Fig. 24-30(see attached) ) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.99 cm to 2.49 cm. What is the refractive index of the...

What are the properties of materials havind negative refractive index? Are they theoretical or do they exist?

ok I've been wondering about this for awhile when people say the speed of light slows down when going through an object (ie glass). does the speed of light actually slow down to 2x10^8 m/s or does the speed of light actually stay constant at 3x10^8, but the photons collide with the SiO...

The equation relating these is : sine(critical angle) = refractive index between 2 meterials. Could someone please supply a proof for this? Also, as a side question :wink: , is there a proof for the sin i / sin r = v1/ v2 , not including the one in which you draw triangles and...

Negative Refractive index! Is negative refractive index possible(theoretically,in optics). If so what are its implications? :smile:

Light ray goes into a container at 70 degrees, the container is made of perspects. The refective index of perspex is 1.48. What are the angles of refraction in (i) the water; (ii) the plastic, (iii) the air below the tank. I can't work it out, the answer to the first bit is 26 degrees, i...

I have a transparent silicone model flow chamber which I would like to use for flow visualisation studies. Ideally I would like a fluid whose refractive index is the same as the silicone, hence minimising distortion of the field of view. The refractive index of the silicone model is approx 1.4...

The Question: A 45-45-90 prism is immersed in water. What is the minimum index or fefraction the prism must have if it is to reflect totaly a ray incident normally on one of its faces. Now, we have found this question a bit hard to understand. We assume that light is hitting one of the...