Can Glass Guide Light?
The secret is total internal reflection!
By playing on the difference between two refractive indices,
it is possible to guide light from one point to another in
a glass thread.
Remember!
Total Internal Reflection happens for:
beams passing from a more
dense to a less dense material:
this is the case since the glass has a
higher refractivity than
air
incident angle greater than
the critical angle: the blue
ray is reflected back into the glass and the
red ray
is refracted
