[Goptical] Total internal reflection

[Karl D.D. Willis]

Hi all,

Firstly, thanks for the continuing development of goptical, it looks very 
promising.

I am interested in using goptical for simulating the total internal reflection 
that occurs inside fiber optics.
I have been playing around with the examples provided, but am a little stumped 
as to how best to proceed.

Are there any examples that deal with total internal reflection?
Or do you have any suggestions about how to proceed and what goptical objects 
should be used?

Any advise would be much appreciated.

Kind Regards,

Karl