Refractive index Definition and 280 Threads

Newtons Rings Calculations - Values Not Working Out I'm having trouble with a Newtons Rings experiment to determine the refractive index of water. I'm using a sodium light source and a Vernier scale traveling microscope to measure the radius of the bright circles (I don't know if measuring the...

Imagine a dielectric made of of alternating layers of widths A and B and refractive indices (a*) and (b*). Find the effective refractive index, N So in general: c/n = wavelength x frequency = phase speed My thinking was find the total time taken for the wave to propagate through the...

Hi, I have read on a website that the refractive index of glass is related to the number of electrons it has per unit volume. I don't recall which website it was, but is it true? & if so what is the quantitative description behind it? or is it a lot more complicated :) Many thanks for...

What is the refractive index for silicon ?

Homework Statement I know that in free space, the width of a Gaussian beam can be written as W=W_0\sqrt{1+(\frac{z}{z_0})^{2}}. However, I was wondering if it was possible to express this width as a function of refractive index instead (since I don't believe a Gaussian beam originating in say...

Homework Statement I need to find the refractive indexes of the core and cladding of an optical fibre by using the specs found here http://www.photonics.byu.edu/FiberOpticConnectors.parts/images/smf28.pdf Then I'm suppose to calculate the Numerical aperture and compare it with the one listed...

Hi, Got a problem with the following derivation: Coming from the Helmholtz equation one gets: \textbf{n}^2=\muc^{2}(\epsilon+i\frac{\sigma}{\omega}) which is of course something like: \textbf{n}=n+i\kappa My question is, how do you obtain the following relations...

Homework Statement The interference pattern formed is given by I(θ)=4I0cos2(∏dsin(θ)/λ). For d=1×10-5m and λ=500nm plot the intensity pattern as a function of θ for small θ. How would this change if a block of material of thickness 500nm and refractive index n=1.5 were placed over one slit...

I was studying Rayleigh Scattering. The theory says that Rayleigh Scattering is approximated to x<<1 where x=(2*pi*r)/lambda where r is the radius of the particle scattering light and lambda is relative scattering wavelength of light. lambda = wavelength of light / refractive index of...

Dear All, thank you for taking the time to view my post. I am a Biologist and I have come across a curious characteristic of proteins that are structural constituents of Nerve cell sheaths (These proteins in addition to lipids surround nerve axons). In general, they seem to have a high...

Not sure if one exists but can anyone point me in the right direction? Looking for a formula which includes the temperature and partial/total pressure dependencies? I'm trying to find the trajectory of a photon through a cloud of varying (but known) temperature, pressure and humidity. If...

or is it possible to create a material with very high refractive index(order of 100's or more)

For a wave traveling from a medium with refractive index n1 to n2 with n2 > n1, the amplitude reflection coefficient is given by: r = (n2 - n1)/(n2 + n1) Consider a beam of light passing through a single pane of glass. There is a reflection at the front surface of the pane, with the...

Hi Folks, After a general search online, I have not yet found a simple description of refraction in a medium with an inhomogeneous refractive index. For example: if we have a block of glass with a beam of light shining through it, and the block has a gradient in the real part of the...

Hi all, I am thinking about the refractive index, if I have two components with refractive index n1 and n2, respectively, then I mix them up (chemical reactions might happen after the mixing), and should I expect a mixture with refractive index:n=a*n1 + b*n2, where a+b=1. In other words...

Homework Statement At a wavelength of 400nm, the semiconductor ZnSe has a complex refractive index n= 3.0+0.32i A) If 400nm is incidient from air onto ZnSe with θ=tan-1(NR) = 71.6°, What is the refraction angle of the transmitted wave? B) Calculate the magnitude R and phase shift ψ...

How can i calculate the refractive index knowing only the frequency of the light entering the medium from air? n(refractive index) = (speed of light in vacuum) / (speed of light in medium)

Question: A Fsherman sees a Fish in a river at an apparent depth below the surface of the water of 0.75 m. Given that the refractive index of water is 1.33, is the true depth of the Fish below the water's surface: A 0.75 m? B Less than 0.75 m? C 1 m? D More than 1 m? My proposal...

Hi all, I'm looking for an equation which will give me the focal length of a biconvex lens given that we know both Radii of curvature, the thickness of the lens and the refractive index inside and outside. An equation is given on wikipedia here http://en.wikipedia.org/wiki/Focal_length as I...

Homework Statement Hey guys, new to the forums so hopefully you can help. I have been given the frequency (and hence the wavelength) of a microwave of 10GHz, and the conductivity of Al which is 3.53x10^7 Siemens/m. From this I have worked out the skin depth. But it asks also what the...

we can calculate the refractive index of liquids like water using a converging lens and mirror by the standard method . r.index of water is less than that of lens(glass) . now taking mercury, whose r.index is > glass, can we do the same experiment and find its r.index ? i believe the answer...

Homework Statement "Calculate the reflection loss when a beam of radiant energy passes through an empty quartz cell assuming the refractive index of quartz is 1.55"Homework Equations I/I_i = ((n2-n1) / (n2+n1))^2The Attempt at a SolutionI'm taking the refractive index through the empty cell...

I recently came across the representation of n(ω) for refractive indices. I also scouted the internet for explanations but could find none, except one on 'complex refractive index' but I don't think that's quite it. So how exactly is refractive index a function of frequency?

My textbook says it has been proven that the refractive index of a medium is a ratio between the speed of light in air or vacuum and the speed of light in a medium. It says that the ratio is the same as sini/ sinr . But isnt't it the inverse? And, can someone please explain this law to me In...

1. The refractive index of the Earth’s atmosphere is n = 1.01 + α(R − r), where α is a constant, r is the radial distance from the Earth’s centre and R = 6.4 × 10^6 m is the Earth’s radius. By considering a path comprising a series of total internal reflections or otherwise, find a value of α...

Part A i just need to know if i have done it properly. Part B is done Part c don't have a clue :cry: Homework Statement Homework Equations Law of refraction n1*sinχ1=n2*sinχ2 Critical Angle sine(x) = nr/ni The Attempt at a Solution part a is on the image above part b I have done it...

hi, i have seen on another topic here that the refractive index equals the square root of the dielectric constant. from datasheet values we have... water refractive index = 1.333 dielectric constant = 80.1 Without even doing the calculation its obvious that the square root of 80.1 is not...

Hi Some of my students are doing an experiment, investigating the refractive index of different liquids such as water, alcohol, syrup (very concentrated sugar solution!), and oil. The results that of their experiments seem to be showing that oil has a high refractive index than water and...

What is the relationship (a mathematical one) between the density and the refractive index of a medium?

Homework Statement Attached as pdf. Homework Equations Attached as pdf. The Attempt at a Solution I know that refractive index is given by n=\sqrt{\varepsilon} normally. But is it still the case when asked for n( \omega) ? If so, I've tried rearranging equation 3 for...

[SOLVED] I have got the answer. Answer is 40cm. --------- Homework Statement Focal length of thin lens in air is 10 cm.now medium of one side of lens is replaced by medium of refractive index μ=2.the radius of curvature of lens with contact with the medium is 20cm. Find the new focal...

Situations that Require the Accurate Determination of Refractive Index

why do refractive index vary with the wavelength?what makes the relation between wavelength and the refractive index reverse relation??and what makes the relation between frequency and wave length direct relation??does it has somethin to do with energy and the abiliy to penetrate bodies??Are...

Hi ... my equations is : 1- if the refractive index of the dielectric material related with frequency ? if yes , is that because the permittivity relation with frequency or permeability or both of them ?. also i want the equation of refractive index relation with frequency. 2- in...

what does refractive index depend upon? The answer of my textbook is "wavelength" so how,although it cannot be controlled directly?? I thought It depends on the speed of light in the media I don't understand how to answer these kinds of questions for example :what does the deviation angle...

[PLAIN]http://img843.imageshack.us/img843/6831/dsc00723mm.jpg a light ray falls on parallel layers made of transparent materials which have different refractive indicies so ,what does the ratio sin(fi 1)/sin(theta 4) depend on? 1-n1,n2 2-n2,n3.n4 3-n1,n2,n3,n4,n5 4-n1,n2 could you...

http://www.fiberoptics4sale.com/Merchant2/fofs_img/how-optical-fiber-works.gif The refractive index of the core is higher than that of the cladding, I don't understand why!

I have a plastic disk 0.5" in diameter whose radius of refraction is supposedly non-uniform. It will vary by 0.015 at most from the center to the outside. I need to come up with some method of measuring the refractive index locally. I have access to: helium neon laser a photodetector and...

whats the relationship between the temperature of water and its refractive index?

I am modelling a radio wave propagation simulator for a Wifi at 2.4 Ghz. I know that the refracted index of glass for light is around 1.5, how do I translate this to a 2.4 Ghz radio wave. And what about other materials, such as concrete, brick wall etc. Thanks.

Homework Statement The conductivity of a plasma is defined as \sigma = i\frac{Ne^{2}}{m\omega} where N is the electron density. a) Prove the refractive index is: n = \sqrt{1- (\frac{\omega}{\omega_{p}})^{2}} with \omega_{p} = \sqrt{\frac{Ne^{2}}{m\epsilon_{0}}} b) Show the Attenuation...

Homework Statement a ray of light traveling through glass is incident at the interface with air at an angle of 30 deg to the normal. if the ray is refracted at the critical angle, what is the refractive index of the glass? Homework Equations none The Attempt at a Solution sin...

Refractive index is defined as n = speed of light in a vacuum / speed of light in medium Since both speed of light in a vacuum and speed of light in medium are real number, refractive index also has to be real. But we know that in general refractive index is complex. So what actually is...

Homework Statement Problem: Sea water has k = 80 in the low frequency limit. Yet its refractive index is around 1.34. Explain the discrepancy Homework Equations For a non magnetic dielectric medium, the absolute refractive index in the low frequency range, is given by : n = √k...

I would like to ask a few questions. Does a table of refractive indices of materials at rf frequencies (say for TV) exists? Is there a way for me to estimate it for some materials? Are the refractive indices of these materials higher? Will those materials have low absorption losses at these...

Homework Statement Let’s say you have a transparent crystal sphere, on the far side you cast colored glass. By choosing the right refraction index, the image of glass corn would appear located at infinity (when you look from the other not colored side). Suggest a refraction index...

This is for my 1st year undergrad course but it feels quite basic and not worthy of the 'Advanced Physics' section. Yet there's one thing I'm confused about - I have the answer, just something I don't understand. Homework Statement Light falls normally on a glass surface. What fraction of the...

Homework Statement Using your knowledge of perpendicularity between the reflected and refracted rays at the polarising angle, find brewster's law, a relation between Io (the angle to the normal) and the refractive index n. The relation consists of no other variable or physical constant No...

Variations in Refractive Index of atmosphere with altitude ?? The queries i have are related to refraction of light. 1. How does the refractive index of air vary with the altitude ? If possible explain the reason for change. 2. Does the amplitude of a wave change during refraction?

I'm just wondering how it works exactly? How can a solid submersed in a liquid somewhat "disappear". I've tried googling it with no luck and I'm super intrigued by this whole concept. PS: the more clear and simple you can explain it, the better.. I tend to get confused easily by things like this.