In this 5 min 30 Sec video Mr. Bill Hammack (Engineerguy) from Department of Chemical & Biomolecular Engineering, University of Illinois – Urbana shows how a fiber optic cable works using a bucket of Propylene glycol and a laser pointer.
Source: http://www.engineerguy.com/videos.htm
Click here for more about Fibre Optic Cable
Click here to know more about Propylene glycol
More on Pulse Code Modulation here
Source: http://www.engineerguy.com/videos.htm
Click here for more about Fibre Optic Cable
Click here to know more about Propylene glycol
More on Pulse Code Modulation here