Permeability of Light: Dependence Factors

[mustaffarel]

What does a substance's permeability of light depend on?

 

[Integral]

The permeability of free space,or the permeability of a substance, is the parameter that determines how the substance effects a magnetic field. It does not just apply to light but to all magnetic fields

 

[mustaffarel]

Is it because of visible light is a kind of electromagnetic wave?

 

[kirovman]

Visible light is only a small part of the Electromagnetic wave spectrum, ranging from radio waves, up to X-rays and Gamma Rays, with visible light somewhere in the middle of the scale.

The parameter \mu_o is the permeability of free space.
\mu_r is the relative permeability (analogous to \epsilon_r)

It can be defined as B=\mu_0 (H+M)

Where B is the magentic induction field, H is the magnetic field strength and M is the magnetisation across the sample.
or with some working:

B = \mu_0 \mu_r H

Since M = \chi_m H
and \mu_r = (1+\chi_m)
(\chi_m is magnetic susceptibility)
relative permeability in a material is just some kind of a measure of how much of an applied magnetic field will be "used up" due to magnetisation in the material.

Also it is said that B is what you pay for, H is what you get.