Graded-index Multi-mode Fibre
Advantages:
• Allows the use of non-coherent optical light source, e.g. LED's
• Facilitates connecting together similar fibres
• Imposes lower tolerance requirements on fibre connectors.
• Reduced dispersion compared with STMMF
Disadvantages:
• Lower bandwidth compared with STSMF
• High power loss compared with the STSMF
Step-index Single-mode Fibre
Advantages:
• Only one mode is allowed due to diffraction/interference effects.
• Allows the use high power laser source
• Facilitates fusion splicing similar fibres
• Low dispersion, therefore high bandwidth (a few GHz).
• Low loss (0.1 dB/km)
Disadvantages:
• Cost