Flashcards
Optical Fibers
Cards in this deck (12)
- 1Optical Fibers are made up of 2 sections. What are they?Core and cladding
- 2What is the purpose of the cladding?Protect the core from scratches
Increase critical angle (for TIR)
Prevents crossover of signal
Increases rate of data transfer - 3Pulse Send / Pulse Received diagram:
- 4What is multimode / modal dispersion?Where the received pulse has a lower amplitude due to energy being lost within the fibre
Also a longer time is caused by pulse broadening - 5What is a result of multimode?Pulse broadening
- 6How does pulse broadening effect the signal?Not as much data per second transferred
(or confused signal) - 7Pulse broadening Pulse send / Pulse received diagram:
- 8How to reduce multimode:1. Ensure core and cladding have very similar refractive indices so critical angle is high
2. Ensure optical fibre is very narrow - 9Reducing multimode diagram (example):
- 10What is material dispersion?Where violet travels more slowly than red light in a given medium, therefore if white light is used, a white pulse will become a broad spectrum of colours
- 11Material dispersion pulse sent / pulse received diagram:
- 12How to reduce material dispersion:Use monochromatic light