How is Abbe's Number Calculated Using Fraunhofer's Lines?

  • Thread starter Thread starter Donchay
  • Start date Start date
  • Tags Tags
    Calculation
Donchay
Messages
10
Reaction score
0
I don't understand how the formula works;

vD= nD-1 / nF-nC

given nD,nF and nC are the Fraunhofer's line with wavelength of 589.3, 486.13, and 656.27 respectively in nm.

Now my trouble starts here. Since the wavelengths are already given , VD is always a constant. How does the relationship between wavelength and refractive index goes here? Say if I want to measure a random value of refractive index/wavelength of a glass, how do I put the refractive index of my glass into the above equation?
 
Physics news on Phys.org
Abbe's number is indeed a constant, which is characteristic for each glass. It tells you whether a glass has a high or a low dispersion.
To answer your questions it would be helpful to know what you really are trying to do with the refractive indices.
 
DrDu

I'm working on a university project to find the the optical property of a kind of glass. One of the property I'm doing research on is the dispersion of the glass, and therefore I will be looking into it's Abbe number. I have done the test on refractive index and obtain some data experimentally.

How should I use the refractive index i obtain experimentally to calculate Abbe's number of my kind of glass, since I don't know where to fit in my refractive index into that formula?

I was thinking about to start using the Cauchy dispersion formula, which you have seen on my previous post. By finding the constants A, B and C, I can then plug in the wavelength of the Fraunhofer values and obtain the refractive index of the Fraunhofer values. Can it work? Or is this the way it should work?

Thank you.
 
Yes, this sounds very reasonable.
 
From the BCS theory of superconductivity is well known that the superfluid density smoothly decreases with increasing temperature. Annihilated superfluid carriers become normal and lose their momenta on lattice atoms. So if we induce a persistent supercurrent in a ring below Tc and after that slowly increase the temperature, we must observe a decrease in the actual supercurrent, because the density of electron pairs and total supercurrent momentum decrease. However, this supercurrent...
Hi. I have got question as in title. How can idea of instantaneous dipole moment for atoms like, for example hydrogen be consistent with idea of orbitals? At my level of knowledge London dispersion forces are derived taking into account Bohr model of atom. But we know today that this model is not correct. If it would be correct I understand that at each time electron is at some point at radius at some angle and there is dipole moment at this time from nucleus to electron at orbit. But how...
Back
Top