Fiber Optics Type

• There are two types of glass fiber optics.
  
• They are called Singlemode (SM) and Multimode (MM).
  
• The difference lies on the diameter of the fiber optics core. 
  
• Singlemode has only one size of fiber optics core diameter i.e. 9 micron.
  
• Multimode basically has two sizes of fiber optics core diameter              i.e. 50 micron and 62.5 micron.
• However, fiber optics cladding diameter for both MM and SM remains at 125 micron.

How big is a MICRON ?

Basically human hair size is approximately 100 micron but the size of both multimode and singlemode core size is 50 micron or 62.5 micron and 9 micron respectively. 
One can conclude that human hair size is thicker than the size of fiber optics core !!!