Communication Needs

Is a material with a high refractive index better for fibre optics ?

If so why ?

Public Comments

1. Yes it is because a high refractive index has better reflecting properties ..... Fibre optics work via signals of light .... Using a material with a high index will therefore prove to be the best choice.... :-)
2. I'm a bit rust on physics having left my degree a few years ago but I think the answer is NO - the refractive index measures how much the light will refract as it enters the material, leaving one of a different density - as in Air. It is based upon n = c/vp, n being the refractive index, c the speed of light in a vacuum and vp the velocity in the substance, basically it only comes in to play at the border between 2 substances, so when inside a substance it should not effect how it reflects off of the outer casing of fibre optics.
3. fibre optics use two layers the inner with a lowere refractive index than the outer. since it works on the principle of total internal reflection of a light source in the inner part. any light that does not exceed the brewster angle will be leaked to the second layer but since that has a higher refractive index it will undergo total internal replection again thus minimising the loss of information
4. The refractive index of the fibre will only determine the speed of propagation of the signals v=c/n. The only requirement is nf>nc>nair where n = refractive indices of fibre, cladding and air resp (n=1 essentially for air). You are only really concerned whether the angle of the cone of available rays from the light source >ic the critical angle of incidence for total internal reflection, and this can be arranged using a suitable aperture. A far bigger issue is the purity of the glass as impurities lead to scattering and attenuation of signal.