RI measurement of glass fibres

[ZEB31]

Does anybody know how to measure the refractive index of a glass fibre (e-glass/s-glass etc)? I can get the range of liquids I need but I can't find any information on the technique itself.

Grateful for any help/direction

 

[randi]

Edmund Scientific provides the basic definiton of refractive index as follows, which you may be able to follow in any physics book also:

Index of refraction =Speed of light in vacuum/ speeed of light in medium.

Their optics and optical instruments catalog shows the values of the refractive index for various types of glass, e.g.fused silica,borofloat,prex 7740, zerodur etc. Typical values for this type of glass is shown to be respectively 1.458, 1.472,1.474 etc.

They also sell refractrometers, that measure the reractive index of liquids and solids in the range from 1.4 to about 1.7, and sell for more than $ 1000 U.S. Check them out at

http://www.edsci.com

Good luck with your reaseach.

 

[IRstuff]

Here's a couple of sites that describe refractometry:

http://www.chem.orst.edu/ch361-464/ch362/refract02.htm

http://www.c-f-c.com/supportdocs/refract.htm

As you can see, since it's absurdly difficult to measure the change in the speed of light, we take advantage of Snell's law to directly measure the change in angle of a beam of light crossing the interface, which is a direct consequence of the index change.

TTFN